Bug 676387 - XUL elements with -moz-appearance should ignore clicks in their overflow. r=roc

layout/base/nsDisplayList.cpp

@@ -1023,12 +1023,15 @@ nsDisplayBackground::HitTest(nsDisplayListBuilder* aBuilder,
                              HitTestState* aState,
                              nsTArray<nsIFrame*> *aOutFrames)
 {
-  // For theme backgrounds, assume that any point in our bounds is a hit.
-  // We don't know the true hit region of the theme background.
-  if (!mIsThemed &&
-      !RoundedBorderIntersectsRect(mFrame, ToReferenceFrame(), aRect)) {
-    // aRect doesn't intersect our border-radius curve.
-    return;
+  if (mIsThemed) {
+    // For theme backgrounds, assume that any point in our border rect is a hit.
+    if (!nsRect(ToReferenceFrame(), mFrame->GetSize()).Intersects(aRect))
+      return;
+  } else {
+    if (!RoundedBorderIntersectsRect(mFrame, ToReferenceFrame(), aRect)) {
+      // aRect doesn't intersect our border-radius curve.
+      return;
+    }
   }
 
   aOutFrames->AppendElement(mFrame);

layout/reftests/native-theme/676387-1-ref.xul

@@ -0,0 +1,6 @@
+<?xml version="1.0"?>
+<?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
+<window id="window676387-1-ref"
+        xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+  <hbox><button id="button" label="SUCCESS"/></hbox>
+</window>

layout/reftests/native-theme/676387-1.xul

@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+<?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
+<window id="window676387-1"
+        class="reftest-wait"
+        xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
+        onload="var button = document.getElementById('button');
+                var r = button.getBoundingClientRect();
+                if (document.elementFromPoint(r.right, r.top) == button.parentNode)
+                  button.label = 'SUCCESS';
+                document.documentElement.className = '';">
+  <hbox><button id="button" label="FAIL"/></hbox>
+</window>

layout/reftests/native-theme/reftest.list

@@ -78,3 +78,5 @@ skip-if(!winWidget) == scroll-thumb-minimum-size-notheme.html scroll-thumb-minim
 # animated progress bars.
 skip-if(cocoaWidget) skip-if(winWidget) == progress-overflow.html progress-overflow-ref.html
 skip-if(cocoaWidget) skip-if(winWidget) != progress-overflow-small.html progress-nobar.html
+
+== 676387-1.xul 676387-1-ref.xul