From 4424d2bfd9498b0443f06760105d33fb25b2aa64 Mon Sep 17 00:00:00 2001
From: Marco Bonardo <mbonardo@mozilla.com>
Date: Tue, 13 Mar 2012 12:05:23 +0100
Subject: [PATCH] Bug 734653 - Scrollbox should filter out hidden elements,
 since they are unscrollable. r=mano

---
 toolkit/content/tests/chrome/test_mousescroll.xul | 4 ++++
 toolkit/content/widgets/scrollbox.xml             | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/toolkit/content/tests/chrome/test_mousescroll.xul b/toolkit/content/tests/chrome/test_mousescroll.xul
index 1fe83f5af764..ef315aeb26ec 100644
--- a/toolkit/content/tests/chrome/test_mousescroll.xul
+++ b/toolkit/content/tests/chrome/test_mousescroll.xul
@@ -19,6 +19,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=378028
        rows, so we just choose an arbitrary height limit that should give
        us plenty of vertical scrollability -->
   <richlistbox id="richlistbox" style="height:50px;">
+    <richlistitem id="richlistbox_item0" hidden="true"><label value="Item 0"/></richlistitem>
     <richlistitem id="richlistbox_item1"><label value="Item 1"/></richlistitem>
     <richlistitem id="richlistbox_item2"><label value="Item 2"/></richlistitem>
     <richlistitem id="richlistbox_item3"><label value="Item 3"/></richlistitem>
@@ -30,6 +31,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=378028
   </richlistbox>
 
   <listbox id="listbox" rows="2">
+    <listitem id="listbox_item0" label="Item 0" hidden="true"/>
     <listitem id="listbox_item1" label="Item 1"/>
     <listitem id="listbox_item2" label="Item 2"/>
     <listitem id="listbox_item3" label="Item 3"/>
@@ -43,6 +45,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=378028
   <box orient="horizontal">
     <arrowscrollbox id="hscrollbox" clicktoscroll="true" orient="horizontal"
      smoothscroll="false" style="max-width:80px;" flex="1">
+      <hbox style="width:40px; height:20px; background:black;" hidden="true"/>
       <hbox style="width:40px; height:20px; background:white;"/>
       <hbox style="width:40px; height:20px; background:black;"/>
       <hbox style="width:40px; height:20px; background:white;"/>
@@ -56,6 +59,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=378028
 
   <arrowscrollbox id="vscrollbox" clicktoscroll="true" orient="vertical"
    smoothscroll="false" style="max-height:80px;" flex="1">
+      <vbox style="width:100px; height:40px; background:black;" hidden="true"/>
       <vbox style="width:100px; height:40px; background:white;"/>
       <vbox style="width:100px; height:40px; background:black;"/>
       <vbox style="width:100px; height:40px; background:white;"/>
diff --git a/toolkit/content/widgets/scrollbox.xml b/toolkit/content/widgets/scrollbox.xml
index 67d6eb7add5f..7d30798a1da7 100644
--- a/toolkit/content/widgets/scrollbox.xml
+++ b/toolkit/content/widgets/scrollbox.xml
@@ -190,7 +190,7 @@
       <method name="_canScrollToElement">
         <parameter name="element"/>
         <body>
-          return true;
+          return !element.hidden;
         </body>
       </method>
 
