Bug 1162818 part.1 nsEditor shouldn't release/forget mComposition becuase it should be handled by it after reframing r=ehsan

dom/events/TextComposition.cpp

@@ -462,6 +462,21 @@ TextComposition::EditorWillHandleCompositionChangeEvent(
     "attribute value of the latest compositionupdate event");
 }
 
+void
+TextComposition::OnEditorDestroyed()
+{
+  MOZ_ASSERT(!mIsEditorHandlingEvent,
+             "The editor should have stopped listening events");
+  nsCOMPtr<nsIWidget> widget = GetWidget();
+  if (NS_WARN_IF(!widget)) {
+    // XXX If this could happen, how do we notify IME of destroying the editor?
+    return;
+  }
+
+  // Try to cancel the composition.
+  RequestToCommit(widget, true);
+}
+
 void
 TextComposition::EditorDidHandleCompositionChangeEvent()
 {

dom/events/TextComposition.h

@@ -124,6 +124,12 @@ public:
   void StartHandlingComposition(nsIEditor* aEditor);
   void EndHandlingComposition(nsIEditor* aEditor);
 
+  /**
+   * OnEditorDestroyed() is called when the editor is destroyed but there is
+   * active composition.
+   */
+  void OnEditorDestroyed();
+
   /**
    * CompositionChangeEventHandlingMarker class should be created at starting
    * to handle text event in focused editor.  This calls

editor/libeditor/nsEditor.cpp

@@ -152,6 +152,10 @@ nsEditor::~nsEditor()
 {
   NS_ASSERTION(!mDocWeak || mDidPreDestroy, "Why PreDestroy hasn't been called?");
 
+  if (mComposition) {
+    mComposition->OnEditorDestroyed();
+    mComposition = nullptr;
+  }
   mTxnMgr = nullptr;
 
   delete mPhonetic;
@@ -345,7 +349,12 @@ nsEditor::InstallEventListeners()
 
   nsEditorEventListener* listener =
     reinterpret_cast<nsEditorEventListener*>(mEventListener.get());
-  return listener->Connect(this);
+  nsresult rv = listener->Connect(this);
+  if (mComposition) {
+    // Restart to handle composition with new editor contents.
+    mComposition->StartHandlingComposition(this);
+  }
+  return rv;
 }
 
 void
@@ -356,8 +365,9 @@ nsEditor::RemoveEventListeners()
   }
   reinterpret_cast<nsEditorEventListener*>(mEventListener.get())->Disconnect();
   if (mComposition) {
+    // Even if this is called, don't release mComposition because this is
+    // may be reused after reframing.
     mComposition->EndHandlingComposition(this);
-    mComposition = nullptr;
   }
   mEventTarget = nullptr;
 }
@@ -2268,7 +2278,7 @@ nsEditor::InsertTextImpl(const nsAString& aStringToInsert,
 
   NS_ENSURE_TRUE(aInOutNode && *aInOutNode && aInOutOffset && aDoc,
                  NS_ERROR_NULL_POINTER);
-  if (!mComposition && aStringToInsert.IsEmpty()) {
+  if (!ShouldHandleIMEComposition() && aStringToInsert.IsEmpty()) {
     return NS_OK;
   }
 
@@ -2307,7 +2317,7 @@ nsEditor::InsertTextImpl(const nsAString& aStringToInsert,
   }
 
   nsresult res;
-  if (mComposition) {
+  if (ShouldHandleIMEComposition()) {
     if (!node->IsNodeOfType(nsINode::eTEXT)) {
       // create a text node
       nsRefPtr<nsTextNode> newNode = aDoc->CreateTextNode(EmptyString());
@@ -2356,7 +2366,7 @@ nsEditor::InsertTextIntoTextNodeImpl(const nsAString& aStringToInsert,
   // aSuppressIME is used when editor must insert text, yet this text is not
   // part of the current IME operation. Example: adjusting whitespace around an
   // IME insertion.
-  if (mComposition && !aSuppressIME) {
+  if (ShouldHandleIMEComposition() && !aSuppressIME) {
     if (!mIMETextNode) {
       mIMETextNode = &aTextNode;
       mIMETextOffset = aOffset;
@@ -4023,6 +4033,15 @@ nsEditor::IsIMEComposing() const
   return mComposition && mComposition->IsComposing();
 }
 
+bool
+nsEditor::ShouldHandleIMEComposition() const
+{
+  // When the editor is being reframed, the old value may be restored with
+  // InsertText().  In this time, the text should be inserted as not a part
+  // of the composition.
+  return mComposition && mDidPostCreate;
+}
+
 nsresult
 nsEditor::DeleteSelectionAndPrepareToCreateNode()
 {

editor/libeditor/nsEditor.h

@@ -589,6 +589,10 @@ public:
    * Returns true if there is composition string and not fixed.
    */
   bool IsIMEComposing() const;
+  /**
+   * Returns true when inserting text should be a part of current composition.
+   */
+  bool ShouldHandleIMEComposition() const;
 
   /** from html rules code - migration in progress */
   static nsresult GetTagString(nsIDOMNode *aNode, nsAString& outString);

editor/libeditor/nsPlaintextEditor.cpp

@@ -710,7 +710,7 @@ NS_IMETHODIMP nsPlaintextEditor::InsertText(const nsAString &aStringToInsert)
   nsCOMPtr<nsIEditRules> kungFuDeathGrip(mRules);
 
   EditAction opID = EditAction::insertText;
-  if (mComposition) {
+  if (ShouldHandleIMEComposition()) {
     opID = EditAction::insertIMEText;
   }
   nsAutoPlaceHolderBatch batch(this, nullptr);