From 0d73c21945710134c500867ab413082ec3e4404f Mon Sep 17 00:00:00 2001
From: Florian Schmaus <flo@geekplace.eu>
Date: Mon, 23 Aug 2021 17:39:59 +0200
Subject: [PATCH] [pubsub] FormNode(Provider) should not fail if there is no
 DataForm

Error IQ respones may not contain a data form, e.g.

<iq type="error" id="6LXNC-48" from="pubsub.openfire.xmpp.test" to="anno@openfire.xmpp.test/5dsi4g084a">
  <pubsub xmlns="http://jabber.org/protocol/pubsub#owner">
    <configure node="fdp/submitted/spot_report"/>
  </pubsub>
  <error code="403" type="auth">
    <forbidden xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/>
  </error>
</iq>

Also FormNode's toXML() already handled the case where submitForm was
'null'. Only the constructor threw a IAE if submitForm was 'null'.

Fixes SMACK-910.

Closes: https://github.com/igniterealtime/Smack/pull/471
---
 .../java/org/jivesoftware/smackx/pubsub/FormNode.java    | 9 +--------
 .../smackx/pubsub/provider/FormNodeProvider.java         | 7 ++++++-
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/FormNode.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/FormNode.java
index 3a6945f0f..ef8f3373c 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/FormNode.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/FormNode.java
@@ -38,11 +38,7 @@ public class FormNode extends NodeExtension {
      * @param submitForm The form
      */
     public FormNode(FormNodeType formType, DataForm submitForm) {
-        super(formType.getNodeElement());
-
-        if (submitForm == null)
-            throw new IllegalArgumentException("Submit form cannot be null");
-        configForm = submitForm;
+        this(formType, null, submitForm);
     }
 
     /**
@@ -55,9 +51,6 @@ public class FormNode extends NodeExtension {
      */
     public FormNode(FormNodeType formType, String nodeId, DataForm submitForm) {
         super(formType.getNodeElement(), nodeId);
-
-        if (submitForm == null)
-            throw new IllegalArgumentException("Submit form cannot be null");
         configForm = submitForm;
     }
 
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/provider/FormNodeProvider.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/provider/FormNodeProvider.java
index 176d71544..329d5791a 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/provider/FormNodeProvider.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/provider/FormNodeProvider.java
@@ -35,6 +35,11 @@ import org.jivesoftware.smackx.xdata.packet.DataForm;
 public class FormNodeProvider extends EmbeddedExtensionProvider<FormNode> {
     @Override
     protected FormNode createReturnExtension(String currentElement, String currentNamespace, Map<String, String> attributeMap, List<? extends ExtensionElement> content) {
-        return new FormNode(FormNodeType.valueOfFromElementName(currentElement, currentNamespace), attributeMap.get("node"), (DataForm) content.iterator().next());
+        DataForm dataForm = null;
+        if (!content.isEmpty()) {
+            dataForm = (DataForm) content.get(0);
+        }
+
+        return new FormNode(FormNodeType.valueOfFromElementName(currentElement, currentNamespace), attributeMap.get("node"), dataForm);
     }
 }