gdkpixbuf: simplify setup hook, don't create per-package loaders.cache

pkgs/development/libraries/gdk-pixbuf/setup-hook.sh

@@ -1,23 +1,15 @@
 findGdkPixbufLoaders() {
 
-	if [ -n "$out" ] && [ -z "$IN_NIX_SHELL" ]; then
-
-		# set pixbuf loaders.cache for this package
-
-		local loadersDir="$out/lib/gdk-pixbuf-loaders-2.0/$name"
-		mkdir -p "$loadersDir"
-		
-		if [ -f "$1/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache" ]; then
-			cat "$1/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache" >> "$loadersDir/loaders.cache"
+	# choose the longest loaders.cache
+	local loadersCache="$1/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache"
+	if [ -f "$loadersCache" ]; then
+		if [ -f "$GDK_PIXBUF_MODULE_FILE" ]; then
+			if [ $(cat "$loadersCache"|wc -l) -gt $(cat "$GDK_PIXBUF_MODULE_FILE"|wc -l) ]; then
+				export GDK_PIXBUF_MODULE_FILE="$loadersCache"
+			fi
+		else
+			export GDK_PIXBUF_MODULE_FILE="$loadersCache"
 		fi
-	
-		if [ -f "$1/lib/gdk-pixbuf/loaders.cache" ]; then
-			cat "$1/lib/gdk-pixbuf/loaders.cache" >> "$loadersDir/loaders.cache"
-		fi
-		
-		# note, this is not a search path
-		export GDK_PIXBUF_MODULE_FILE=$(readlink -e "$loadersDir/loaders.cache")
-
 	fi
 
 }

pkgs/development/libraries/librsvg/default.nix

@@ -34,7 +34,7 @@ stdenv.mkDerivation rec {
   # The loaders.cache can be used by setting GDK_PIXBUF_MODULE_FILE to
   # point to this file in a wrapper.
   postConfigure = ''
-    GDK_PIXBUF=$out/lib/gdk-pixbuf
+    GDK_PIXBUF=$out/lib/gdk-pixbuf-2.0/2.10.0
     mkdir -p $GDK_PIXBUF/loaders
     sed -e "s#gdk_pixbuf_moduledir = .*#gdk_pixbuf_moduledir = $GDK_PIXBUF/loaders#" \
         -i gdk-pixbuf-loader/Makefile
@@ -43,4 +43,11 @@ stdenv.mkDerivation rec {
     sed -e "s#\$(GDK_PIXBUF_QUERYLOADERS)#GDK_PIXBUF_MODULEDIR=$GDK_PIXBUF/loaders \$(GDK_PIXBUF_QUERYLOADERS)#" \
          -i gdk-pixbuf-loader/Makefile
   '';
+
+  # Merge gdkpixbuf and librsvg loaders
+  postInstall = ''
+    mv $GDK_PIXBUF/loaders.cache $GDK_PIXBUF/loaders.cache.tmp
+    cat ${gdk_pixbuf}/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache $GDK_PIXBUF/loaders.cache.tmp > $GDK_PIXBUF/loaders.cache
+    rm $GDK_PIXBUF/loaders.cache.tmp
+  '';
 }