Implement --print-cache-file option to print the path to the
cache file used by gdk-pixbuf.

--- docs/reference/gdk-pixbuf/gdk-pixbuf-query-loaders.1.orig	2010-10-23 15:38:09.302070058 +0200
+++ docs/reference/gdk-pixbuf/gdk-pixbuf-query-loaders.1	2010-10-23 15:39:56.156994937 +0200
@@ -7,7 +7,7 @@
 .\"    Source: [FIXME: source]
 .\"  Language: English
 .\"
-.TH "GDK\-PIXBUF\-QUERY\-" "1" "09/21/2010" "[FIXME: source]" "[FIXME: manual]"
+.TH "GDK\-PIXBUF\-QUERY\-" "1" "10/23/2010" "[FIXME: source]" "[FIXME: manual]"
 .\" -----------------------------------------------------------------
 .\" * Define some portability stuff
 .\" -----------------------------------------------------------------
@@ -59,6 +59,11 @@ gdk\-pixbuf
 at the file\&.
 .SH "OPTIONS"
 .PP
+\-\-print\-cache\-file
+Prints the full path to the default cache file to stdout.
+.RS 4
+.RE
+.PP
 \-\-update\-cache
 .RS 4
 Write the output to the default cache location instead of
--- gdk-pixbuf/queryloaders.c.orig	2010-10-23 15:34:28.360421197 +0200
+++ gdk-pixbuf/queryloaders.c	2010-10-23 15:36:27.509779280 +0200
@@ -283,7 +283,11 @@ int main (int argc, char **argv)
 
 #endif
 
-        if (argc > 1 && strcmp (argv[1], "--update-cache") == 0) {
+	if (argc > 1 && strcmp (argv[1], "--print-cache-file") == 0) {
+		cache_file = gdk_pixbuf_get_module_file ();
+		printf ("%s\n", cache_file);
+		return 0;
+	} else if (argc > 1 && strcmp (argv[1], "--update-cache") == 0) {
                 cache_file = gdk_pixbuf_get_module_file ();
                 first_file = 2;
         }