Bug 926019 - focus and blur an input element should not trigger change event if content hasn't changed. r=smaug

--HG--
extra : rebase_source : 9d56196ae2597cc21f7366326ce7203fe16e6cfb

dom/html/HTMLInputElement.cpp

@@ -3800,6 +3800,15 @@ HTMLInputElement::PreHandleEvent(EventChainPreVisitor& aVisitor)
   // We must cache type because mType may change during JS event (bug 2369)
   aVisitor.mItemFlags |= mType;
 
+  if (aVisitor.mEvent->mMessage == eFocus &&
+      aVisitor.mEvent->IsTrusted() &&
+      MayFireChangeOnBlur() &&
+      // StartRangeThumbDrag already set mFocusedValue on 'mousedown' before
+      // we get the 'focus' event.
+      !mIsDraggingRange) {
+    GetValue(mFocusedValue);
+  }
+
   // Fire onchange (if necessary), before we do the blur, bug 357684.
   if (aVisitor.mEvent->mMessage == eBlur) {
     // Experimental mobile types rely on the system UI to prevent users to not
@@ -4235,12 +4244,6 @@ HTMLInputElement::PostHandleEvent(EventChainPostVisitor& aVisitor)
 
   if (aVisitor.mEvent->mMessage == eFocus ||
       aVisitor.mEvent->mMessage == eBlur) {
-    if (aVisitor.mEvent->mMessage == eFocus &&
-        MayFireChangeOnBlur() &&
-        !mIsDraggingRange) { // StartRangeThumbDrag already set mFocusedValue
-      GetValue(mFocusedValue);
-    }
-
     if (aVisitor.mEvent->mMessage == eBlur) {
       if (mIsDraggingRange) {
         FinishRangeThumbDrag();

dom/html/test/forms/test_change_event.html

@@ -32,6 +32,10 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=722599
 <input type="number" id="input_number" onchange="++numberChange;"></input>
 <input type="range" id="input_range" onchange="++rangeChange;"></input>
 
+<!-- Input text with default value and blurs on focus-->
+<input type="text" id="input_text_value" onchange="++textInputValueChange"
+  onfocus="this.blur();" value="foo"></input>
+ 
 </div>
 <pre id="test">
 <script class="testbody" type="text/javascript">
@@ -42,6 +46,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=722599
 
   var textareaChange = 0;
   var fileInputChange = 0;
+  var textInputValueChange = 0;
 
   var textInputTypes = ["text", "email", "search", "tel", "url", "password"];
   var textInputChange = [0, 0, 0, 0, 0, 0];
@@ -236,6 +241,15 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=722599
     input.blur();
     is(NonTextInputChange[5], 1, "Change event shouldn't be dispatched for checkbox ---> text input type change");
 
+    setTimeout(testInputWithDefaultValue, 0);
+  }
+
+  function testInputWithDefaultValue() {
+    // focus and blur an input text should not trigger change event if content hasn't changed.
+    var input = document.getElementById('input_text_value');
+    input.focus();
+    is(textInputValueChange, 0, "change event shouldn't be dispatched on input text with default value");
+
     SimpleTest.finish();
   }