Stop clamping tabIndex to short range

third_party/WebKit/Source/core/dom/Element.cpp

Index: third_party/WebKit/Source/core/dom/Element.cpp
diff --git a/third_party/WebKit/Source/core/dom/Element.cpp b/third_party/WebKit/Source/core/dom/Element.cpp
index 047e339cba3e817a5c7eb056291cb3d2776f7584..03e35061c9ca40cd5608fab8a1e7dd6096a3019e 100644
--- a/third_party/WebKit/Source/core/dom/Element.cpp
+++ b/third_party/WebKit/Source/core/dom/Element.cpp
@@ -217,7 +217,7 @@ void Element::clearTabIndexExplicitlyIfNeeded() {
     elementRareData()->clearTabIndexExplicitly();
 }
 
-void Element::setTabIndexExplicitly(short tabIndex) {
+void Element::setTabIndexExplicitly(int tabIndex) {
   ensureElementRareData().setTabIndexExplicitly(tabIndex);
 }
 
@@ -225,7 +225,7 @@ void Element::setTabIndex(int value) {
   setIntegralAttribute(tabindexAttr, value);
 }
 
-short Element::tabIndex() const {
+int Element::tabIndex() const {
   return hasRareData() ? elementRareData()->tabIndex() : 0;
 }
 
@@ -2433,11 +2433,7 @@ void Element::parseAttribute(const QualifiedName& name,
         document().setNeedsFocusedElementCheck();
       }
     } else if (parseHTMLInteger(value, tabindex)) {
-      // Clamp tabindex to the range of 'short' to match Firefox's behavior.
-      setTabIndexExplicitly(
-          max(static_cast<int>(std::numeric_limits<short>::min()),
-              std::min(tabindex,
-                       static_cast<int>(std::numeric_limits<short>::max()))));
+      setTabIndexExplicitly(tabindex);

[kochi, 2016/10/18 02:37:24]

Could you add a comment here for the behavior when the parsed value is
out of int ragne?

As far as I read parseHTMLInteger(), if the value is out of int range,
it returns false and thus tabindex will be 0 (set on line 2427).

But in that case, setTabIndexExplicitly(tabindex) will not be called?

If so, it can make some difference in the following case:

1. <div tabindex="3"></div>
    => div.tabIndex = 3
2. div.setAttribute("tabindex", "12039810238102983");
3. the div becomes <div tabindex="12039810238102983"><div> but
   div.tabIndex = 3 or 0?

If you have a test case to catch this, it is nice.

[rwlbuis, 2016/10/19 00:43:43]

Done.
That is correct.
I added a test for this. Turns out it ends up being 3 since the setAttribute
tries to set to an out of range value.

     }
   } else if (name == XMLNames::langAttr) {
     pseudoStateChanged(CSSSelector::PseudoLang);