Fix tab loading icon (flickers with libpng 1.6).

PKGBUILD

@@ -17,13 +17,15 @@ url="http://www.mozilla.org/projects/firefox"
 install=firefox.install
 options=('!emptydirs')
 source=(https://ftp.mozilla.org/pub/mozilla.org/firefox/releases/$pkgver/source/firefox-$pkgver.source.tar.bz2
-        mozconfig firefox.desktop firefox-install-dir.patch vendor.js shared-libs.patch)
+        mozconfig firefox.desktop firefox-install-dir.patch vendor.js shared-libs.patch
+        firefox-20.0.1-fixed-loading-icon.png)
 md5sums=('b822ff4b2348410587dec563235d9320'
          'efdd58626b2f56dea31e26879eb2db3b'
          '6174396b4788deffa399db3f6f010a94'
          '150ac0fb3ac7b2114c8e8851a9e0516c'
          '0d053487907de4376d67d8f499c5502b'
-         '52e52f840a49eb1d14be1c0065b03a93')
+         '52e52f840a49eb1d14be1c0065b03a93'
+         '6e335a517c68488941340ee1c23f97b0')
 
 prepare() {
   cd mozilla-release
@@ -44,6 +46,11 @@ prepare() {
   # configure script misdetects the preprocessor without an optimization level
   # https://bugs.archlinux.org/task/34644
   sed -i '/ac_cpp=/s/$CPPFLAGS/& -O2/' configure
+
+  # Fix tab loading icon (flickers with libpng 1.6)
+  # https://bugzilla.mozilla.org/show_bug.cgi?id=841734
+  cp "$srcdir/firefox-20.0.1-fixed-loading-icon.png" \
+    browser/themes/gnomestripe/tabbrowser/loading.png
 }
 
 build() {