Bug 1218032 part.4 Notify IMEContentObserver of enough safe timing to notify IME of something r=smaug

dom/base/test/test_bug976673.html

@@ -26,6 +26,11 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=976673
 
 SimpleTest.waitForExplicitFinish();
 
+// In e10s mode, ContentCacheInChild tries to retrieve selected text and
+// caret position when IMEContentObserver notifies IME of focus.  At this time,
+// we hit assertion in nsContentIterator.
+SimpleTest.expectAssertions(0, 6);
+
 window.addEventListener("mousedown", function (aEvent) { aEvent.preventDefault(); }, false);
 
 function testSetFocus(aEventType, aCallback)

dom/events/EventStateManager.cpp

@@ -473,6 +473,14 @@ EventStateManager::OnStopObservingContent(
   mIMEContentObserver = nullptr;
 }
 
+void
+EventStateManager::TryToFlushPendingNotificationsToIME()
+{
+  if (mIMEContentObserver) {
+    mIMEContentObserver->TryToFlushPendingNotifications();
+  }
+}
+
 nsresult
 EventStateManager::PreHandleEvent(nsPresContext* aPresContext,
                                   WidgetEvent* aEvent,

dom/events/EventStateManager.h

@@ -146,6 +146,12 @@ public:
   void OnStartToObserveContent(IMEContentObserver* aIMEContentObserver);
   void OnStopObservingContent(IMEContentObserver* aIMEContentObserver);
 
+  /**
+   * TryToFlushPendingNotificationsToIME() suggests flushing pending
+   * notifications to IME to IMEContentObserver.
+   */
+  void TryToFlushPendingNotificationsToIME();
+
   /**
    * Register accesskey on the given element. When accesskey is activated then
    * the element will be notified via nsIContent::PerformAccesskey() method.

dom/events/IMEContentObserver.cpp

@@ -1395,6 +1395,19 @@ IMEContentObserver::FlushMergeableNotifications()
      "finished", this));
 }
 
+void
+IMEContentObserver::TryToFlushPendingNotifications()
+{
+  if (!mQueuedSender || mSendingNotification != NOTIFY_IME_OF_NOTHING) {
+    return;
+  }
+
+  MOZ_LOG(sIMECOLog, LogLevel::Debug,
+    ("IMECO: 0x%p IMEContentObserver::TryToFlushPendingNotifications(), "
+     "performing queued IMENotificationSender forcibly", this));
+  mQueuedSender->Run();
+}
+
 /******************************************************************************
  * mozilla::IMEContentObserver::AChangeEvent
  ******************************************************************************/
@@ -1461,7 +1474,20 @@ IMEContentObserver::AChangeEvent::IsSafeToNotifyIME(
 NS_IMETHODIMP
 IMEContentObserver::IMENotificationSender::Run()
 {
-  MOZ_ASSERT(mIMEContentObserver->mQueuedSender);
+  if (NS_WARN_IF(mIsRunning)) {
+    MOZ_LOG(sIMECOLog, LogLevel::Error,
+      ("IMECO: 0x%p IMEContentObserver::IMENotificationSender::Run(), FAILED, "
+       "called recursively", this));
+    return NS_OK;
+  }
+
+  AutoRestore<bool> running(mIsRunning);
+  mIsRunning = true;
+
+  // This instance was already performed forcibly.
+  if (mIMEContentObserver->mQueuedSender != this) {
+    return NS_OK;
+  }
 
   // NOTE: Reset each pending flag because sending notification may cause
   //       another change.

dom/events/IMEContentObserver.h

@@ -103,6 +103,12 @@ public:
   nsresult GetSelectionAndRoot(nsISelection** aSelection,
                                nsIContent** aRoot) const;
 
+  /**
+   * TryToFlushPendingNotifications() should be called when pending events
+   * should be flushed.  This tries to run the queued IMENotificationSender.
+   */
+  void TryToFlushPendingNotifications();
+
 private:
   ~IMEContentObserver() {}
 
@@ -223,6 +229,7 @@ private:
   public:
     explicit IMENotificationSender(IMEContentObserver* aIMEContentObserver)
       : AChangeEvent(aIMEContentObserver)
+      , mIsRunning(false)
     {
     }
     NS_IMETHOD Run() override;
@@ -232,6 +239,8 @@ private:
     void SendSelectionChange();
     void SendTextChange();
     void SendPositionChange();
+
+    bool mIsRunning;
   };
 
   // mQueuedSender is, it was put into the event queue but not run yet.

dom/events/IMEStateManager.cpp

@@ -515,6 +515,13 @@ IMEStateManager::OnChangeFocusInternal(nsPresContext* aPresContext,
   // editor.
   if (newState.mEnabled == IMEState::PLUGIN) {
     CreateIMEContentObserver(nullptr);
+    if (sActiveIMEContentObserver) {
+      MOZ_LOG(sISMLog, LogLevel::Debug,
+        ("ISM:   IMEStateManager::OnChangeFocusInternal(), an "
+         "IMEContentObserver instance is created for plugin and trying to "
+         "flush its pending notifications..."));
+      sActiveIMEContentObserver->TryToFlushPendingNotifications();
+    }
   }
 
   return NS_OK;
@@ -684,6 +691,14 @@ IMEStateManager::OnFocusInEditor(nsPresContext* aPresContext,
   }
 
   CreateIMEContentObserver(aEditor);
+
+  // Let's flush the focus notification now.
+  if (sActiveIMEContentObserver) {
+    MOZ_LOG(sISMLog, LogLevel::Debug,
+      ("ISM:   IMEStateManager::OnFocusInEditor(), new IMEContentObserver is "
+       "created, trying to flush pending notifications..."));
+    sActiveIMEContentObserver->TryToFlushPendingNotifications();
+  }
 }
 
 // static
@@ -797,6 +812,9 @@ IMEStateManager::UpdateIMEState(const IMEState& aNewIMEState,
   }
 
   if (createTextStateManager) {
+    // XXX In this case, it might not be enough safe to notify IME of anything.
+    //     So, don't try to flush pending notifications of IMEContentObserver
+    //     here.
     CreateIMEContentObserver(aEditor);
   }
 }

layout/base/nsPresShell.cpp

@@ -6988,7 +6988,7 @@ PresShell::HandleEvent(nsIFrame* aFrame,
         aFrame = targetContent->GetPrimaryFrame();
         if (!aFrame) {
           PushCurrentEventInfo(aFrame, targetContent);
-          nsresult rv = HandleEventInternal(aEvent, aEventStatus);
+          nsresult rv = HandleEventInternal(aEvent, aEventStatus, true);
           PopCurrentEventInfo();
           return rv;
         }
@@ -7645,7 +7645,7 @@ PresShell::HandleEvent(nsIFrame* aFrame,
       mCurrentEventFrame = frame;
     }
     if (GetCurrentEventFrame()) {
-      rv = HandleEventInternal(aEvent, aEventStatus);
+      rv = HandleEventInternal(aEvent, aEventStatus, true);
     }
 
 #ifdef DEBUG
@@ -7658,7 +7658,7 @@ PresShell::HandleEvent(nsIFrame* aFrame,
 
     if (!NS_EVENT_NEEDS_FRAME(aEvent)) {
       mCurrentEventFrame = nullptr;
-      return HandleEventInternal(aEvent, aEventStatus);
+      return HandleEventInternal(aEvent, aEventStatus, true);
     }
     else if (aEvent->HasKeyEventMessage()) {
       // Keypress events in new blank tabs should not be completely thrown away.
@@ -7761,7 +7761,7 @@ PresShell::HandlePositionedEvent(nsIFrame* aTargetFrame,
   }
 
   if (GetCurrentEventFrame()) {
-    rv = HandleEventInternal(aEvent, aEventStatus);
+    rv = HandleEventInternal(aEvent, aEventStatus, true);
   }
 
 #ifdef DEBUG
@@ -7787,13 +7787,15 @@ PresShell::HandleEventWithTarget(WidgetEvent* aEvent, nsIFrame* aFrame,
   NS_ENSURE_STATE(!aContent || aContent->GetCrossShadowCurrentDoc() == mDocument);
 
   PushCurrentEventInfo(aFrame, aContent);
-  nsresult rv = HandleEventInternal(aEvent, aStatus);
+  nsresult rv = HandleEventInternal(aEvent, aStatus, false);
   PopCurrentEventInfo();
   return rv;
 }
 
 nsresult
-PresShell::HandleEventInternal(WidgetEvent* aEvent, nsEventStatus* aStatus)
+PresShell::HandleEventInternal(WidgetEvent* aEvent,
+                               nsEventStatus* aStatus,
+                               bool aIsHandlingNativeEvent)
 {
   RefPtr<EventStateManager> manager = mPresContext->EventStateManager();
   nsresult rv = NS_OK;
@@ -7939,6 +7941,14 @@ PresShell::HandleEventInternal(WidgetEvent* aEvent, nsEventStatus* aStatus)
       }
     }
 
+    if (!mIsDestroying && aIsHandlingNativeEvent) {
+      // Ensure that notifications to IME should be sent before getting next
+      // native event from the event queue.
+      // XXX Should we check the event message or event class instead of
+      //     using aIsHandlingNativeEvent?
+      manager->TryToFlushPendingNotificationsToIME();
+    }
+
     switch (aEvent->mMessage) {
     case eKeyPress:
     case eKeyDown:

layout/base/nsPresShell.h

@@ -580,7 +580,7 @@ protected:
     mCurrentEventContent = aTarget;
     nsresult rv = NS_OK;
     if (GetCurrentEventFrame()) {
-      rv = HandleEventInternal(aEvent, aStatus);
+      rv = HandleEventInternal(aEvent, aStatus, true);
     }
     PopCurrentEventInfo();
     return rv;
@@ -669,8 +669,14 @@ protected:
                                  nsEventStatus* aEventStatus);
   void PushCurrentEventInfo(nsIFrame* aFrame, nsIContent* aContent);
   void PopCurrentEventInfo();
+  /**
+   * @param aIsHandlingNativeEvent      true when the caller (perhaps) handles
+   *                                    an event which is caused by native
+   *                                    event.  Otherwise, false.
+   */
   nsresult HandleEventInternal(mozilla::WidgetEvent* aEvent,
-                               nsEventStatus* aStatus);
+                               nsEventStatus* aStatus,
+                               bool aIsHandlingNativeEvent);
   nsresult HandlePositionedEvent(nsIFrame* aTargetFrame,
                                  mozilla::WidgetGUIEvent* aEvent,
                                  nsEventStatus* aEventStatus);