Bug 581576 hung up or too slow when press Enter key on Gmail editor which has a lot of misspelled words r=ehsan, a2.0=dbaron

editor/libeditor/base/nsEditor.cpp

@@ -281,8 +281,12 @@ nsEditor::Init(nsIDOMDocument *aDoc, nsIPresShell* aPresShell, nsIContent *aRoot
 NS_IMETHODIMP
 nsEditor::PostCreate()
 {
-  // Synchronize some stuff for the flags
-  nsresult rv = SetFlags(mFlags);
+  // Synchronize some stuff for the flags.  SetFlags() will initialize
+  // something by the flag difference.  This is first time of that, so, all
+  // initializations must be run.  For such reason, we need to invert mFlags
+  // value first.
+  mFlags = ~mFlags;
+  nsresult rv = SetFlags(~mFlags);
   NS_ENSURE_SUCCESS(rv, rv);
 
   // Set up listeners
@@ -368,9 +372,7 @@ nsEditor::GetDesiredSpellCheckState()
     return PR_FALSE;                    // Spellchecking forced off globally
   }
 
-  // Check for password/readonly/disabled, which are not spellchecked
-  // regardless of DOM
-  if (IsPasswordEditor() || IsReadonly() || IsDisabled()) {
+  if (!CanEnableSpellCheck()) {
     return PR_FALSE;
   }
 
@@ -443,6 +445,11 @@ nsEditor::GetFlags(PRUint32 *aFlags)
 NS_IMETHODIMP
 nsEditor::SetFlags(PRUint32 aFlags)
 {
+  if (mFlags == aFlags) {
+    return NS_OK;
+  }
+
+  PRBool spellcheckerWasEnabled = CanEnableSpellCheck();
   mFlags = aFlags;
 
   if (!mDocWeak || !mPresShellWeak) {
@@ -452,9 +459,11 @@ nsEditor::SetFlags(PRUint32 aFlags)
     return NS_OK;
   }
 
-  // Changing the flags can change whether spellchecking is on, so re-sync it
-  nsresult rv = SyncRealTimeSpell();
-  NS_ENSURE_SUCCESS(rv, rv);
+  // The flag change may cause the spellchecker state change
+  if (CanEnableSpellCheck() != spellcheckerWasEnabled) {
+    nsresult rv = SyncRealTimeSpell();
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
 
   // Might be changing editable state, so, we need to reset current IME state
   // if we're focused and the flag change causes IME state change.
@@ -462,7 +471,7 @@ nsEditor::SetFlags(PRUint32 aFlags)
     // Use "enable" for the default value because if IME is disabled
     // unexpectedly, it makes serious a11y problem.
     PRUint32 newState = nsIContent::IME_STATUS_ENABLE;
-    rv = GetPreferredIMEState(&newState);
+    nsresult rv = GetPreferredIMEState(&newState);
     if (NS_SUCCEEDED(rv)) {
       // NOTE: When the enabled state isn't going to be modified, this method
       // is going to do nothing.

editor/libeditor/base/nsEditor.h

@@ -360,6 +360,13 @@ protected:
 
   nsKeyEvent* GetNativeKeyEvent(nsIDOMKeyEvent* aDOMKeyEvent);
 
+  PRBool CanEnableSpellCheck()
+  {
+    // Check for password/readonly/disabled, which are not spellchecked
+    // regardless of DOM
+    return !IsPasswordEditor() && !IsReadonly() && !IsDisabled();
+  }
+
 public:
 
   /** All editor operations which alter the doc should be prefaced