Add checkstyle rule for 'synchronized' on Manager.getInstanceFor()

Fixes SMACK-865.

config/checkstyle.xml

@@ -6,6 +6,11 @@
 	<module name="SuppressionFilter">
 		<property name="file" value="config/suppressions.xml"/>
 	</module>
+	<module name="SuppressWithPlainTextCommentFilter">
+		<property name="offCommentFormat" value="CHECKSTYLE\:OFF\:(\w+)"/>
+		<property name="onCommentFormat" value="CHECKSTYLE\:ON\:(\w+)"/>
+		<property name="checkFormat" value="$1"/>
+	</module>
 	<module name="Header">
 		<property name="headerFile" value="config/${checkstyleLicenseHeader}.txt"/>
 		<property name="ignoreLines" value="3"/>
@@ -61,6 +66,14 @@
 		<property name="format" value="^\s*//[^\s]"/>
 		<property name="message" value="Comment start ('//') followed by non-space character. You would not continue after a punctuation without a space, would you?"/>
 	</module>
+	<!-- Check for synchronized keyword on Manager's static
+	     getInstanceFor() method. Note that if XMPPConnection is every
+	     replaced with something else, then we need to change it here
+	     too. -->
+	<module name="RegexpSingleline">
+		<property name="format" value="^\s*public(?!.*synchronized).*getInstanceFor\(XMPPConnection.*$"/>
+		<property name="message" value="getInstanceFor() should be synchronized"/>
+	</module>
 	<module name="JavadocPackage"/>
 	<module name="TreeWalker">
 		<module name="SuppressionCommentFilter"/>
@@ -89,6 +102,11 @@
 			<property name="message" value="Usage of println"/>
 			<property name="ignoreComments" value="true"/>
 		</module>
+		<module name="RegexpSinglelineJava">
+			<property name="format" value="Boolean\.valueOf\("/>
+			<property name="message" value="Usage Boolean.valueOf(), consider using ParserUtils.parseXmlBoolean() instead (if you want to parse xs:boolean values)"/>
+			<property name="ignoreComments" value="true"/>
+		</module>
 		<module name="RegexpSinglelineJava">
 			<property name="format" value="^\t+"/>
 			<property name="message" value="Indent must not use tab characters. Use space instead."/>

resources/releasedocs/changelog.html

@@ -141,6 +141,74 @@ hr {
 
 	<div id="pageBody">
 
+<h2>4.3.3 -- <span style="font-weight: normal;">2019-03-14</span></h2>
+
+<h2>        Bug
+</h2>
+<ul>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-856'>SMACK-856</a>] -         Smack fails under JDK 11 because com.sun.jndi.dns.DnsContextFactory is not inaccessible
+</li>
+</ul>
+
+<h2>        Improvement
+</h2>
+<ul>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-858'>SMACK-858</a>] -         Dependency version specifier of jxmpp and MiniDNS include alpha/beta/... versions of the follow up version when Maven is used
+</li>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-859'>SMACK-859</a>] -         MultiUserChat enter() should reset the timeout of the collector waiting for the final self presence to prevent timeouts for large MUCs
+</li>
+</ul>
+
+<h2>4.3.2 -- <span style="font-weight: normal;">2019-02-22</span></h2>
+
+<h2>        Bug
+</h2>
+<ul>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-842'>SMACK-842</a>] -         The RFC 3920 xml-not-well-formed error condition should be handled in stream error not a stanza error
+</li>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-843'>SMACK-843</a>] -         ManManager.pagePrevious() pages into the wrong direction
+</li>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-844'>SMACK-844</a>] -         Check if bounded unacknowledged stanzas queue is full before adding to it to avoid IllegalStateException
+</li>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-845'>SMACK-845</a>] -         Ensure that IQ response &#39;to&#39; address and ID are set correctly
+</li>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-846'>SMACK-846</a>] -         XMPPTCPConnection does not wait for stream features after authentication if compression is disabled
+</li>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-848'>SMACK-848</a>] -         Make MultiUserChat.leave() wait for response
+</li>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-850'>SMACK-850</a>] -         DeliveryReceiptManager should not send receipts with messages of type &#39;groupchat&#39;
+</li>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-855'>SMACK-855</a>] -         XMPPTCPConnection sometimes has two writer threads running
+</li>
+</ul>
+
+<h2>        Improvement
+</h2>
+<ul>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-847'>SMACK-847</a>] -         Make TCP socket connection attempt interruptable
+</li>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-849'>SMACK-849</a>] -         Smack Local SOCKS5 Proxy thread should be marked as daemon thread
+</li>
+</ul>
+
+<h2>4.3.1 -- <span style="font-weight: normal;">2018-10-14</span></h2>
+	  
+<h2>        Bug
+</h2>
+<ul>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-833'>SMACK-833</a>] -         XMLUtil.prettyFormatXml() throws on some Android devices
+</li>
+</ul>
+                    
+<h2>        Improvement
+</h2>
+<ul>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-829'>SMACK-829</a>] -         Disconnect BOSH client on shutdown
+</li>
+<li>[<a href='https://issues.igniterealtime.org/browse/SMACK-838'>SMACK-838</a>] -         FormField.getFirstValue() throws IndexOutOfBoundsException if there are no values
+</li>
+</ul>
+
 <h2>4.3.0 -- <span style="font-weight: normal;">2018-08-02</span></h2>
 
 <h2>        Bug

smack-bosh/build.gradle

@@ -4,5 +4,7 @@ This API is considered beta quality."""
 
 dependencies {
 	compile project(':smack-core')
-	compile 'org.igniterealtime.jbosh:jbosh:[0.9,0.10)'
+	// See https://issues.igniterealtime.org/browse/SMACK-858 and
+	// comment in version.gradle why the specify the version this way.
+	compile 'org.igniterealtime.jbosh:jbosh:[0.9.1,0.9.999]'
 }

smack-bosh/src/main/java/org/jivesoftware/smack/bosh/BOSHConfiguration.java

@@ -19,6 +19,8 @@ package org.jivesoftware.smack.bosh;
 
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.util.HashMap;
+import java.util.Map;
 
 import org.jivesoftware.smack.ConnectionConfiguration;
 import org.jivesoftware.smack.proxy.ProxyInfo;
@@ -34,6 +36,7 @@ public final class BOSHConfiguration extends ConnectionConfiguration {
 
     private final boolean https;
     private final String file;
+    private Map<String, String> httpHeaders;
 
     private BOSHConfiguration(Builder builder) {
         super(builder);
@@ -49,6 +52,7 @@ public final class BOSHConfiguration extends ConnectionConfiguration {
         } else {
             file = builder.file;
         }
+        httpHeaders = builder.httpHeaders;
     }
 
     public boolean isProxyEnabled() {
@@ -76,6 +80,10 @@ public final class BOSHConfiguration extends ConnectionConfiguration {
         return new URI((https ? "https://" : "http://") + this.host + ":" + this.port + file);
     }
 
+    public Map<String, String> getHttpHeaders() {
+        return httpHeaders;
+    }
+
     public static Builder builder() {
         return new Builder();
     }
@@ -83,6 +91,7 @@ public final class BOSHConfiguration extends ConnectionConfiguration {
     public static final class Builder extends ConnectionConfiguration.Builder<Builder, BOSHConfiguration> {
         private boolean https;
         private String file;
+        private Map<String, String> httpHeaders = new HashMap<>();
 
         private Builder() {
         }
@@ -101,6 +110,11 @@ public final class BOSHConfiguration extends ConnectionConfiguration {
             return this;
         }
 
+        public Builder addHttpHeader(String name, String value) {
+            httpHeaders.put(name, value);
+            return this;
+        }
+
         @Override
         public BOSHConfiguration build() {
             return new BOSHConfiguration(this);

smack-bosh/src/main/java/org/jivesoftware/smack/bosh/XMPPBOSHConnection.java

@@ -22,6 +22,7 @@ import java.io.PipedReader;
 import java.io.PipedWriter;
 import java.io.StringReader;
 import java.io.Writer;
+import java.util.Map;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -156,6 +157,9 @@ public class XMPPBOSHConnection extends AbstractXMPPConnection {
             if (config.isProxyEnabled()) {
                 cfgBuilder.setProxy(config.getProxyAddress(), config.getProxyPort());
             }
+            for (Map.Entry<String, String> h : config.getHttpHeaders().entrySet()) {
+                cfgBuilder.addHttpHeader(h.getKey(), h.getValue());
+            }
             client = BOSHClient.create(cfgBuilder.build());
 
             client.addBOSHClientConnListener(new BOSHConnectionListener());
@@ -263,6 +267,11 @@ public class XMPPBOSHConnection extends AbstractXMPPConnection {
             client = null;
         }
 
+        instantShutdown();
+    }
+
+    @Override
+    public void instantShutdown() {
         setWasAuthenticated();
         sessionID = null;
         done = true;

smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java

@@ -26,6 +26,7 @@ import java.util.LinkedHashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.Queue;
 import java.util.Set;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.CopyOnWriteArraySet;
@@ -235,7 +236,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
      * stanza is send by the server. This is set to true once the last feature stanza has been
      * parsed.
      */
-    protected final SynchronizationPoint<Exception> lastFeaturesReceived = new SynchronizationPoint<Exception>(
+    protected final SynchronizationPoint<SmackException> lastFeaturesReceived = new SynchronizationPoint<>(
                     AbstractXMPPConnection.this, "last stream features received from server");
 
     /**
@@ -297,7 +298,18 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         }
     });
 
-    private static final AsyncButOrdered<AbstractXMPPConnection> ASYNC_BUT_ORDERED = new AsyncButOrdered<>();
+    protected static final AsyncButOrdered<AbstractXMPPConnection> ASYNC_BUT_ORDERED = new AsyncButOrdered<>();
+
+    /**
+     * An executor which uses {@link #asyncGoLimited(Runnable)} to limit the number of asynchronously processed runnables
+     * per connection.
+     */
+    private final Executor limitedExcutor = new Executor() {
+        @Override
+        public void execute(Runnable runnable) {
+            asyncGoLimited(runnable);
+        }
+    };
 
     /**
      * The used host to establish the connection to
@@ -314,6 +326,9 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
      */
     protected boolean authenticated = false;
 
+    // TODO: Migrate to ZonedDateTime once Smack's minimum required Android SDK level is 26 (8.0, Oreo) or higher.
+    protected long authenticatedConnectionInitiallyEstablishedTimestamp;
+
     /**
      * Flag that indicates if the user was authenticated with the server when the connection
      * to the server was closed (abruptly or not).
@@ -381,6 +396,12 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
     @Override
     public abstract boolean isUsingCompression();
 
+    protected void initState() {
+        saslFeatureReceived.init();
+        lastFeaturesReceived.init();
+        tlsHandled.init();
+    }
+
     /**
      * Establishes a connection to the XMPP server. It basically
      * creates and maintains a connection to the server.
@@ -399,21 +420,23 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         throwAlreadyConnectedExceptionIfAppropriate();
 
         // Reset the connection state
+        initState();
         saslAuthentication.init();
-        saslFeatureReceived.init();
-        lastFeaturesReceived.init();
-        tlsHandled.init();
         streamId = null;
 
-        // Perform the actual connection to the XMPP service
+        try {
-        connectInternal();
+            // Perform the actual connection to the XMPP service
+            connectInternal();
 
-        // If TLS is required but the server doesn't offer it, disconnect
+            // If TLS is required but the server doesn't offer it, disconnect
-        // from the server and throw an error. First check if we've already negotiated TLS
+            // from the server and throw an error. First check if we've already negotiated TLS
-        // and are secure, however (features get parsed a second time after TLS is established).
+            // and are secure, however (features get parsed a second time after TLS is established).
-        if (!isSecureConnection() && getConfiguration().getSecurityMode() == SecurityMode.required) {
+            if (!isSecureConnection() && getConfiguration().getSecurityMode() == SecurityMode.required) {
-            shutdown();
+                throw new SecurityRequiredByClientException();
-            throw new SecurityRequiredByClientException();
+            }
+        } catch (SmackException | IOException | XMPPException | InterruptedException e) {
+            instantShutdown();
+            throw e;
         }
 
         // Make note of the fact that we're now connected.
@@ -550,7 +573,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         // - the servers last features stanza has been parsed
         // - the timeout occurs
         LOGGER.finer("Waiting for last features to be received before continuing with resource binding");
-        lastFeaturesReceived.checkIfSuccessOrWait();
+        lastFeaturesReceived.checkIfSuccessOrWaitOrThrow();
 
 
         if (!hasFeature(Bind.ELEMENT, Bind.NAMESPACE)) {
@@ -582,6 +605,9 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
     }
 
     protected void afterSuccessfulLogin(final boolean resumed) throws NotConnectedException, InterruptedException {
+        if (!resumed) {
+            authenticatedConnectionInitiallyEstablishedTimestamp = System.currentTimeMillis();
+        }
         // Indicate that we're now authenticated.
         this.authenticated = true;
 
@@ -763,6 +789,11 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
      */
     protected abstract void shutdown();
 
+    /**
+     * Performs an unclean disconnect and shutdown of the connection. Does not send a closing stream stanza.
+     */
+    public abstract void instantShutdown();
+
     @Override
     public void addConnectionListener(ConnectionListener connectionListener) {
         if (connectionListener == null) {
@@ -1097,6 +1128,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         if (packet instanceof IQ) {
             final IQ iq = (IQ) packet;
             if (iq.isRequestIQ()) {
+                final IQ iqRequest = iq;
                 final String key = XmppStringUtils.generateKey(iq.getChildElementName(), iq.getChildElementNamespace());
                 IQRequestHandler iqRequestHandler;
                 final IQ.Type type = iq.getType();
@@ -1146,7 +1178,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
                         executorService = ASYNC_BUT_ORDERED.asExecutorFor(this);
                         break;
                     case async:
-                        executorService = CACHED_EXECUTOR_SERVICE;
+                        executorService = limitedExcutor;
                         break;
                     }
                     final IQRequestHandler finalIqRequestHandler = iqRequestHandler;
@@ -1162,6 +1194,11 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
                                 // e.g. to avoid presence leaks.
                                 return;
                             }
+
+                            assert (response.getType() == IQ.Type.result || response.getType() == IQ.Type.error);
+
+                            response.setTo(iqRequest.getFrom());
+                            response.setStanzaId(iqRequest.getStanzaId());
                             try {
                                 sendStanza(response);
                             }
@@ -1191,7 +1228,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         }
 
         for (final StanzaListener listener : listenersToNotify) {
-            asyncGo(new Runnable() {
+            asyncGoLimited(new Runnable() {
                 @Override
                 public void run() {
                     try {
@@ -1710,6 +1747,18 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         return lastStanzaReceived;
     }
 
+    /**
+     * Get the timestamp when the connection was the first time authenticated, i.e., when the first successful login was
+     * performed. Note that this value is not reset on disconnect, so it represents the timestamp from the last
+     * authenticated connection. The value is also not reset on stream resumption.
+     *
+     * @return the timestamp or {@code null}.
+     * @since 4.3.3
+     */
+    public final long getAuthenticatedConnectionInitiallyEstablishedTimestamp() {
+        return authenticatedConnectionInitiallyEstablishedTimestamp;
+    }
+
     /**
      * Install a parsing exception callback, which will be invoked once an exception is encountered while parsing a
      * stanza.
@@ -1736,6 +1785,75 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         return getClass().getSimpleName() + '[' + localEndpointString + "] (" + getConnectionCounter() + ')';
     }
 
+    /**
+     * A queue of deferred runnables that where not executed immediately because {@link #currentAsyncRunnables} reached
+     * {@link #maxAsyncRunnables}. Note that we use a {@code LinkedList} in order to avoid space blowups in case the
+     * list ever becomes very big and shrinks again.
+     */
+    private final Queue<Runnable> deferredAsyncRunnables = new LinkedList<>();
+
+    private int deferredAsyncRunnablesCount;
+
+    private int deferredAsyncRunnablesCountPrevious;
+
+    private int maxAsyncRunnables = SmackConfiguration.getDefaultConcurrencyLevelLimit();
+
+    private int currentAsyncRunnables;
+
+    protected void asyncGoLimited(final Runnable runnable) {
+        Runnable wrappedRunnable = new Runnable() {
+            @Override
+            public void run() {
+                runnable.run();
+
+                synchronized (deferredAsyncRunnables) {
+                    Runnable defferredRunnable = deferredAsyncRunnables.poll();
+                    if (defferredRunnable == null) {
+                        currentAsyncRunnables--;
+                    } else {
+                        deferredAsyncRunnablesCount--;
+                        asyncGo(defferredRunnable);
+                    }
+                }
+            }
+        };
+
+        synchronized (deferredAsyncRunnables) {
+            if (currentAsyncRunnables < maxAsyncRunnables) {
+                currentAsyncRunnables++;
+                asyncGo(wrappedRunnable);
+            } else {
+                deferredAsyncRunnablesCount++;
+                deferredAsyncRunnables.add(wrappedRunnable);
+            }
+
+            final int HIGH_WATERMARK = 100;
+            final int INFORM_WATERMARK = 20;
+
+            final int deferredAsyncRunnablesCount = this.deferredAsyncRunnablesCount;
+
+            if (deferredAsyncRunnablesCount >= HIGH_WATERMARK
+                    && deferredAsyncRunnablesCountPrevious < HIGH_WATERMARK) {
+                LOGGER.log(Level.WARNING, "High watermark of " + HIGH_WATERMARK + " simultaneous executing runnables reached");
+            } else if (deferredAsyncRunnablesCount >= INFORM_WATERMARK
+                    && deferredAsyncRunnablesCountPrevious < INFORM_WATERMARK) {
+                LOGGER.log(Level.INFO, INFORM_WATERMARK + " simultaneous executing runnables reached");
+            }
+
+            deferredAsyncRunnablesCountPrevious = deferredAsyncRunnablesCount;
+        }
+    }
+
+    public void setMaxAsyncOperations(int maxAsyncOperations) {
+        if (maxAsyncOperations < 1) {
+            throw new IllegalArgumentException("Max async operations must be greater than 0");
+        }
+
+        synchronized (deferredAsyncRunnables) {
+            maxAsyncRunnables = maxAsyncOperations;
+        }
+    }
+
     protected static void asyncGo(Runnable runnable) {
         CACHED_EXECUTOR_SERVICE.execute(runnable);
     }

smack-core/src/main/java/org/jivesoftware/smack/AsyncButOrdered.java

@@ -55,6 +55,16 @@ public class AsyncButOrdered<K> {
 
     private final Map<K, Boolean> threadActiveMap = new WeakHashMap<>();
 
+    private final Executor executor;
+
+    public AsyncButOrdered() {
+        this(null);
+    }
+
+    public AsyncButOrdered(Executor executor) {
+        this.executor = executor;
+    }
+
     /**
      * Invoke the given {@link Runnable} asynchronous but ordered in respect to the given key.
      *
@@ -86,7 +96,11 @@ public class AsyncButOrdered<K> {
             if (newHandler) {
                 Handler handler = new Handler(keyQueue, key);
                 threadActiveMap.put(key, true);
-                AbstractXMPPConnection.asyncGo(handler);
+                if (executor == null) {
+                    AbstractXMPPConnection.asyncGo(handler);
+                } else {
+                    executor.execute(handler);
+                }
             }
         }
 

smack-core/src/main/java/org/jivesoftware/smack/ConnectionConfiguration.java

@@ -18,6 +18,7 @@
 package org.jivesoftware.smack;
 
 import java.net.InetAddress;
+import java.net.UnknownHostException;
 import java.security.KeyStore;
 import java.util.Arrays;
 import java.util.Collection;
@@ -45,6 +46,7 @@ import org.jxmpp.jid.impl.JidCreate;
 import org.jxmpp.jid.parts.Resourcepart;
 import org.jxmpp.stringprep.XmppStringprepException;
 import org.minidns.dnsname.DnsName;
+import org.minidns.util.InetAddressUtil;
 
 /**
  * Configuration to use while establishing the connection to the server.
@@ -171,6 +173,14 @@ public abstract class ConnectionConfiguration {
 
     }
 
+    DnsName getHost() {
+        return host;
+    }
+
+    InetAddress getHostAddress() {
+        return hostAddress;
+    }
+
     /**
      * Returns the server name of the target server.
      *
@@ -642,6 +652,33 @@ public abstract class ConnectionConfiguration {
             return getThis();
         }
 
+        /**
+         * Set the host to connect to by either its fully qualified domain name (FQDN) or its IP.
+         *
+         * @param fqdnOrIp a CharSequence either representing the FQDN or the IP of the host.
+         * @return a reference to this builder.
+         * @see #setHost(DnsName)
+         * @see #setHostAddress(InetAddress)
+         * @since 4.3.2
+         */
+        public B setHostAddressByNameOrIp(CharSequence fqdnOrIp) {
+            String fqdnOrIpString = fqdnOrIp.toString();
+            if (InetAddressUtil.isIpAddress(fqdnOrIp)) {
+                InetAddress hostInetAddress;
+                try {
+                    hostInetAddress = InetAddress.getByName(fqdnOrIpString);
+                }
+                catch (UnknownHostException e) {
+                    // Should never happen.
+                    throw new AssertionError(e);
+                }
+                setHostAddress(hostInetAddress);
+            } else {
+                setHost(fqdnOrIpString);
+            }
+            return getThis();
+        }
+
         public B setPort(int port) {
             if (port < 0 || port > 65535) {
                 throw new IllegalArgumentException(

smack-core/src/main/java/org/jivesoftware/smack/SmackConfiguration.java

@@ -365,4 +365,19 @@ public final class SmackConfiguration {
     public static void setUnknownIqRequestReplyMode(UnknownIqRequestReplyMode unknownIqRequestReplyMode) {
         SmackConfiguration.unknownIqRequestReplyMode = Objects.requireNonNull(unknownIqRequestReplyMode, "Must set mode");
     }
+
+    private static final int defaultConcurrencyLevelLimit;
+
+    static {
+        int availableProcessors = Runtime.getRuntime().availableProcessors();
+        if (availableProcessors < 8) {
+            defaultConcurrencyLevelLimit = 8;
+        } else {
+            defaultConcurrencyLevelLimit = (int) (availableProcessors * 1.1);
+        }
+    }
+
+    public static int getDefaultConcurrencyLevelLimit() {
+        return defaultConcurrencyLevelLimit;
+    }
 }

smack-core/src/main/java/org/jivesoftware/smack/SmackException.java

@@ -93,13 +93,24 @@ public class SmackException extends Exception {
             return new NoResponseException(sb.toString());
         }
 
+        @Deprecated
+        // TODO: Remove in Smack 4.4.
         public static NoResponseException newWith(XMPPConnection connection,
                         StanzaCollector collector) {
             return newWith(connection, collector.getStanzaFilter());
         }
 
+        public static NoResponseException newWith(long timeout,
+                        StanzaCollector collector) {
+            return newWith(timeout, collector.getStanzaFilter());
+        }
+
         public static NoResponseException newWith(XMPPConnection connection, StanzaFilter filter) {
-            final StringBuilder sb = getWaitingFor(connection);
+            return newWith(connection.getReplyTimeout(), filter);
+        }
+
+        public static NoResponseException newWith(long timeout, StanzaFilter filter) {
+            final StringBuilder sb = getWaitingFor(timeout);
             sb.append(" Waited for response using: ");
             if (filter != null) {
                 sb.append(filter.toString());
@@ -112,7 +123,10 @@ public class SmackException extends Exception {
         }
 
         private static StringBuilder getWaitingFor(XMPPConnection connection) {
-            final long replyTimeout = connection.getReplyTimeout();
+            return getWaitingFor(connection.getReplyTimeout());
+        }
+
+        private static StringBuilder getWaitingFor(final long replyTimeout) {
             final StringBuilder sb = new StringBuilder(256);
             sb.append("No response received within reply timeout. Timeout was "
                             + replyTimeout + "ms (~"
@@ -334,4 +348,16 @@ public class SmackException extends Exception {
             super("Resource binding was not offered by server");
         }
     }
+
+    public static class SmackWrappedException extends SmackException {
+
+        /**
+         *
+         */
+        private static final long serialVersionUID = 1L;
+
+        public SmackWrappedException(Exception exception) {
+            super(exception);
+        }
+    }
 }

smack-core/src/main/java/org/jivesoftware/smack/SmackFuture.java

@@ -16,11 +16,18 @@
  */
 package org.jivesoftware.smack;
 
+import java.io.IOException;
+import java.net.Socket;
+import java.net.SocketAddress;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.net.SocketFactory;
 
 import org.jivesoftware.smack.packet.Stanza;
 import org.jivesoftware.smack.util.CallbackRecipient;
@@ -29,6 +36,8 @@ import org.jivesoftware.smack.util.SuccessCallback;
 
 public abstract class SmackFuture<V, E extends Exception> implements Future<V>, CallbackRecipient<V, E> {
 
+    private static final Logger LOGGER = Logger.getLogger(SmackFuture.class.getName());
+
     private boolean cancelled;
 
     protected V result;
@@ -94,7 +103,7 @@ public abstract class SmackFuture<V, E extends Exception> implements Future<V>,
     @Override
     public final synchronized V get() throws InterruptedException, ExecutionException {
         while (result == null && exception == null && !cancelled) {
-            wait();
+            futureWait();
         }
 
         return getOrThrowExecutionException();
@@ -102,7 +111,7 @@ public abstract class SmackFuture<V, E extends Exception> implements Future<V>,
 
     public final synchronized V getOrThrow() throws E, InterruptedException {
         while (result == null && exception == null && !cancelled) {
-            wait();
+            futureWait();
         }
 
         if (exception != null) {
@@ -124,7 +133,7 @@ public abstract class SmackFuture<V, E extends Exception> implements Future<V>,
         while (result != null && exception != null) {
             final long waitTimeRemaining = deadline - System.currentTimeMillis();
             if (waitTimeRemaining > 0) {
-                wait(waitTimeRemaining);
+                futureWait(waitTimeRemaining);
             }
         }
 
@@ -162,6 +171,15 @@ public abstract class SmackFuture<V, E extends Exception> implements Future<V>,
         }
     }
 
+    protected final void futureWait() throws InterruptedException {
+        futureWait(0);
+    }
+
+    @SuppressWarnings("WaitNotInLoop")
+    protected void futureWait(long timeout) throws InterruptedException {
+        wait(timeout);
+    }
+
     public static class InternalSmackFuture<V, E extends Exception> extends SmackFuture<V, E> {
         public final synchronized void setResult(V result) {
             this.result = result;
@@ -178,6 +196,64 @@ public abstract class SmackFuture<V, E extends Exception> implements Future<V>,
         }
     }
 
+    public static class SocketFuture extends InternalSmackFuture<Socket, IOException> {
+        private final Socket socket;
+
+        private final Object wasInterruptedLock = new Object();
+
+        private boolean wasInterrupted;
+
+        public SocketFuture(SocketFactory socketFactory) throws IOException {
+            socket = socketFactory.createSocket();
+        }
+
+        @Override
+        protected void futureWait(long timeout) throws InterruptedException {
+            try {
+                super.futureWait(timeout);
+            } catch (InterruptedException interruptedException) {
+                synchronized (wasInterruptedLock) {
+                    wasInterrupted = true;
+                    if (!socket.isClosed()) {
+                        closeSocket();
+                    }
+                }
+                throw interruptedException;
+            }
+        }
+
+        public void connectAsync(final SocketAddress socketAddress, final int timeout) {
+            AbstractXMPPConnection.asyncGo(new Runnable() {
+                @Override
+                public void run() {
+                    try {
+                        socket.connect(socketAddress, timeout);
+                    }
+                    catch (IOException e) {
+                        setException(e);
+                        return;
+                    }
+                    synchronized (wasInterruptedLock) {
+                        if (wasInterrupted) {
+                            closeSocket();
+                            return;
+                        }
+                    }
+                    setResult(socket);
+                }
+            });
+        }
+
+        private void closeSocket() {
+            try {
+                socket.close();
+            }
+            catch (IOException ioException) {
+                LOGGER.log(Level.WARNING, "Could not close socket", ioException);
+            }
+        }
+    }
+
     public abstract static class InternalProcessStanzaSmackFuture<V, E extends Exception> extends InternalSmackFuture<V, E>
                     implements StanzaListener, ExceptionCallback<E> {
 

smack-core/src/main/java/org/jivesoftware/smack/StanzaCollector.java

@@ -262,7 +262,7 @@ public class StanzaCollector {
             if (!connection.isConnected()) {
                 throw new NotConnectedException(connection, packetFilter);
             }
-            throw NoResponseException.newWith(connection, this);
+            throw NoResponseException.newWith(timeout, this);
         }
 
         XMPPErrorException.ifHasErrorThenThrow(result);

smack-core/src/main/java/org/jivesoftware/smack/SynchronizationPoint.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright © 2014-2015 Florian Schmaus
+ * Copyright © 2014-2019 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@ import java.util.concurrent.locks.Lock;
 
 import org.jivesoftware.smack.SmackException.NoResponseException;
 import org.jivesoftware.smack.SmackException.NotConnectedException;
+import org.jivesoftware.smack.SmackException.SmackWrappedException;
 import org.jivesoftware.smack.packet.Nonza;
 import org.jivesoftware.smack.packet.Stanza;
 import org.jivesoftware.smack.packet.TopLevelStreamElement;
@@ -37,6 +38,7 @@ public class SynchronizationPoint<E extends Exception> {
     // same memory synchronization effects as synchronization block enter and leave.
     private State state;
     private E failureException;
+    private SmackWrappedException smackWrappedExcpetion;
 
     /**
      * Construct a new synchronization point for the given connection.
@@ -59,6 +61,7 @@ public class SynchronizationPoint<E extends Exception> {
         connectionLock.lock();
         state = State.Initial;
         failureException = null;
+        smackWrappedExcpetion = null;
         connectionLock.unlock();
     }
 
@@ -71,7 +74,7 @@ public class SynchronizationPoint<E extends Exception> {
      * @throws InterruptedException if the connection is interrupted.
      * @return <code>null</code> if synchronization point was successful, or the failure Exception.
      */
-    public E sendAndWaitForResponse(TopLevelStreamElement request) throws NoResponseException,
+    public Exception sendAndWaitForResponse(TopLevelStreamElement request) throws NoResponseException,
                     NotConnectedException, InterruptedException {
         assert (state == State.Initial);
         connectionLock.lock();
@@ -103,15 +106,14 @@ public class SynchronizationPoint<E extends Exception> {
      * @throws NoResponseException if no response was received.
      * @throws NotConnectedException if the connection is not connected.
      * @throws InterruptedException if the connection is interrupted.
+     * @throws SmackWrappedException in case of a wrapped exception;
      */
     public void sendAndWaitForResponseOrThrow(Nonza request) throws E, NoResponseException,
-                    NotConnectedException, InterruptedException {
+                    NotConnectedException, InterruptedException, SmackWrappedException {
         sendAndWaitForResponse(request);
         switch (state) {
         case Failure:
-            if (failureException != null) {
+            throwException();
-                throw failureException;
-            }
             break;
         default:
             // Success, do nothing
@@ -123,11 +125,12 @@ public class SynchronizationPoint<E extends Exception> {
      * @throws NoResponseException if there was no response marking the synchronization point as success or failed.
      * @throws E if there was a failure
      * @throws InterruptedException if the connection is interrupted.
+     * @throws SmackWrappedException in case of a wrapped exception;
      */
-    public void checkIfSuccessOrWaitOrThrow() throws NoResponseException, E, InterruptedException {
+    public void checkIfSuccessOrWaitOrThrow() throws NoResponseException, E, InterruptedException, SmackWrappedException {
         checkIfSuccessOrWait();
         if (state == State.Failure) {
-            throw failureException;
+            throwException();
         }
     }
 
@@ -137,7 +140,7 @@ public class SynchronizationPoint<E extends Exception> {
      * @throws InterruptedException
      * @return <code>null</code> if synchronization point was successful, or the failure Exception.
      */
-    public E checkIfSuccessOrWait() throws NoResponseException, InterruptedException {
+    public Exception checkIfSuccessOrWait() throws NoResponseException, InterruptedException {
         connectionLock.lock();
         try {
             switch (state) {
@@ -145,7 +148,7 @@ public class SynchronizationPoint<E extends Exception> {
             case Success:
                 return null;
             case Failure:
-                return failureException;
+                return getException();
             default:
                 // Do nothing
                 break;
@@ -198,6 +201,24 @@ public class SynchronizationPoint<E extends Exception> {
         }
     }
 
+    /**
+     * Report this synchronization point as failed because of the given exception. The {@code failureException} must be set.
+     *
+     * @param exception the exception causing this synchronization point to fail.
+     */
+    public void reportGenericFailure(SmackWrappedException exception) {
+        assert exception != null;
+        connectionLock.lock();
+        try {
+            state = State.Failure;
+            this.smackWrappedExcpetion = exception;
+            condition.signalAll();
+        }
+        finally {
+            connectionLock.unlock();
+        }
+    }
+
     /**
      * Check if this synchronization point was successful.
      *
@@ -213,6 +234,16 @@ public class SynchronizationPoint<E extends Exception> {
         }
     }
 
+    public boolean isNotInInitialState() {
+        connectionLock.lock();
+        try {
+            return state != State.Initial;
+        }
+        finally {
+            connectionLock.unlock();
+        }
+    }
+
     /**
      * Check if this synchronization point has its request already sent.
      *
@@ -256,6 +287,20 @@ public class SynchronizationPoint<E extends Exception> {
         }
     }
 
+    private Exception getException() {
+        if (failureException != null) {
+            return failureException;
+        }
+        return smackWrappedExcpetion;
+    }
+
+    private void throwException() throws E, SmackWrappedException {
+        if (failureException != null) {
+            throw failureException;
+        }
+        throw smackWrappedExcpetion;
+    }
+
     /**
      * Check for a response and throw a {@link NoResponseException} if there was none.
      * <p>
@@ -264,7 +309,7 @@ public class SynchronizationPoint<E extends Exception> {
      * @return <code>true</code> if synchronization point was successful, <code>false</code> on failure.
      * @throws NoResponseException
      */
-    private E checkForResponse() throws NoResponseException {
+    private Exception checkForResponse() throws NoResponseException {
         switch (state) {
         case Initial:
         case NoResponse:
@@ -273,7 +318,7 @@ public class SynchronizationPoint<E extends Exception> {
         case Success:
             return null;
         case Failure:
-            return failureException;
+            return getException();
         default:
             throw new AssertionError("Unknown state " + state);
         }

smack-core/src/main/java/org/jivesoftware/smack/packet/StanzaError.java

@@ -198,6 +198,12 @@ public class StanzaError extends AbstractError implements ExtensionElement {
     public String toString() {
         StringBuilder sb = new StringBuilder("XMPPError: ");
         sb.append(condition.toString()).append(" - ").append(type.toString());
+
+        String descriptiveText = getDescriptiveText();
+        if (descriptiveText != null) {
+            sb.append(" [").append(descriptiveText).append(']');
+        }
+
         if (errorGenerator != null) {
             sb.append(". Generated by ").append(errorGenerator);
         }
@@ -385,11 +391,6 @@ public class StanzaError extends AbstractError implements ExtensionElement {
         }
 
         public static Condition fromString(String string) {
-            // Backwards compatibility for older implementations still using RFC 3920. RFC 6120
-            // changed 'xml-not-well-formed' to 'not-well-formed'.
-            if ("xml-not-well-formed".equals(string)) {
-                string = "not-well-formed";
-            }
             string = string.replace('-', '_');
             Condition condition = null;
             try {

smack-core/src/main/java/org/jivesoftware/smack/packet/StreamError.java

@@ -186,6 +186,11 @@ public class StreamError extends AbstractError implements Nonza {
         }
 
         public static Condition fromString(String string) {
+            // Backwards compatibility for older implementations still using RFC 3920. RFC 6120
+            // changed 'xml-not-well-formed' to 'not-well-formed'.
+            if ("xml-not-well-formed".equals(string)) {
+                string = "not-well-formed";
+            }
             string = string.replace('-', '_');
             Condition condition = null;
             try {

smack-core/src/main/java/org/jivesoftware/smack/provider/IntrospectionProvider.java

@@ -123,7 +123,9 @@ public class IntrospectionProvider{
         case "java.lang.String":
             return value;
         case "boolean":
+            // CHECKSTYLE:OFF
             return Boolean.valueOf(value);
+            // CHECKSTYLE:ON
         case "int":
             return Integer.valueOf(value);
         case "long":

smack-core/src/main/java/org/jivesoftware/smack/proxy/HTTPProxySocketConnection.java

@@ -58,7 +58,7 @@ class HTTPProxySocketConnection implements ProxySocketConnection {
             proxyLine = "\r\nProxy-Authorization: Basic " + Base64.encode(username + ":" + password);
         }
         socket.getOutputStream().write((hostport + " HTTP/1.1\r\nHost: "
-            + hostport + proxyLine + "\r\n\r\n").getBytes("UTF-8"));
+            + host + ":" + port + proxyLine + "\r\n\r\n").getBytes("UTF-8"));
 
         InputStream in = socket.getInputStream();
         StringBuilder got = new StringBuilder(100);
@@ -115,7 +115,8 @@ class HTTPProxySocketConnection implements ProxySocketConnection {
         int code = Integer.parseInt(m.group(1));
 
         if (code != HttpURLConnection.HTTP_OK) {
-            throw new ProxyException(ProxyInfo.ProxyType.HTTP);
+            throw new ProxyException(ProxyInfo.ProxyType.HTTP,
+                "Error code in proxy response: " + code);
         }
     }
 

smack-core/src/main/java/org/jivesoftware/smack/util/ParserUtils.java

@@ -129,6 +129,27 @@ public class ParserUtils {
         return Resourcepart.from(resourcepartString);
     }
 
+    /**
+     * Prase a string to a boolean value as per "xs:boolean". Valid input strings are "true", "1" for true, and "false", "0" for false.
+     *
+     * @param booleanString the input string.
+     * @return the boolean representation of the input string
+     * @throws IllegalArgumentException if the input string is not valid.
+     * @since 4.3.2
+     */
+    public static boolean parseXmlBoolean(String booleanString) {
+        switch (booleanString) {
+        case "true":
+        case "1":
+            return true;
+        case "false":
+        case "0":
+            return false;
+        default:
+            throw new IllegalArgumentException(booleanString + " is not a valid boolean string");
+        }
+    }
+
     /**
      * Get the boolean value of an argument.
      *
@@ -141,7 +162,7 @@ public class ParserUtils {
         if (valueString == null)
             return null;
         valueString = valueString.toLowerCase(Locale.US);
-        return valueString.equals("true") || valueString.equals("0");
+        return parseXmlBoolean(valueString);
     }
 
     public static boolean getBooleanAttribute(XmlPullParser parser, String name,

smack-core/src/main/java/org/jivesoftware/smack/util/XmlUtil.java

@@ -35,7 +35,11 @@ public class XmlUtil {
     private static final TransformerFactory transformerFactory = TransformerFactory.newInstance();
 
     static {
-        transformerFactory.setAttribute("indent-number", 2);
+        try {
+            transformerFactory.setAttribute("indent-number", 2);
+        } catch (IllegalArgumentException e) {
+            LOGGER.log(Level.INFO, "XML TransformerFactory does not support indent-number attribute", e);
+        }
     }
 
     public static String prettyFormatXml(CharSequence xml) {

smack-core/src/test/java/org/jivesoftware/smack/ConnectionConfigurationTest.java

@@ -0,0 +1,79 @@
+/**
+ *
+ * Copyright 2018 Florian Schmaus.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smack;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+import org.jxmpp.jid.JidTestUtil;
+
+public class ConnectionConfigurationTest {
+
+    @Test
+    public void setIp() {
+        DummyConnectionConfiguration.Builder builder = newUnitTestBuilder();
+
+        final String ip = "192.168.0.1";
+        builder.setHostAddressByNameOrIp(ip);
+
+        DummyConnectionConfiguration connectionConfiguration = builder.build();
+        assertEquals('/' + ip, connectionConfiguration.getHostAddress().toString());
+    }
+
+    @Test
+    public void setFqdn() {
+        DummyConnectionConfiguration.Builder builder = newUnitTestBuilder();
+
+        final String fqdn = "foo.example.org";
+        builder.setHostAddressByNameOrIp(fqdn);
+
+        DummyConnectionConfiguration connectionConfiguration = builder.build();
+        assertEquals(fqdn, connectionConfiguration.getHost().toString());
+    }
+
+    private static DummyConnectionConfiguration.Builder newUnitTestBuilder() {
+        DummyConnectionConfiguration.Builder builder = DummyConnectionConfiguration.builder();
+        builder.setXmppDomain(JidTestUtil.DOMAIN_BARE_JID_1);
+        return builder;
+    }
+
+    private static final class DummyConnectionConfiguration extends ConnectionConfiguration {
+
+        protected DummyConnectionConfiguration(Builder builder) {
+            super(builder);
+        }
+
+        public static Builder builder() {
+            return new Builder();
+        }
+
+        private static final class Builder
+                        extends ConnectionConfiguration.Builder<Builder, DummyConnectionConfiguration> {
+
+            @Override
+            public DummyConnectionConfiguration build() {
+                return new DummyConnectionConfiguration(this);
+            }
+
+            @Override
+            protected Builder getThis() {
+                return this;
+            }
+
+        }
+    }
+}

smack-core/src/test/java/org/jivesoftware/smack/DummyConnection.java

@@ -100,6 +100,11 @@ public class DummyConnection extends AbstractXMPPConnection {
         callConnectionClosedListener();
     }
 
+    @Override
+    public void instantShutdown() {
+        shutdown();
+    }
+
     @Override
     public boolean isSecureConnection() {
         return false;
@@ -226,4 +231,5 @@ public class DummyConnection extends AbstractXMPPConnection {
             }
         }
     }
+
 }

smack-core/src/test/java/org/jivesoftware/smack/packet/StreamErrorTest.java

@@ -104,4 +104,22 @@ public class StreamErrorTest {
         assertNotNull(appSpecificElement);
     }
 
+    @Test
+    public void testStreamErrorXmlNotWellFormed() {
+        StreamError error = null;
+        final String xml =
+                // Usually the stream:stream element has more attributes (to, version, ...)
+                // We omit those, since they are not relevant for testing
+                "<stream:stream from='im.example.com' id='++TR84Sm6A3hnt3Q065SnAbbk3Y=' xmlns:stream='http://etherx.jabber.org/streams'>" +
+                        "<stream:error><xml-not-well-formed xmlns='urn:ietf:params:xml:ns:xmpp-streams'/></stream:error>" +
+                        "</stream:stream>";
+        try {
+            XmlPullParser parser = PacketParserUtils.getParserFor(xml, "error");
+            error = PacketParserUtils.parseStreamError(parser);
+        } catch (Exception e) {
+            fail(e.getMessage());
+        }
+        assertNotNull(error);
+        assertEquals(Condition.not_well_formed, error.getCondition());
+    }
 }

smack-experimental/src/main/java/org/jivesoftware/smackx/hoxt/provider/HttpOverXmppReqProvider.java

@@ -16,6 +16,8 @@
  */
 package org.jivesoftware.smackx.hoxt.provider;
 
+import org.jivesoftware.smack.util.ParserUtils;
+
 import org.jivesoftware.smackx.hoxt.packet.HttpMethod;
 import org.jivesoftware.smackx.hoxt.packet.HttpOverXmppReq;
 
@@ -47,13 +49,13 @@ public class HttpOverXmppReqProvider extends AbstractHttpOverXmppProvider<HttpOv
         String jingleStr = parser.getAttributeValue("", AbstractHttpOverXmppProvider.ELEMENT_JINGLE);
 
         if (sipubStr != null) {
-            builder.setSipub(Boolean.valueOf(sipubStr));
+            builder.setSipub(ParserUtils.parseXmlBoolean(sipubStr));
         }
         if (ibbStr != null) {
-            builder.setIbb(Boolean.valueOf(ibbStr));
+            builder.setIbb(ParserUtils.parseXmlBoolean(ibbStr));
         }
         if (jingleStr != null) {
-            builder.setJingle(Boolean.valueOf(jingleStr));
+            builder.setJingle(ParserUtils.parseXmlBoolean(jingleStr));
         }
 
         String maxChunkSize = parser.getAttributeValue("", ATTRIBUTE_MAX_CHUNK_SIZE);

smack-experimental/src/main/java/org/jivesoftware/smackx/iot/control/element/SetBoolData.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright © 2016 Florian Schmaus
+ * Copyright © 2016-2018 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,8 @@
  */
 package org.jivesoftware.smackx.iot.control.element;
 
+import org.jivesoftware.smack.util.ParserUtils;
+
 public class SetBoolData extends SetData {
 
     public SetBoolData(String name, boolean value) {
@@ -31,7 +33,7 @@ public class SetBoolData extends SetData {
 
     public Boolean getBooleanValue() {
         if (booleanCache != null) {
-            booleanCache = Boolean.valueOf(getValue());
+            booleanCache = ParserUtils.parseXmlBoolean(getValue());
         }
         return booleanCache;
     }

smack-experimental/src/main/java/org/jivesoftware/smackx/jingle_filetransfer/JingleFileTransferManager.java

@@ -32,7 +32,7 @@ public final class JingleFileTransferManager extends Manager {
         super(connection);
     }
 
-    public static JingleFileTransferManager getInstanceFor(XMPPConnection connection) {
+    public static synchronized JingleFileTransferManager getInstanceFor(XMPPConnection connection) {
         JingleFileTransferManager manager = INSTANCES.get(connection);
         if (manager == null) {
             manager = new JingleFileTransferManager(connection);

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/MamManager.java

@@ -114,8 +114,8 @@ import org.jxmpp.jid.Jid;
  * <pre>
  * {@code
  * MamQueryArgs mamQueryArgs = MamQueryArgs.builder()
- *                                 .withJid(jid)
+ *                                 .limitResultsToJid(jid)
- *                                 .setResultPageSize(10)
+ *                                 .setResultPageSizeTo(10)
  *                                 .queryLastPage()
  *                                 .build();
  * MamQuery mamQuery = mamManager.queryArchive(mamQueryArgs);
@@ -178,7 +178,9 @@ public final class MamManager extends Manager {
      * @param connection the XMPP connection to get the archive for.
      * @return the instance of MamManager.
      */
+    // CHECKSTYLE:OFF:RegexpSingleline
     public static MamManager getInstanceFor(XMPPConnection connection) {
+    // CHECKSTYLE:ON:RegexpSingleline
         return getInstanceFor(connection, (Jid) null);
     }
 
@@ -995,7 +997,7 @@ public final class MamManager extends Manager {
         public List<Message> pagePrevious(int count) throws NoResponseException, XMPPErrorException,
                         NotConnectedException, NotLoggedInException, InterruptedException {
             RSMSet previousResultRsmSet = getPreviousRsmSet();
-            RSMSet requestRsmSet = new RSMSet(count, previousResultRsmSet.getLast(), RSMSet.PageDirection.before);
+            RSMSet requestRsmSet = new RSMSet(count, previousResultRsmSet.getFirst(), RSMSet.PageDirection.before);
             return page(requestRsmSet);
         }
 

smack-experimental/src/main/java/org/jivesoftware/smackx/reference/ReferenceManager.java

@@ -51,7 +51,7 @@ public final class ReferenceManager extends Manager {
      * @param connection xmpp connection
      * @return reference manager instance
      */
-    public static ReferenceManager getInstanceFor(XMPPConnection connection) {
+    public static synchronized ReferenceManager getInstanceFor(XMPPConnection connection) {
         ReferenceManager manager = INSTANCES.get(connection);
         if (manager == null) {
             manager = new ReferenceManager(connection);

smack-experimental/src/main/java/org/jivesoftware/smackx/sid/StableUniqueStanzaIdManager.java

@@ -27,7 +27,6 @@ import org.jivesoftware.smack.XMPPConnectionRegistry;
 import org.jivesoftware.smack.filter.AndFilter;
 import org.jivesoftware.smack.filter.MessageTypeFilter;
 import org.jivesoftware.smack.filter.NotFilter;
-import org.jivesoftware.smack.filter.StanzaExtensionFilter;
 import org.jivesoftware.smack.filter.StanzaFilter;
 import org.jivesoftware.smack.filter.ToTypeFilter;
 import org.jivesoftware.smack.packet.Message;
@@ -46,13 +45,12 @@ public final class StableUniqueStanzaIdManager extends Manager {
             MessageTypeFilter.NORMAL_OR_CHAT_OR_HEADLINE,
             ToTypeFilter.ENTITY_FULL_OR_BARE_JID);
 
-    private static final StanzaFilter ORIGIN_ID_FILTER = new StanzaExtensionFilter(OriginIdElement.ELEMENT, NAMESPACE);
-
     // Listener for outgoing stanzas that adds origin-ids to outgoing stanzas.
-    private final StanzaListener stanzaListener = new StanzaListener() {
+    private static final StanzaListener ADD_ORIGIN_ID_INTERCEPTOR = new StanzaListener() {
         @Override
         public void processStanza(Stanza stanza) {
-            OriginIdElement.addOriginId((Message) stanza);
+            Message message = (Message) stanza;
+            OriginIdElement.addOriginId(message);
         }
     };
 
@@ -80,7 +78,7 @@ public final class StableUniqueStanzaIdManager extends Manager {
      * @param connection xmpp-connection
      * @return manager instance for the connection
      */
-    public static StableUniqueStanzaIdManager getInstanceFor(XMPPConnection connection) {
+    public static synchronized StableUniqueStanzaIdManager getInstanceFor(XMPPConnection connection) {
         StableUniqueStanzaIdManager manager = INSTANCES.get(connection);
         if (manager == null) {
             manager = new StableUniqueStanzaIdManager(connection);
@@ -95,7 +93,7 @@ public final class StableUniqueStanzaIdManager extends Manager {
     public synchronized void enable() {
         ServiceDiscoveryManager.getInstanceFor(connection()).addFeature(NAMESPACE);
         StanzaFilter filter = new AndFilter(OUTGOING_FILTER, new NotFilter(OUTGOING_FILTER));
-        connection().addStanzaInterceptor(stanzaListener, filter);
+        connection().addStanzaInterceptor(ADD_ORIGIN_ID_INTERCEPTOR, filter);
     }
 
     /**
@@ -103,7 +101,7 @@ public final class StableUniqueStanzaIdManager extends Manager {
      */
     public synchronized void disable() {
         ServiceDiscoveryManager.getInstanceFor(connection()).removeFeature(NAMESPACE);
-        connection().removeStanzaInterceptor(stanzaListener);
+        connection().removeStanzaInterceptor(ADD_ORIGIN_ID_INTERCEPTOR);
     }
 
     /**

smack-experimental/src/main/java/org/jivesoftware/smackx/sid/provider/OriginIdProvider.java

@@ -23,7 +23,11 @@ import org.xmlpull.v1.XmlPullParser;
 
 public class OriginIdProvider extends ExtensionElementProvider<OriginIdElement> {
 
-    public static final OriginIdProvider TEST_INSTANCE = new OriginIdProvider();
+    public static final OriginIdProvider INSTANCE = new OriginIdProvider();
+
+    // TODO: Remove in Smack 4.4.
+    @Deprecated
+    public static final OriginIdProvider TEST_INSTANCE = INSTANCE;
 
     @Override
     public OriginIdElement parse(XmlPullParser parser, int initialDepth) throws Exception {

smack-experimental/src/main/java/org/jivesoftware/smackx/sid/provider/StanzaIdProvider.java

@@ -23,7 +23,11 @@ import org.xmlpull.v1.XmlPullParser;
 
 public class StanzaIdProvider extends ExtensionElementProvider<StanzaIdElement> {
 
-    public static StanzaIdProvider TEST_INSTANCE = new StanzaIdProvider();
+    public static final StanzaIdProvider INSTANCE = new StanzaIdProvider();
+
+    // TODO: Remove in Smack 4.4.
+    @Deprecated
+    public static final StanzaIdProvider TEST_INSTANCE = INSTANCE;
 
     @Override
     public StanzaIdElement parse(XmlPullParser parser, int initialDepth) throws Exception {

smack-experimental/src/main/java/org/jivesoftware/smackx/spoiler/SpoilerManager.java

@@ -61,7 +61,7 @@ public final class SpoilerManager extends Manager {
      * @param connection xmpp connection
      * @return SpoilerManager
      */
-    public static SpoilerManager getInstanceFor(XMPPConnection connection) {
+    public static synchronized SpoilerManager getInstanceFor(XMPPConnection connection) {
         SpoilerManager manager = INSTANCES.get(connection);
         if (manager == null) {
             manager = new SpoilerManager(connection);

smack-experimental/src/test/java/org/jivesoftware/smackx/sid/StableUniqueStanzaIdTest.java

@@ -25,6 +25,7 @@ import static org.custommonkey.xmlunit.XMLAssert.assertXMLEqual;
 import org.jivesoftware.smack.packet.Message;
 import org.jivesoftware.smack.test.util.SmackTestSuite;
 import org.jivesoftware.smack.test.util.TestUtils;
+import org.jivesoftware.smack.util.PacketParserUtils;
 import org.jivesoftware.smackx.sid.element.OriginIdElement;
 import org.jivesoftware.smackx.sid.element.StanzaIdElement;
 import org.jivesoftware.smackx.sid.provider.OriginIdProvider;
@@ -42,7 +43,7 @@ public class StableUniqueStanzaIdTest extends SmackTestSuite {
         assertEquals("alice@wonderland.lit", element.getBy());
         assertXMLEqual(xml, element.toXML(null).toString());
 
-        StanzaIdElement parsed = StanzaIdProvider.TEST_INSTANCE.parse(TestUtils.getParser(xml));
+        StanzaIdElement parsed = StanzaIdProvider.INSTANCE.parse(TestUtils.getParser(xml));
         assertEquals(element.getId(), parsed.getId());
         assertEquals(element.getBy(), parsed.getBy());
     }
@@ -54,7 +55,7 @@ public class StableUniqueStanzaIdTest extends SmackTestSuite {
         assertEquals("de305d54-75b4-431b-adb2-eb6b9e546013", element.getId());
         assertXMLEqual(xml, element.toXML(null).toString());
 
-        OriginIdElement parsed = OriginIdProvider.TEST_INSTANCE.parse(TestUtils.getParser(xml));
+        OriginIdElement parsed = OriginIdProvider.INSTANCE.parse(TestUtils.getParser(xml));
         assertEquals(element.getId(), parsed.getId());
     }
 
@@ -81,4 +82,17 @@ public class StableUniqueStanzaIdTest extends SmackTestSuite {
         assertTrue(StanzaIdElement.hasStanzaId(message));
         assertEquals(stanzaId, StanzaIdElement.getStanzaId(message));
     }
+
+    @Test
+    public void testMultipleUssidExtensions() throws Exception {
+        String message = "<message xmlns='jabber:client' from='e4aec989-3e20-4846-83bf-f50df89b5d07@muclight.example.com/user1@example.com' to='user1@example.com' id='6b71fe3a-3cb2-489c-9c8e-b6879761d15e' type='groupchat'>" +
+                          "<body>Test message</body>" +
+                          "<markable xmlns='urn:xmpp:chat-markers:0'/>" +
+                          "<stanza-id by='e4aec989-3e20-4846-83bf-f50df89b5d07@muclight.example.com' id='B0KK24ETVC81' xmlns='urn:xmpp:sid:0'/>" +
+                          "<stanza-id by='user1@example.com' id='B0KK24EV89G1' xmlns='urn:xmpp:sid:0'/>" +
+                        "</message>";
+        Message messageStanza = PacketParserUtils.parseStanza(message);
+
+        assertTrue(StanzaIdElement.hasStanzaId(messageStanza));
+    }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/bookmarks/Bookmarks.java

@@ -269,12 +269,12 @@ public class Bookmarks implements PrivateData {
 
     private static BookmarkedConference getConferenceStorage(XmlPullParser parser) throws XmlPullParserException, IOException {
         String name = parser.getAttributeValue("", "name");
-        String autojoin = parser.getAttributeValue("", "autojoin");
+        boolean autojoin = ParserUtils.getBooleanAttribute(parser, "autojoin", false);
         EntityBareJid jid = ParserUtils.getBareJidAttribute(parser);
 
         BookmarkedConference conf = new BookmarkedConference(jid);
         conf.setName(name);
-        conf.setAutoJoin(Boolean.valueOf(autojoin));
+        conf.setAutoJoin(autojoin);
 
         // Check for nickname
         boolean done = false;

smack-extensions/src/main/java/org/jivesoftware/smackx/bytestreams/socks5/Socks5Proxy.java

@@ -211,6 +211,7 @@ public final class Socks5Proxy {
             if (this.serverSocket != null) {
                 this.serverThread = new Thread(this.serverProcess);
                 this.serverThread.setName("Smack Local SOCKS5 Proxy");
+                this.serverThread.setDaemon(true);
                 this.serverThread.start();
             }
         }

smack-extensions/src/main/java/org/jivesoftware/smackx/disco/ServiceDiscoveryManager.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2003-2007 Jive Software, 2018 Florian Schmaus.
+ * Copyright 2003-2007 Jive Software, 2018-2019 Florian Schmaus.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -227,7 +227,7 @@ public final class ServiceDiscoveryManager extends Manager {
     /**
      * Returns the type of client that will be returned when asked for the client identity in a
      * disco request. The valid types are defined by the category client. Follow this link to learn
-     * the possible types: <a href="http://xmpp.org/registrar/disco-categories.html#client">Jabber::Registrar</a>.
+     * the possible types: <a href="https://xmpp.org/registrar/disco-categories.html">XMPP Registry for Service Discovery Identities</a>
      *
      * @return the type of client that will be returned when asked for the client identity in a
      *          disco request.
@@ -271,8 +271,8 @@ public final class ServiceDiscoveryManager extends Manager {
      */
     public Set<DiscoverInfo.Identity> getIdentities() {
         Set<Identity> res = new HashSet<>(identities);
-        // Add the default identity that must exist
+        // Add the main identity that must exist
-        res.add(defaultIdentity);
+        res.add(identity);
         return Collections.unmodifiableSet(res);
     }
 

smack-extensions/src/main/java/org/jivesoftware/smackx/disco/packet/DiscoverInfo.java

@@ -263,7 +263,7 @@ public class DiscoverInfo extends IQ implements TypedCloneable<DiscoverInfo> {
      * Represents the identity of a given XMPP entity. An entity may have many identities but all
      * the identities SHOULD have the same name.<p>
      *
-     * Refer to <a href="http://www.jabber.org/registrar/disco-categories.html">Jabber::Registrar</a>
+     * Refer to <a href="https://xmpp.org/registrar/disco-categories.html">XMPP Registry for Service Discovery Identities</a>
      * in order to get the official registry of values for the <i>category</i> and <i>type</i>
      * attributes.
      *
@@ -327,7 +327,7 @@ public class DiscoverInfo extends IQ implements TypedCloneable<DiscoverInfo> {
 
         /**
          * Returns the entity's category. To get the official registry of values for the
-         * 'category' attribute refer to <a href="http://www.jabber.org/registrar/disco-categories.html">Jabber::Registrar</a>
+         * 'category' attribute refer to <a href="https://xmpp.org/registrar/disco-categories.html">XMPP Registry for Service Discovery Identities</a>.
          *
          * @return the entity's category.
          */
@@ -346,7 +346,7 @@ public class DiscoverInfo extends IQ implements TypedCloneable<DiscoverInfo> {
 
         /**
          * Returns the entity's type. To get the official registry of values for the
-         * 'type' attribute refer to <a href="http://www.jabber.org/registrar/disco-categories.html">Jabber::Registrar</a>
+         * 'type' attribute refer to <a href="https://xmpp.org/registrar/disco-categories.html">XMPP Registry for Service Discovery Identities</a>.
          *
          * @return the entity's type.
          */

smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/JingleTransportMethodManager.java

@@ -48,7 +48,7 @@ public final class JingleTransportMethodManager extends Manager {
         super(connection);
     }
 
-    public static JingleTransportMethodManager getInstanceFor(XMPPConnection connection) {
+    public static synchronized JingleTransportMethodManager getInstanceFor(XMPPConnection connection) {
         JingleTransportMethodManager manager = INSTANCES.get(connection);
         if (manager == null) {
             manager = new JingleTransportMethodManager(connection);

smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/jingle_ibb/JingleIBBTransportManager.java

@@ -38,7 +38,7 @@ public final class JingleIBBTransportManager extends JingleTransportManager<Jing
         JingleContentProviderManager.addJingleContentTransportProvider(getNamespace(), new JingleIBBTransportProvider());
     }
 
-    public static JingleIBBTransportManager getInstanceFor(XMPPConnection connection) {
+    public static synchronized JingleIBBTransportManager getInstanceFor(XMPPConnection connection) {
         JingleIBBTransportManager manager = INSTANCES.get(connection);
         if (manager == null) {
             manager = new JingleIBBTransportManager(connection);

smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/jingle_s5b/JingleS5BTransportManager.java

@@ -63,7 +63,7 @@ public final class JingleS5BTransportManager extends JingleTransportManager<Jing
         JingleContentProviderManager.addJingleContentTransportProvider(getNamespace(), new JingleS5BTransportProvider());
     }
 
-    public static JingleS5BTransportManager getInstanceFor(XMPPConnection connection) {
+    public static synchronized JingleS5BTransportManager getInstanceFor(XMPPConnection connection) {
         JingleS5BTransportManager manager = INSTANCES.get(connection);
         if (manager == null) {
             manager = new JingleS5BTransportManager(connection);

smack-extensions/src/main/java/org/jivesoftware/smackx/jiveproperties/provider/JivePropertiesExtensionProvider.java

@@ -92,7 +92,9 @@ public class JivePropertiesExtensionProvider extends ExtensionElementProvider<Ji
                                 value = Double.valueOf(valueText);
                             }
                             else if ("boolean".equals(type)) {
+                                // CHECKSTYLE:OFF
                                 value = Boolean.valueOf(valueText);
+                                // CHECKSTYLE:ON
                             }
                             else if ("string".equals(type)) {
                                 value = valueText;

smack-extensions/src/main/java/org/jivesoftware/smackx/muc/MultiUserChat.java

@@ -205,7 +205,6 @@ public class MultiUserChat {
                 final Presence presence = (Presence) packet;
                 final EntityFullJid from = presence.getFrom().asEntityFullJidIfPossible();
                 if (from == null) {
-                    LOGGER.warning("Presence not from a full JID: " + presence.getFrom());
                     return;
                 }
                 final EntityFullJid myRoomJID = myRoomJid;
@@ -341,8 +340,9 @@ public class MultiUserChat {
 
         // Setup the messageListeners and presenceListeners *before* the join presence is send.
         connection.addSyncStanzaListener(messageListener, fromRoomGroupchatFilter);
-        connection.addSyncStanzaListener(presenceListener, new AndFilter(fromRoomFilter,
+        StanzaFilter presenceFromRoomFilter = new AndFilter(fromRoomFilter,
-                        StanzaTypeFilter.PRESENCE));
+                        StanzaTypeFilter.PRESENCE);
+        connection.addSyncStanzaListener(presenceListener, presenceFromRoomFilter);
         // @formatter:off
         connection.addSyncStanzaListener(subjectListener,
                         new AndFilter(fromRoomFilter,
@@ -371,15 +371,27 @@ public class MultiUserChat {
                         )
                     );
         // @formatter:on
+        StanzaCollector presenceStanzaCollector = null;
         Presence presence;
         try {
-            presence = connection.createStanzaCollectorAndSend(responseFilter, joinPresence).nextResultOrThrow(conf.getTimeout());
+            // This stanza collector will collect the final self presence from the MUC, which also signals that we have successful entered the MUC.
+            StanzaCollector selfPresenceCollector = connection.createStanzaCollectorAndSend(responseFilter, joinPresence);
+            StanzaCollector.Configuration presenceStanzaCollectorConfguration = StanzaCollector.newConfiguration().setCollectorToReset(
+                            selfPresenceCollector).setStanzaFilter(presenceFromRoomFilter);
+            // This stanza collector is used to reset the timeout of the selfPresenceCollector.
+            presenceStanzaCollector = connection.createStanzaCollector(presenceStanzaCollectorConfguration);
+            presence = selfPresenceCollector.nextResultOrThrow(conf.getTimeout());
         }
         catch (NotConnectedException | InterruptedException | NoResponseException | XMPPErrorException e) {
             // Ensure that all callbacks are removed if there is an exception
             removeConnectionCallbacks();
             throw e;
         }
+        finally {
+            if (presenceStanzaCollector != null) {
+                presenceStanzaCollector.cancel();
+            }
+        }
 
         // This presence must be send from a full JID. We use the resourcepart of this JID as nick, since the room may
         // performed roomnick rewriting
@@ -735,7 +747,12 @@ public class MultiUserChat {
         // If we've already joined the room, leave it before joining under a new
         // nickname.
         if (joined) {
-            leave();
+            try {
+                leaveSync();
+            }
+            catch (XMPPErrorException | NoResponseException | MucNotJoinedException e) {
+                LOGGER.log(Level.WARNING, "Could not leave MUC prior joining, assuming we are not joined", e);
+            }
         }
         enter(mucEnterConfiguration);
     }
@@ -776,6 +793,50 @@ public class MultiUserChat {
         connection.sendStanza(leavePresence);
     }
 
+    /**
+     * Leave the chat room.
+     *
+     * @return the leave presence as reflected by the MUC.
+     * @throws NotConnectedException
+     * @throws InterruptedException
+     * @throws XMPPErrorException
+     * @throws NoResponseException
+     * @throws MucNotJoinedException
+     */
+    public synchronized Presence leaveSync()
+                    throws NotConnectedException, InterruptedException, NoResponseException, XMPPErrorException, MucNotJoinedException {
+        //  Note that this method is intentionally not guarded by
+        // "if  (!joined) return" because it should be always be possible to leave the room in case the instance's
+        // state does not reflect the actual state.
+
+        // Reset occupant information first so that we are assume that we left the room even if sendStanza() would
+        // throw.
+        userHasLeft();
+
+        final EntityFullJid myRoomJid = this.myRoomJid;
+        if (myRoomJid == null) {
+            throw new MucNotJoinedException(this);
+        }
+
+        // We leave a room by sending a presence packet where the "to"
+        // field is in the form "roomName@service/nickname"
+        Presence leavePresence = new Presence(Presence.Type.unavailable);
+        leavePresence.setTo(myRoomJid);
+
+        StanzaFilter reflectedLeavePresenceFilter = new AndFilter(
+                        StanzaTypeFilter.PRESENCE,
+                        new StanzaIdFilter(leavePresence),
+                        new OrFilter(
+                                        new AndFilter(FromMatchesFilter.createFull(myRoomJid), PresenceTypeFilter.UNAVAILABLE, MUCUserStatusCodeFilter.STATUS_110_PRESENCE_TO_SELF),
+                                        new AndFilter(fromRoomFilter, PresenceTypeFilter.ERROR)
+                                    )
+                                );
+
+        Presence reflectedLeavePresence = connection.createStanzaCollectorAndSend(reflectedLeavePresenceFilter, leavePresence).nextResultOrThrow();
+
+        return reflectedLeavePresence;
+    }
+
     /**
      * Get a {@link MucConfigFormManager} to configure this room.
      * <p>

smack-extensions/src/main/java/org/jivesoftware/smackx/muc/MultiUserChatManager.java

@@ -19,6 +19,7 @@ package org.jivesoftware.smackx.muc;
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -392,19 +393,46 @@ public final class MultiUserChatManager extends Manager {
      * @throws NotConnectedException
      * @throws InterruptedException
      * @throws NotAMucServiceException
+     * @deprecated use {@link #getRoomsHostedBy(DomainBareJid)} instead.
      */
+    @Deprecated
+    // TODO: Remove in Smack 4.4.
     public List<HostedRoom> getHostedRooms(DomainBareJid serviceName) throws NoResponseException, XMPPErrorException,
                     NotConnectedException, InterruptedException, NotAMucServiceException {
+        Map<EntityBareJid, HostedRoom> hostedRooms = getRoomsHostedBy(serviceName);
+        return new ArrayList<>(hostedRooms.values());
+    }
+
+    /**
+     * Returns a Map of HostedRooms where each HostedRoom has the XMPP address of the room and the room's name.
+     * Once discovered the rooms hosted by a chat service it is possible to discover more detailed room information or
+     * join the room.
+     *
+     * @param serviceName the service that is hosting the rooms to discover.
+     * @return a map from the room's address to its HostedRoom information.
+     * @throws XMPPErrorException
+     * @throws NoResponseException
+     * @throws NotConnectedException
+     * @throws InterruptedException
+     * @throws NotAMucServiceException
+     * @since 4.3.1
+     */
+    public Map<EntityBareJid, HostedRoom> getRoomsHostedBy(DomainBareJid serviceName) throws NoResponseException, XMPPErrorException,
+                    NotConnectedException, InterruptedException, NotAMucServiceException {
         if (!providesMucService(serviceName)) {
             throw new NotAMucServiceException(serviceName);
         }
         ServiceDiscoveryManager discoManager = ServiceDiscoveryManager.getInstanceFor(connection());
         DiscoverItems discoverItems = discoManager.discoverItems(serviceName);
         List<DiscoverItems.Item> items = discoverItems.getItems();
-        List<HostedRoom> answer = new ArrayList<HostedRoom>(items.size());
+
+        Map<EntityBareJid, HostedRoom> answer = new HashMap<>(items.size());
         for (DiscoverItems.Item item : items) {
-            answer.add(new HostedRoom(item));
+            HostedRoom hostedRoom = new HostedRoom(item);
+            HostedRoom previousRoom = answer.put(hostedRoom.getJid(), hostedRoom);
+            assert previousRoom == null;
         }
+
         return answer;
     }
 

smack-extensions/src/main/java/org/jivesoftware/smackx/muc/RoomInfo.java

@@ -207,7 +207,8 @@ public class RoomInfo {
 
             FormField subjectmodField = form.getField("muc#roominfo_subjectmod");
             if (subjectmodField != null && !subjectmodField.getValues().isEmpty()) {
-                subjectmod = Boolean.valueOf(subjectmodField.getFirstValue());
+                String firstValue = subjectmodField.getFirstValue();
+                subjectmod = ("true".equals(firstValue) || "1".equals(firstValue));
             }
 
             FormField urlField = form.getField("muc#roominfo_logs");

smack-extensions/src/main/java/org/jivesoftware/smackx/receipts/DeliveryReceiptManager.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2013-2014 Georg Lukas, 2015 Florian Schmaus
+ * Copyright 2013-2014 Georg Lukas, 2015-2019 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -74,8 +74,16 @@ import org.jxmpp.jid.Jid;
  */
 public final class DeliveryReceiptManager extends Manager {
 
-    private static final StanzaFilter MESSAGES_WITH_DELIVERY_RECEIPT_REQUEST = new AndFilter(StanzaTypeFilter.MESSAGE,
+    /**
-                    new StanzaExtensionFilter(new DeliveryReceiptRequest()));
+     * Filters all non-error messages with receipt requests.
+     * See <a href="https://xmpp.org/extensions/xep-0184.html#when">XEP-0184 § 5.</a> "A sender could request receipts
+     * on any non-error content message (chat, groupchat, headline, or normal)…"
+     */
+    private static final StanzaFilter NON_ERROR_GROUPCHAT_MESSAGES_WITH_DELIVERY_RECEIPT_REQUEST = new AndFilter(
+            StanzaTypeFilter.MESSAGE,
+            new StanzaExtensionFilter(new DeliveryReceiptRequest()),
+            new NotFilter(MessageTypeFilter.ERROR));
+
     private static final StanzaFilter MESSAGES_WITH_DELIVERY_RECEIPT = new AndFilter(StanzaTypeFilter.MESSAGE,
                     new StanzaExtensionFilter(DeliveryReceipt.ELEMENT, DeliveryReceipt.NAMESPACE));
 
@@ -175,7 +183,7 @@ public final class DeliveryReceiptManager extends Manager {
                 }
                 connection.sendStanza(ack);
             }
-        }, MESSAGES_WITH_DELIVERY_RECEIPT_REQUEST);
+        }, NON_ERROR_GROUPCHAT_MESSAGES_WITH_DELIVERY_RECEIPT_REQUEST);
     }
 
     /**

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/FormField.java

@@ -261,12 +261,14 @@ public class FormField implements NamedElement {
      */
     public String getFirstValue() {
         CharSequence firstValue;
+
         synchronized (values) {
+            if (values.isEmpty()) {
+                return null;
+            }
             firstValue = values.get(0);
         }
-        if (firstValue == null) {
+
-            return null;
-        }
         return firstValue.toString();
     }
 

smack-im/src/main/java/org/jivesoftware/smack/roster/Roster.java

@@ -951,8 +951,7 @@ public final class Roster extends Manager {
             // This is used in case no available presence is found
             Presence unavailable = null;
 
-            for (Resourcepart resource : userPresences.keySet()) {
+            for (Presence p : userPresences.values()) {
-                Presence p = userPresences.get(resource);
                 if (!p.isAvailable()) {
                     unavailable = p;
                     continue;
@@ -1472,7 +1471,29 @@ public final class Roster extends Manager {
             final Presence presence = (Presence) packet;
             final Jid from = presence.getFrom();
 
-            final BareJid key = from != null ? from.asBareJid() : null;
+            final BareJid key;
+            if (from != null) {
+                key = from.asBareJid();
+            } else {
+                XMPPConnection connection = connection();
+                if (connection == null) {
+                    LOGGER.finest("Connection was null while trying to handle exotic presence stanza: " + presence);
+                    return;
+                }
+                // Assume the presence come "from the users account on the server" since no from was set (RFC 6120 §
+                // 8.1.2.1 4.). Note that getUser() may return null, but should never return null in this case as where
+                // connected.
+                EntityFullJid myJid = connection.getUser();
+                if (myJid == null) {
+                    LOGGER.info(
+                            "Connection had no local address in Roster's presence listener."
+                            + " Possibly we received a presence without from before being authenticated."
+                            + " Presence: " + presence);
+                    return;
+                }
+                LOGGER.info("Exotic presence stanza without from received: " + presence);
+                key = myJid.asBareJid();
+            }
 
             asyncButOrdered.performAsyncButOrdered(key, new Runnable() {
                 @Override

smack-integration-test/src/main/java/org/jivesoftware/smackx/muc/MultiUserChatIntegrationTest.java

@@ -16,6 +16,9 @@
  */
 package org.jivesoftware.smackx.muc;
 
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
 import java.util.List;
 
 import org.jivesoftware.smack.MessageListener;
@@ -23,8 +26,12 @@ import org.jivesoftware.smack.SmackException.NoResponseException;
 import org.jivesoftware.smack.SmackException.NotConnectedException;
 import org.jivesoftware.smack.XMPPException.XMPPErrorException;
 import org.jivesoftware.smack.packet.Message;
+import org.jivesoftware.smack.packet.Presence;
 import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smackx.muc.MultiUserChat.MucCreateConfigFormHandle;
+import org.jivesoftware.smackx.muc.MultiUserChatException.MucNotJoinedException;
+import org.jivesoftware.smackx.muc.MultiUserChatException.NotAMucServiceException;
+import org.jivesoftware.smackx.muc.packet.MUCUser;
 
 import org.igniterealtime.smack.inttest.AbstractSmackIntegrationTest;
 import org.igniterealtime.smack.inttest.SmackIntegrationTest;
@@ -36,6 +43,7 @@ import org.jxmpp.jid.EntityBareJid;
 import org.jxmpp.jid.impl.JidCreate;
 import org.jxmpp.jid.parts.Localpart;
 import org.jxmpp.jid.parts.Resourcepart;
+import org.jxmpp.stringprep.XmppStringprepException;
 
 public class MultiUserChatIntegrationTest extends AbstractSmackIntegrationTest {
 
@@ -61,6 +69,24 @@ public class MultiUserChatIntegrationTest extends AbstractSmackIntegrationTest {
         }
     }
 
+    @SmackIntegrationTest
+    public void mucJoinLeaveTest() throws XmppStringprepException, NotAMucServiceException, NoResponseException,
+            XMPPErrorException, NotConnectedException, InterruptedException, MucNotJoinedException {
+        EntityBareJid mucAddress = JidCreate.entityBareFrom(Localpart.from("smack-inttest-join-leave-" + randomString),
+                mucService.getDomain());
+
+        MultiUserChat muc = mucManagerOne.getMultiUserChat(mucAddress);
+
+        muc.join(Resourcepart.from("nick-one"));
+
+        Presence reflectedLeavePresence = muc.leaveSync();
+
+        MUCUser mucUser = MUCUser.from(reflectedLeavePresence);
+        assertNotNull(mucUser);
+
+        assertTrue(mucUser.getStatus().contains(MUCUser.Status.PRESENCE_TO_SELF_110));
+    }
+
     @SmackIntegrationTest
     public void mucTest() throws Exception {
         EntityBareJid mucAddress = JidCreate.entityBareFrom(Localpart.from("smack-inttest-" + randomString), mucService.getDomain());

smack-jingle-old/src/main/java/org/jivesoftware/smackx/jingleold/JingleSession.java

@@ -620,7 +620,7 @@ public class JingleSession extends JingleNegotiator implements MediaReceivedList
      *            A XMPP connection
      * @return a Jingle session
      */
-    public static JingleSession getInstanceFor(XMPPConnection con) {
+    public static synchronized JingleSession getInstanceFor(XMPPConnection con) {
         if (con == null) {
             throw new IllegalArgumentException("XMPPConnection cannot be null");
         }

smack-legacy/src/main/java/org/jivesoftware/smackx/workgroup/settings/WorkgroupProperties.java

@@ -104,7 +104,9 @@ public class WorkgroupProperties extends IQ {
             while (!done) {
                 int eventType = parser.next();
                 if ((eventType == XmlPullParser.START_TAG) && ("authRequired".equals(parser.getName()))) {
+                    // CHECKSTYLE:OFF
                     props.setAuthRequired(Boolean.valueOf(parser.nextText()).booleanValue());
+                    // CHECKSTYLE:ON
                 }
                 else if ((eventType == XmlPullParser.START_TAG) && ("email".equals(parser.getName()))) {
                     props.setEmail(parser.nextText());

smack-resolver-javax/src/main/java/org/jivesoftware/smack/util/dns/javax/JavaxResolver.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2013-2018 Florian Schmaus
+ * Copyright 2013-2019 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -41,6 +41,7 @@ import org.minidns.dnsname.DnsName;
 
 /**
  * A DNS resolver (mostly for SRV records), which makes use of the API provided in the javax.* namespace.
+ * Note that using JavaxResovler requires applications using newer Java versions (at least 11) to declare a dependency on the "sun.jdk" module.
  *
  * @author Florian Schmaus
  *
@@ -55,8 +56,8 @@ public class JavaxResolver extends DNSResolver implements SmackInitializer {
             Hashtable<String, String> env = new Hashtable<>();
             env.put("java.naming.factory.initial", "com.sun.jndi.dns.DnsContextFactory");
             dirContext = new InitialDirContext(env);
-        } catch (Exception e) {
+        } catch (NamingException e) {
-            // Ignore.
+            LOGGER.log(Level.SEVERE, "Could not construct InitialDirContext", e);
         }
 
         // Try to set this DNS resolver as primary one

smack-tcp/src/main/java/org/jivesoftware/smack/sm/StreamManagementException.java

@@ -16,10 +16,13 @@
  */
 package org.jivesoftware.smack.sm;
 
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.concurrent.BlockingQueue;
 
 import org.jivesoftware.smack.SmackException;
+import org.jivesoftware.smack.packet.Element;
 import org.jivesoftware.smack.packet.Stanza;
 
 public abstract class StreamManagementException extends SmackException {
@@ -110,5 +113,56 @@ public abstract class StreamManagementException extends SmackException {
             return ackedStanzas;
         }
     }
+
+    public static final class UnacknowledgedQueueFullException extends StreamManagementException {
+
+        /**
+         *
+         */
+        private static final long serialVersionUID = 1L;
+
+        private final int overflowElementNum;
+        private final int droppedElements;
+        private final List<Element> elements;
+        private final List<Stanza> unacknowledgesStanzas;
+
+        private UnacknowledgedQueueFullException(String message, int overflowElementNum, int droppedElements, List<Element> elements,
+                List<Stanza> unacknowledgesStanzas) {
+            super(message);
+            this.overflowElementNum = overflowElementNum;
+            this.droppedElements = droppedElements;
+            this.elements = elements;
+            this.unacknowledgesStanzas = unacknowledgesStanzas;
+        }
+
+        public int getOverflowElementNum() {
+            return overflowElementNum;
+        }
+
+        public int getDroppedElements() {
+            return droppedElements;
+        }
+
+        public List<Element> getElements() {
+            return elements;
+        }
+
+        public List<Stanza> getUnacknowledgesStanzas() {
+            return unacknowledgesStanzas;
+        }
+
+        public static UnacknowledgedQueueFullException newWith(int overflowElementNum, List<Element> elements,
+                BlockingQueue<Stanza> unacknowledgedStanzas) {
+            final int unacknowledgesStanzasQueueSize = unacknowledgedStanzas.size();
+            List<Stanza> localUnacknowledgesStanzas = new ArrayList<>(unacknowledgesStanzasQueueSize);
+            localUnacknowledgesStanzas.addAll(unacknowledgedStanzas);
+            int droppedElements = elements.size() - overflowElementNum - 1;
+
+            String message = "The queue size " + unacknowledgesStanzasQueueSize + " is not able to fit another "
+                    + droppedElements + " potential stanzas type top-level stream-elements.";
+            return new UnacknowledgedQueueFullException(message, overflowElementNum, droppedElements, elements,
+                    localUnacknowledgesStanzas);
+        }
+    }
 }
 

smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XMPPTCPConnection.java

@@ -51,6 +51,7 @@ import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Level;
@@ -83,6 +84,8 @@ import org.jivesoftware.smack.SmackException.NoResponseException;
 import org.jivesoftware.smack.SmackException.NotConnectedException;
 import org.jivesoftware.smack.SmackException.NotLoggedInException;
 import org.jivesoftware.smack.SmackException.SecurityRequiredByServerException;
+import org.jivesoftware.smack.SmackException.SmackWrappedException;
+import org.jivesoftware.smack.SmackFuture;
 import org.jivesoftware.smack.StanzaListener;
 import org.jivesoftware.smack.SynchronizationPoint;
 import org.jivesoftware.smack.XMPPConnection;
@@ -165,15 +168,17 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
 
     private SSLSocket secureSocket;
 
-    /**
+    private final Semaphore readerWriterSemaphore = new Semaphore(2);
-     * Protected access level because of unit test purposes
-     */
-    protected PacketWriter packetWriter;
 
     /**
      * Protected access level because of unit test purposes
      */
-    protected PacketReader packetReader;
+    protected final PacketWriter packetWriter = new PacketWriter();
+
+    /**
+     * Protected access level because of unit test purposes
+     */
+    protected final PacketReader packetReader = new PacketReader();
 
     private final SynchronizationPoint<Exception> initialOpenStreamSend = new SynchronizationPoint<>(
                     this, "initial open stream element send to server");
@@ -278,6 +283,15 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
      */
     private final Collection<StanzaListener> stanzaAcknowledgedListeners = new ConcurrentLinkedQueue<>();
 
+    /**
+     * These listeners are invoked for every stanza that got dropped.
+     * <p>
+     * We use a {@link ConcurrentLinkedQueue} here in order to allow the listeners to remove
+     * themselves after they have been invoked.
+     * </p>
+     */
+    private final Collection<StanzaListener> stanzaDroppedListeners = new ConcurrentLinkedQueue<>();
+
     /**
      * This listeners are invoked for a acknowledged stanza that has the given stanza ID. They will
      * only be invoked once and automatically removed after that.
@@ -387,6 +401,11 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
         SSLSession sslSession = secureSocket != null ? secureSocket.getSession() : null;
         saslAuthentication.authenticate(username, password, config.getAuthzid(), sslSession);
 
+        // Wait for stream features after the authentication.
+        // TODO: The name of this synchronization point "maybeCompressFeaturesReceived" is not perfect. It should be
+        // renamed to "streamFeaturesAfterAuthenticationReceived".
+        maybeCompressFeaturesReceived.checkIfSuccessOrWait();
+
         // If compression is enabled then request the server to use stream compression. XEP-170
         // recommends to perform stream compression before resource binding.
         maybeEnableCompression();
@@ -437,9 +456,24 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
                 }
             }
         }
-        // (Re-)send the stanzas *after* we tried to enable SM
+        // Inform client about failed resumption if possible, resend stanzas otherwise
-        for (Stanza stanza : previouslyUnackedStanzas) {
+        // Process the stanzas synchronously so a client can re-queue them for transmission
-            sendStanzaInternal(stanza);
+        // before it is informed about connection success
+        if (!stanzaDroppedListeners.isEmpty()) {
+            for (Stanza stanza : previouslyUnackedStanzas) {
+                for (StanzaListener listener : stanzaDroppedListeners) {
+                    try {
+                        listener.processStanza(stanza);
+                    }
+                    catch (InterruptedException | NotConnectedException | NotLoggedInException e) {
+                        LOGGER.log(Level.FINER, "StanzaDroppedListener received exception", e);
+                    }
+                }
+            }
+        } else {
+            for (Stanza stanza : previouslyUnackedStanzas) {
+                sendStanzaInternal(stanza);
+            }
         }
 
         afterSuccessfulLogin(false);
@@ -468,24 +502,16 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
         shutdown(false);
     }
 
-    /**
+    @Override
-     * Performs an unclean disconnect and shutdown of the connection. Does not send a closing stream stanza.
-     */
     public synchronized void instantShutdown() {
         shutdown(true);
     }
 
     private void shutdown(boolean instant) {
-        if (disconnectedButResumeable) {
-            return;
-        }
-
         // First shutdown the writer, this will result in a closing stream element getting send to
         // the server
-        if (packetWriter != null) {
+        LOGGER.finer("PacketWriter shutdown()");
-            LOGGER.finer("PacketWriter shutdown()");
+        packetWriter.shutdown(instant);
-            packetWriter.shutdown(instant);
-        }
         LOGGER.finer("PacketWriter has been shut down");
 
         if (!instant) {
@@ -500,19 +526,29 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
             }
         }
 
-        if (packetReader != null) {
+        LOGGER.finer("PacketReader shutdown()");
-            LOGGER.finer("PacketReader shutdown()");
+        packetReader.shutdown();
-                packetReader.shutdown();
-        }
         LOGGER.finer("PacketReader has been shut down");
 
-        try {
+        final Socket socket = this.socket;
+        if (socket != null && socket.isConnected()) {
+            try {
                 socket.close();
-        } catch (Exception e) {
+            } catch (Exception e) {
                 LOGGER.log(Level.WARNING, "shutdown", e);
+            }
         }
 
         setWasAuthenticated();
+
+        // Wait for reader and writer threads to be terminated.
+        readerWriterSemaphore.acquireUninterruptibly(2);
+        readerWriterSemaphore.release(2);
+
+        if (disconnectedButResumeable) {
+            return;
+        }
+
         // If we are able to resume the stream, then don't set
         // connected/authenticated/usingTLS to false since we like behave like we are still
         // connected (e.g. sendStanza should not throw a NotConnectedException).
@@ -523,6 +559,8 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
             // Reset the stream management session id to null, since if the stream is cleanly closed, i.e. sending a closing
             // stream tag, there is no longer a stream to resume.
             smSessionId = null;
+            // Note that we deliberately do not reset authenticatedConnectionInitiallyEstablishedTimestamp here, so that the
+            // information is available in the connectionClosedOnError() listeners.
         }
         authenticated = false;
         connected = false;
@@ -530,6 +568,12 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
         reader = null;
         writer = null;
 
+        initState();
+    }
+
+    @Override
+    protected void initState() {
+        super.initState();
         maybeCompressFeaturesReceived.init();
         compressSyncPoint.init();
         smResumedSyncPoint.init();
@@ -555,7 +599,7 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
         }
     }
 
-    private void connectUsingConfiguration() throws ConnectionException, IOException {
+    private void connectUsingConfiguration() throws ConnectionException, IOException, InterruptedException {
         List<HostAddress> failedAddresses = populateHostAddresses();
         SocketFactory socketFactory = config.getSocketFactory();
         ProxyInfo proxyInfo = config.getProxyInfo();
@@ -574,14 +618,16 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
                 innerloop: while (inetAddresses.hasNext()) {
                     // Create a *new* Socket before every connection attempt, i.e. connect() call, since Sockets are not
                     // re-usable after a failed connection attempt. See also SMACK-724.
-                    socket = socketFactory.createSocket();
+                    SmackFuture.SocketFuture socketFuture = new SmackFuture.SocketFuture(socketFactory);
 
                     final InetAddress inetAddress = inetAddresses.next();
-                    final String inetAddressAndPort = inetAddress + " at port " + port;
+                    final InetSocketAddress inetSocketAddress = new InetSocketAddress(inetAddress, port);
-                    LOGGER.finer("Trying to establish TCP connection to " + inetAddressAndPort);
+                    LOGGER.finer("Trying to establish TCP connection to " + inetSocketAddress);
+                    socketFuture.connectAsync(inetSocketAddress, timeout);
+
                     try {
-                        socket.connect(new InetSocketAddress(inetAddress, port), timeout);
+                        socket = socketFuture.getOrThrow();
-                    } catch (Exception e) {
+                    } catch (IOException e) {
                         hostAddress.setException(inetAddress, e);
                         if (inetAddresses.hasNext()) {
                             continue innerloop;
@@ -589,7 +635,7 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
                             break innerloop;
                         }
                     }
-                    LOGGER.finer("Established TCP connection to " + inetAddressAndPort);
+                    LOGGER.finer("Established TCP connection to " + inetSocketAddress);
                     // We found a host to connect to, return here
                     this.host = host;
                     this.port = port;
@@ -605,6 +651,7 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
                     proxyInfo.getProxySocketConnection().connect(socket, host, port, timeout);
                 } catch (IOException e) {
                     hostAddress.setException(e);
+                    failedAddresses.add(hostAddress);
                     continue;
                 }
                 LOGGER.finer("Established TCP connection to " + hostAndPort);
@@ -627,18 +674,23 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
      * @throws XMPPException if establishing a connection to the server fails.
      * @throws SmackException if the server fails to respond back or if there is anther error.
      * @throws IOException
+     * @throws InterruptedException
      */
-    private void initConnection() throws IOException {
+    private void initConnection() throws IOException, InterruptedException {
-        boolean isFirstInitialization = packetReader == null || packetWriter == null;
         compressionHandler = null;
 
         // Set the reader and writer instance variables
         initReaderAndWriter();
 
-        if (isFirstInitialization) {
+        int availableReaderWriterSemaphorePermits = readerWriterSemaphore.availablePermits();
-            packetWriter = new PacketWriter();
+        if (availableReaderWriterSemaphorePermits < 2) {
-            packetReader = new PacketReader();
+            Object[] logObjects = new Object[] {
+                            this,
+                            availableReaderWriterSemaphorePermits,
+            };
+            LOGGER.log(Level.FINE, "Not every reader/writer threads where terminated on connection re-initializtion of {0}. Available permits {1}", logObjects);
         }
+        readerWriterSemaphore.acquire(2);
         // Start the writer thread. This will open an XMPP stream to the server
         packetWriter.init();
         // Start the reader thread. The startup() method will block until we
@@ -859,7 +911,7 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
         if (!config.isCompressionEnabled()) {
             return;
         }
-        maybeCompressFeaturesReceived.checkIfSuccessOrWait();
+
         Compress.Feature compression = getFeature(Compress.Feature.ELEMENT, Compress.NAMESPACE);
         if (compression == null) {
             // Server does not support compression
@@ -910,18 +962,42 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
      *
      * @param e the exception that causes the connection close event.
      */
-    private synchronized void notifyConnectionError(Exception e) {
+    private void notifyConnectionError(final Exception e) {
-        // Listeners were already notified of the exception, return right here.
+        ASYNC_BUT_ORDERED.performAsyncButOrdered(this, new Runnable() {
-        if ((packetReader == null || packetReader.done) &&
+            @Override
-                (packetWriter == null || packetWriter.done())) return;
+            public void run() {
+                // Listeners were already notified of the exception, return right here.
+                if (packetReader.done || packetWriter.done()) return;
 
-        // Closes the connection temporary. A reconnection is possible
+                // Report the failure outside the synchronized block, so that a thread waiting within a synchronized
-        // Note that a connection listener of XMPPTCPConnection will drop the SM state in
+                // function like connect() throws the wrapped exception.
-        // case the Exception is a StreamErrorException.
+                SmackWrappedException smackWrappedException = new SmackWrappedException(e);
-        instantShutdown();
+                tlsHandled.reportGenericFailure(smackWrappedException);
+                saslFeatureReceived.reportGenericFailure(smackWrappedException);
+                maybeCompressFeaturesReceived.reportGenericFailure(smackWrappedException);
+                lastFeaturesReceived.reportGenericFailure(smackWrappedException);
 
-        // Notify connection listeners of the error.
+                synchronized (XMPPTCPConnection.this) {
-        callConnectionClosedOnErrorListener(e);
+                    // Within this synchronized block, either *both* reader and writer threads must be terminated, or
+                    // none.
+                    assert ((packetReader.done && packetWriter.done())
+                            || (!packetReader.done && !packetWriter.done()));
+
+                    // Closes the connection temporary. A reconnection is possible
+                    // Note that a connection listener of XMPPTCPConnection will drop the SM state in
+                    // case the Exception is a StreamErrorException.
+                    instantShutdown();
+                }
+
+                Async.go(new Runnable() {
+                    @Override
+                    public void run() {
+                        // Notify connection listeners of the error.
+                        callConnectionClosedOnErrorListener(e);
+                    }
+                }, XMPPTCPConnection.this + " callConnectionClosedOnErrorListener()");
+            }
+        });
     }
 
     /**
@@ -934,14 +1010,13 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
     }
 
     @Override
-    protected void afterFeaturesReceived() throws NotConnectedException, InterruptedException {
+    protected void afterFeaturesReceived() throws NotConnectedException, InterruptedException, SecurityRequiredByServerException {
         StartTls startTlsFeature = getFeature(StartTls.ELEMENT, StartTls.NAMESPACE);
         if (startTlsFeature != null) {
             if (startTlsFeature.required() && config.getSecurityMode() == SecurityMode.disabled) {
-                SmackException smackException = new SecurityRequiredByServerException();
+                SecurityRequiredByServerException smackException = new SecurityRequiredByServerException();
                 tlsHandled.reportFailure(smackException);
-                notifyConnectionError(smackException);
+                throw smackException;
-                return;
             }
 
             if (config.getSecurityMode() != ConnectionConfiguration.SecurityMode.disabled) {
@@ -992,6 +1067,8 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
 
     protected class PacketReader {
 
+        private final String threadName = "Smack Reader (" + getConnectionCounter() + ')';
+
         XmlPullParser parser;
 
         private volatile boolean done;
@@ -1006,9 +1083,15 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
             Async.go(new Runnable() {
                 @Override
                 public void run() {
-                    parsePackets();
+                    LOGGER.finer(threadName + " start");
+                    try {
+                        parsePackets();
+                    } finally {
+                        LOGGER.finer(threadName + " exit");
+                        XMPPTCPConnection.this.readerWriterSemaphore.release();
+                    }
                 }
-            }, "Smack Reader (" + getConnectionCounter() + ")");
+            }, threadName);
          }
 
         /**
@@ -1228,7 +1311,11 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
                                 LOGGER.info(XMPPTCPConnection.this
                                                 + " received closing </stream> element."
                                                 + " Server wants to terminate the connection, calling disconnect()");
-                                disconnect();
+                                ASYNC_BUT_ORDERED.performAsyncButOrdered(XMPPTCPConnection.this, new Runnable() {
+                                    @Override
+                                    public void run() {
+                                        disconnect();
+                                    }});
                             }
                         }
                         break;
@@ -1257,6 +1344,8 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
     protected class PacketWriter {
         public static final int QUEUE_SIZE = XMPPTCPConnection.QUEUE_SIZE;
 
+        private final String threadName = "Smack Writer (" + getConnectionCounter() + ')';
+
         private final ArrayBlockingQueueWithShutdown<Element> queue = new ArrayBlockingQueueWithShutdown<>(
                         QUEUE_SIZE, true);
 
@@ -1302,9 +1391,15 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
             Async.go(new Runnable() {
                 @Override
                 public void run() {
-                    writePackets();
+                    LOGGER.finer(threadName + " start");
+                    try {
+                        writePackets();
+                    } finally {
+                        LOGGER.finer(threadName + " exit");
+                        XMPPTCPConnection.this.readerWriterSemaphore.release();
+                    }
                 }
-            }, "Smack Writer (" + getConnectionCounter() + ")");
+            }, threadName);
         }
 
         private boolean done() {
@@ -1355,11 +1450,12 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
             instantShutdown = instant;
             queue.shutdown();
             shutdownTimestamp = System.currentTimeMillis();
-            try {
+            if (shutdownDone.isNotInInitialState()) {
-                shutdownDone.checkIfSuccessOrWait();
+                try {
-            }
+                    shutdownDone.checkIfSuccessOrWait();
-            catch (NoResponseException | InterruptedException e) {
+                } catch (NoResponseException | InterruptedException e) {
-                LOGGER.log(Level.WARNING, "shutdownDone was not marked as successful by the writer thread", e);
+                    LOGGER.log(Level.WARNING, "shutdownDone was not marked as successful by the writer thread", e);
+                }
             }
         }
 
@@ -1514,7 +1610,16 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
         private void drainWriterQueueToUnacknowledgedStanzas() {
             List<Element> elements = new ArrayList<>(queue.size());
             queue.drainTo(elements);
-            for (Element element : elements) {
+            for (int i = 0; i < elements.size(); i++) {
+                Element element = elements.get(i);
+                // If the unacknowledgedStanza queue is full, then bail out with a warning message. See SMACK-844.
+                if (unacknowledgedStanzas.remainingCapacity() == 0) {
+                    StreamManagementException.UnacknowledgedQueueFullException exception = StreamManagementException.UnacknowledgedQueueFullException
+                            .newWith(i, elements, unacknowledgedStanzas);
+                    LOGGER.log(Level.WARNING,
+                            "Some stanzas may be lost as not all could be drained to the unacknowledged stanzas queue", exception);
+                    return;
+                }
                 if (element instanceof Stanza) {
                     unacknowledgedStanzas.add((Stanza) element);
                 }
@@ -1719,6 +1824,32 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
         stanzaAcknowledgedListeners.clear();
     }
 
+    /**
+     * Add a Stanza dropped listener.
+     * <p>
+     * Those listeners will be invoked every time a Stanza has been dropped due to a failed SM resume. They will not get
+     * automatically removed. If at least one StanzaDroppedListener is configured, no attempt will be made to retransmit
+     * the Stanzas.
+     * </p>
+     *
+     * @param listener the listener to add.
+     * @since 4.3.3
+     */
+    public void addStanzaDroppedListener(StanzaListener listener) {
+        stanzaDroppedListeners.add(listener);
+    }
+
+    /**
+     * Remove the given Stanza dropped listener.
+     *
+     * @param listener the listener.
+     * @return true if the listener was removed.
+     * @since 4.3.3
+     */
+    public boolean removeStanzaDroppedListener(StanzaListener listener) {
+        return stanzaDroppedListeners.remove(listener);
+    }
+
     /**
      * Add a new Stanza ID acknowledged listener for the given ID.
      * <p>

smack-tcp/src/test/java/org/jivesoftware/smack/tcp/PacketWriterTest.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2014 Florian Schmaus
+ * Copyright 2014-2019 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -49,11 +49,9 @@ public class PacketWriterTest {
     @Test
     public void shouldBlockAndUnblockTest() throws InterruptedException, BrokenBarrierException, NotConnectedException, XmppStringprepException {
         XMPPTCPConnection connection = new XMPPTCPConnection("user", "pass", "example.org");
-        final PacketWriter pw = connection.new PacketWriter();
+        final PacketWriter pw = connection.packetWriter;
-        connection.packetWriter = pw;
-        connection.packetReader = connection.new PacketReader();
         connection.setWriter(new BlockingStringWriter());
-        pw.init();
+        connection.packetWriter.init();
 
         for (int i = 0; i < XMPPTCPConnection.PacketWriter.QUEUE_SIZE; i++) {
             pw.sendStreamElement(new Message());

version.gradle

@@ -1,9 +1,15 @@
 allprojects {
 	ext {
-		shortVersion = '4.3.1'
+		shortVersion = '4.3.4'
 		isSnapshot = true
-		jxmppVersion = '0.6.3'
+		// When using dynamic versions for those, do *not* use [1.0,
-		miniDnsVersion = '0.3.2'
+		// 2.0), since this will also pull in 2.0-alpha1. Instead use
+		// [1.0, 1.0.99].
+		// See also:
+		// - https://issues.apache.org/jira/browse/MNG-6232
+		// - https://issues.igniterealtime.org/browse/SMACK-858
+		jxmppVersion = '[0.6, 0.6.999]'
+		miniDnsVersion = '[0.3, 0.3.999]'
 		smackMinAndroidSdk = 9
 	}
 }