Bug 1365395 - Resetting select should reset option dirtiness too. r=smaug

Also added a extra flag NO_RESELECT, to avoid selecting the same option (with
default value false) again after setting it to its default value, and later no
way of deselecting it because it's dirtiness is set to false already.

MozReview-Commit-ID: L35sBMWwi3m

dom/html/HTMLOptionElement.h

@@ -44,6 +44,11 @@ public:
   bool Selected() const;
   bool DefaultSelected() const;
 
+  void SetSelectedChanged(bool aValue)
+  {
+    mSelectedChanged = aValue;
+  }
+
   virtual nsChangeHint GetAttributeChangeHint(const nsIAtom* aAttribute,
                                               int32_t aModType) const override;
 

dom/html/HTMLSelectElement.cpp

@@ -1072,7 +1072,7 @@ HTMLSelectElement::SetOptionsSelectedByIndex(int32_t aStartIndex,
   }
 
   // Make sure something is selected unless we were set to -1 (none)
-  if (optionsDeselected && aStartIndex != -1) {
+  if (optionsDeselected && aStartIndex != -1 && !(aOptionsMask & NO_RESELECT)) {
     optionsSelected =
       CheckSelectSomething(aOptionsMask & NOTIFY) || optionsSelected;
   }
@@ -1646,13 +1646,14 @@ HTMLSelectElement::Reset()
       // Reset the option to its default value
       //
 
-      uint32_t mask = SET_DISABLED | NOTIFY;
+      uint32_t mask = SET_DISABLED | NOTIFY | NO_RESELECT;
       if (option->DefaultSelected()) {
         mask |= IS_SELECTED;
         numSelected++;
       }
 
       SetOptionsSelectedByIndex(i, i, mask);
+      option->SetSelectedChanged(false);
     }
   }
 

dom/html/HTMLSelectElement.h

@@ -134,12 +134,16 @@ public:
    *                (for JavaScript)
    *
    *  NOTIFY        whether to notify frames and such
+   *
+   *  NO_RESELECT   no need to select something after an option is deselected
+   *                (for reset)
    */
   enum OptionType {
     IS_SELECTED   = 1 << 0,
     CLEAR_ALL     = 1 << 1,
     SET_DISABLED  = 1 << 2,
-    NOTIFY        = 1 << 3
+    NOTIFY        = 1 << 3,
+    NO_RESELECT   = 1 << 4
   };
 
   using nsIConstraintValidation::GetValidationMessage;