Bug 1037346 IMEStateManager should ignore a call of UpdateIMEState() which is caused by a call of nsIContent::GetDesiredIMEState() r=smaug

dom/events/IMEStateManager.cpp

@@ -191,6 +191,7 @@ nsIContent* IMEStateManager::sContent = nullptr;
 nsPresContext* IMEStateManager::sPresContext = nullptr;
 bool IMEStateManager::sInstalledMenuKeyboardListener = false;
 bool IMEStateManager::sIsTestingIME = false;
+bool IMEStateManager::sIsGettingNewIMEState = false;
 
 // sActiveIMEContentObserver points to the currently active IMEContentObserver.
 // sActiveIMEContentObserver is null if there is no focused editor.
@@ -568,10 +569,19 @@ IMEStateManager::UpdateIMEState(const IMEState& aNewIMEState,
   PR_LOG(sISMLog, PR_LOG_ALWAYS,
     ("ISM: IMEStateManager::UpdateIMEState(aNewIMEState={ mEnabled=%s, "
      "mOpen=%s }, aContent=0x%p), "
-     "sPresContext=0x%p, sContent=0x%p, sActiveIMEContentObserver=0x%p",
+     "sPresContext=0x%p, sContent=0x%p, sActiveIMEContentObserver=0x%p, "
+     "sIsGettingNewIMEState=%s",
      GetIMEStateEnabledName(aNewIMEState.mEnabled),
      GetIMEStateSetOpenName(aNewIMEState.mOpen), aContent,
-     sPresContext, sContent, sActiveIMEContentObserver));
+     sPresContext, sContent, sActiveIMEContentObserver,
+     GetBoolName(sIsGettingNewIMEState)));
+
+  if (sIsGettingNewIMEState) {
+    PR_LOG(sISMLog, PR_LOG_DEBUG,
+      ("ISM:   IMEStateManager::UpdateIMEState(), "
+       "does nothing because of called while getting new IME state"));
+    return;
+  }
 
   if (NS_WARN_IF(!sPresContext)) {
     PR_LOG(sISMLog, PR_LOG_ERROR,
@@ -659,6 +669,13 @@ IMEStateManager::GetNewIMEState(nsPresContext* aPresContext,
     return IMEState(IMEState::DISABLED);
   }
 
+  // nsIContent::GetDesiredIMEState() may cause a call of UpdateIMEState()
+  // from nsEditor::PostCreate() because GetDesiredIMEState() needs to retrieve
+  // an editor instance for the element if it's editable element.
+  // For avoiding such nested IME state updates, we should set
+  // sIsGettingNewIMEState here and UpdateIMEState() should check it.
+  GettingNewIMEStateBlocker blocker;
+
   IMEState newIMEState = aContent->GetDesiredIMEState();
   PR_LOG(sISMLog, PR_LOG_DEBUG,
     ("ISM:   IMEStateManager::GetNewIMEState() returns { mEnabled=%s, "

dom/events/IMEStateManager.h

@@ -146,6 +146,23 @@ protected:
   static nsPresContext* sPresContext;
   static bool           sInstalledMenuKeyboardListener;
   static bool           sIsTestingIME;
+  static bool           sIsGettingNewIMEState;
+
+  class MOZ_STACK_CLASS GettingNewIMEStateBlocker MOZ_FINAL
+  {
+  public:
+    GettingNewIMEStateBlocker()
+      : mOldValue(IMEStateManager::sIsGettingNewIMEState)
+    {
+      IMEStateManager::sIsGettingNewIMEState = true;
+    }
+    ~GettingNewIMEStateBlocker()
+    {
+      IMEStateManager::sIsGettingNewIMEState = mOldValue;
+    }
+  private:
+    bool mOldValue;
+  };
 
   static IMEContentObserver* sActiveIMEContentObserver;