Patch for bumblebee AUR package that improves how the configuration is backed up

bumblebee-2.4.1-6_improved_configuration_backup.patch

diff -Naur a/bumblebee/bumblebee.install b/bumblebee/bumblebee.install
--- a/bumblebee/bumblebee.install	2011-10-05 18:30:14.000000000 +0200
+++ b/bumblebee/bumblebee.install	2011-11-28 09:43:33.079042852 +0100
@@ -28,7 +28,23 @@
 
 _backup() {
     cp "$1" "$1.pacsave"
-    echo "File $1 backed up as $1.pacsave"
+    #echo "File $1 backed up as $1.pacsave"
+}
+
+_restore() {
+    local sumSave
+    local sumNew
+    if [ -f "$1.pacsave" ]; then
+        sumNew=$(openssl dgst -md5 "$1")
+        sumSave=$(openssl dgst -md5 "$1.pacsave")
+        if [ "x${sumSave##* }" = "x${sumNew##* }" ]; then
+            rm "$1.pacsave"
+        else
+            mv "$1" "$1.pacnew"
+            mv "$1.pacsave" "$1"
+            echo "New $1 saved as $1.pacnew"
+        fi
+    fi
 }
 
 pre_upgrade() {
@@ -40,32 +56,37 @@
     if [ -f /etc/bumblebee/xorg.conf.nouveau ]; then
         _backup /etc/bumblebee/xorg.conf.nouveau
     fi
-    if [ -f /etc/bumblebee/bumblebee.conf ]; then
-        _backup /etc/bumblebee/bumblebee.conf
-    fi
 }
 
 post_upgrade() {
     if [ -f /etc/bumblebee/xorg.conf.nvidia ]; then
         _replace_busid /etc/bumblebee/xorg.conf.nvidia
+        _restore /etc/bumblebee/xorg.conf.nvidia
     fi
     if [ -f /etc/bumblebee/xorg.conf.nouveau ]; then
         _replace_busid /etc/bumblebee/xorg.conf.nouveau
+        _restore /etc/bumblebee/xorg.conf.nouveau
     fi
     groupadd bumblebee && echo "Bumblebee group created"
-    echo "Update complete. The configuration files had been changed to their"
-    echo "default settings. You may need to restore them manually"
+    echo "Update complete."
     #rc.d start bumblebee
 }
 
 pre_remove() {
     rc.d stop bumblebee
+    # Backup old config files if they exist
+    if [ -f /etc/bumblebee/xorg.conf.nvidia ]; then
+        _backup /etc/bumblebee/xorg.conf.nvidia
+    fi
+    if [ -f /etc/bumblebee/xorg.conf.nouveau ]; then
+        _backup /etc/bumblebee/xorg.conf.nouveau
+    fi
 }
 
 post_remove() {
     #groupdel bumblebee && echo "Bumblebee group deleted"
-    echo "Uninstallation complete"
-    echo "You may delete the group 'bumblebee' now"
+    echo "Uninstallation complete."
+    echo "You may delete the group 'bumblebee' now."
 }
 
 post_install() {
diff -Naur a/bumblebee/PKGBUILD b/bumblebee/PKGBUILD
--- a/bumblebee/PKGBUILD	2011-11-23 15:34:16.000000000 +0100
+++ b/bumblebee/PKGBUILD	2011-11-28 09:25:42.689074025 +0100
@@ -6,16 +6,17 @@
 pkgdesc="Stable branch of Bumblebee. Optimus Support for Linux Through VirtualGL."
 arch=('i686' 'x86_64')
 depends=('xorg-utils' 'virtualgl' 'nvidia-utils-bumblebee')
+optdepends=('acpi_call: turn on/off discrete card (unstable)')
 if [ "$CARCH" = "x86_64" ]; then
-     optdepends=('lib32-virtualgl: run 32bit applications with optirun'
+     optdepends+=('lib32-virtualgl: run 32bit applications with optirun'
                 'lib32-nvidia-utils-bumblebee: run 32bit applications with optirun')
 fi
-optdepends[${#optdepends[@]}]='acpi_call: turn on/off discrete card (unstable)'
 url="https://github.com/Bumblebee-Project/Bumblebee"
 license=("GPL3")
 install='bumblebee.install'
 conflicts=('bumblebee-nouveau')
 provides=('bumblebee')
+backup=('etc/bumblebee/bumblebee.conf')
 source=("https://github.com/downloads/Bumblebee-Project/Bumblebee/$pkgname-$pkgver.tar.gz" 'bumblebee.handler.archlinux')
 md5sums=('cda3f529b07461cc5abcea58a50df5cc'
          '1bce7fcc4027dfe94f2fda37e7a4bcc8')
@@ -24,11 +25,11 @@
 
 build() {
     cd "$srcdir/$pkgname-$pkgver"
-    mkdir -p $_temp_dir
-    ./install --dest-dir=$_temp_dir \
+    mkdir -p "$_temp_dir"
+    ./install --dest-dir="$_temp_dir" \
     --driver=nouveau,nvidia \
     --actions=build,install
-    install -D -m755 $srcdir/bumblebee.handler.archlinux $_temp_dir/etc/rc.d/bumblebee
+    install -D -m755 "$srcdir/bumblebee.handler.archlinux" "$_temp_dir/etc/rc.d/bumblebee"
 }
 
 package() {