From cb70a86200bf98f77e80a3c8b856e92739f2e9f3 Mon Sep 17 00:00:00 2001
From: YFdyh000 <yfdyh000@gmail.com>
Date: Sun, 7 Sep 2014 20:04:53 +0800
Subject: [PATCH] Fix the 'scrollbutton' in Tabbar is always not visible in
 Firefox 32+.

I has tested the in Fx31 and Fx32, that is ok.

This bug is due to:
https://bugzilla.mozilla.org/show_bug.cgi?id=878020

References:
https://hg.mozilla.org/releases/mozilla-release/diff/bbfe5c6ea7c9/toolkit/content/widgets/scrollbox.xml
http://hg.mozilla.org/mozilla-central/raw-file/2255d7d187b2/toolkit/content/widgets/scrollbox.xml
---
 chrome/content/tabutils.xml | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/chrome/content/tabutils.xml b/chrome/content/tabutils.xml
index 09b61a4..61b653e 100644
--- a/chrome/content/tabutils.xml
+++ b/chrome/content/tabutils.xml
@@ -44,8 +44,8 @@
           </xul:toolbarbutton>
         </xul:hbox>
       </xul:hbox>
-      <xul:toolbarbutton class="scrollbutton-up" collapsed="true"
-                         xbl:inherits="orient"
+      <xul:toolbarbutton class="scrollbutton-up"
+                         xbl:inherits="orient,collapsed=notoverflowing,disabled=scrolledtostart"
                          anonid="scrollbutton-up"
                          onclick="_distanceScroll(event);"
                          onmousedown="if (event.button == 0) _startScroll(-1);"
@@ -53,14 +53,18 @@
                          onmouseover="_continueScroll(-1);"
                          onmouseout="_pauseScroll();"
                          chromedir="&locale.dir;"/>
+      <xul:spacer class="arrowscrollbox-overflow-start-indicator"
+                  xbl:inherits="collapsed=scrolledtostart"/>
       <xul:scrollbox class="arrowscrollbox-scrollbox"
                      anonid="scrollbox"
                      flex="1"
                      xbl:inherits="orient,align,pack,dir">
         <children/>
       </xul:scrollbox>
-      <xul:toolbarbutton class="scrollbutton-down" collapsed="true"
-                         xbl:inherits="orient"
+      <xul:spacer class="arrowscrollbox-overflow-end-indicator"
+                  xbl:inherits="collapsed=scrolledtoend"/>
+      <xul:toolbarbutton class="scrollbutton-down"
+                         xbl:inherits="orient,collapsed=notoverflowing,disabled=scrolledtoend"
                          anonid="scrollbutton-down"
                          onclick="_distanceScroll(event);"
                          onmousedown="if (event.button == 0) _startScroll(1);"
@@ -73,6 +77,9 @@
     <implementation>
       <constructor>
         <![CDATA[
+          this.setAttribute("notoverflowing", "true");
+          this._updateScrollButtonsDisabledState();
+
           PinnedTabsBar = TU_hookFunc(PlacesToolbar,
             ["PlacesToolbar", "PinnedTabsBar", "g"],
             ["PlacesChevron", "PinnedTabsBarChevron", "g"]