the patch matching isn't right, as the url has a trailing slash, where the regex looks for end of lin on "download".

fix is:

Index: Slim/Web/HTTP.pm
===================================================================
--- Slim/Web/HTTP.pm    (revision 10335)
+++ Slim/Web/HTTP.pm    (working copy)
@@ -878,7 +878,7 @@
 
           ($body, $mtime, $inode, $size, $contentType) = Slim::Web::Graphics::processCoverArtRequest($client, $path);
 
-       } elsif ($path =~ /music\/(\d+)\/download$/) {
+       } elsif ($path =~ /music\/(\d+)\/download/) {
 
           my $obj = Slim::Schema->find('Track', $1);