INPUT element: Do not update selectionStart/selectionEnd on |value| IDL setter if the new value is …

third_party/WebKit/Source/core/html/forms/TextFieldInputType.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 139 matching lines @@
                                   bool value_changed,
                                   TextFieldEventBehavior event_behavior,
                                   TextControlSetValueSelection selection) {
   // We don't use InputType::setValue.  TextFieldInputType dispatches events
   // different way from InputType::setValue.
   if (event_behavior == kDispatchNoEvent)
     GetElement().SetNonAttributeValue(sanitized_value);
   else
     GetElement().SetNonAttributeValueByUserEdit(sanitized_value);
 
-  if (value_changed)
-    GetElement().UpdateView();
+  // The following early-return can't be moved to the beginning of this
+  // function. We need to update non-attribute value even if the value is not
+  // changed.  For example, <input type=number> has a badInput string, that is
+  // to say, IDL value=="", and new value is "", which should clear the badInput
+  // string and update validiity.
+  if (!value_changed)
+    return;
+  GetElement().UpdateView();
 
   if (selection == TextControlSetValueSelection::kSetSelectionToEnd) {
     unsigned max = VisibleValue().length();
     GetElement().SetSelectionRange(max, max);
   }
 
-  if (!value_changed)
-    return;
-
   switch (event_behavior) {
     case kDispatchChangeEvent:
       // If the user is still editing this field, dispatch an input event rather
       // than a change event.  The change event will be dispatched when editing
       // finishes.
       if (GetElement().IsFocused())
         GetElement().DispatchInputEvent();
       else
         GetElement().DispatchFormControlChangeEvent();
       break;
@@ skipping 377 matching lines @@
   return ShouldSpinButtonRespondToMouseEvents() && GetElement().IsFocused();
 }
 
 void TextFieldInputType::SpinButtonDidReleaseMouseCapture(
     SpinButtonElement::EventDispatch event_dispatch) {
   if (event_dispatch == SpinButtonElement::kEventDispatchAllowed)
     GetElement().DispatchFormControlChangeEvent();
 }
 
 }  // namespace blink