Fix fallback after multiple matching globs

If the result from magic sniffing doesn't correspond to
any of the matching globs (even via inheritance), and
there *were* matching globs, then don't return the result
from magic sniffing. This is too unreliable, and contradicts
the fact that if there was just one glob, the glob would win
(not the magic). So in that case, fallback to one of the glob
matches.

This required removing the code in cache_magic_lookup_data
which "cleans up" the mimetypes list (from glob matches)
of any glob that doesn't have matching magic. This behaviour
isn't in the spec [1], and prevents having anything to fall
back to in the end, after noticing that the magic should
be ignored after all.

[1] https://specifications.freedesktop.org/shared-mime-info-spec/shared-mime-info-spec-0.21.html#idm45992893989040

Context: https://gitlab.freedesktop.org/xdg/shared-mime-info/-/issues/138

2 files changed, 10 insertions, 26 deletions

diff --git a/src/test-mime-data.c b/src/test-mime-data.c
index f14e4dc..b4dffbb 100644
--- a/src/test-mime-data.c
+++ b/src/test-mime-data.c
@@ -73,8 +73,8 @@ check_mime_type (const char *mt,
       if (xfail)
 	{
 	  xmatch++;
-	  
-	  if (verbose > 1)
+
+	  if (verbose > 0)
 	  printf ("%s, '%s' test: got %s (unexpected match)\n", 
 		  filename, test, mt);
 	}
diff --git a/src/xdgmimecache.c b/src/xdgmimecache.c
index 8b21cef..9df4760 100644
--- a/src/xdgmimecache.c
+++ b/src/xdgmimecache.c
@@ -266,15 +266,13 @@ static const char *
 cache_magic_lookup_data (XdgMimeCache *cache, 
 			 const void   *data, 
 			 size_t        len, 
-			 int          *prio,
-			 const char   *mime_types[],
-			 int           n_mime_types)
+			 int          *prio)
 {
   xdg_uint32_t list_offset;
   xdg_uint32_t n_entries;
   xdg_uint32_t offset;
 
-  int j, n;
+  int j;
 
   *prio = 0;
 
@@ -290,21 +288,6 @@ cache_magic_lookup_data (XdgMimeCache *cache,
 					   data, len, prio);
       if (match)
 	return match;
-      else
-	{
-	  xdg_uint32_t mimetype_offset;
-	  const char *non_match;
-	  
-	  mimetype_offset = GET_UINT32 (cache->buffer, offset + 16 * j + 4);
-	  non_match = cache->buffer + mimetype_offset;
-
-	  for (n = 0; n < n_mime_types; n++)
-	    {
-	      if (mime_types[n] && 
-		  _xdg_mime_mime_type_equal (mime_types[n], non_match))
-		mime_types[n] = NULL;
-	    }
-	}
     }
 
   return NULL;
@@ -678,8 +661,7 @@ cache_get_mime_type_for_data (const void *data,
       int prio;
       const char *match;
 
-      match = cache_magic_lookup_data (cache, data, len, &prio, 
-				       mime_types, n_mime_types);
+      match = cache_magic_lookup_data (cache, data, len, &prio);
       if (prio > priority)
 	{
 	  priority = prio;
@@ -698,9 +680,11 @@ cache_get_mime_type_for_data (const void *data,
           if (mime_types[n] && _xdg_mime_cache_mime_type_subclass(mime_types[n], mime_type))
               return mime_types[n];
         }
-
-      /* Return magic match */
-      return mime_type;
+      if (n == 0)
+        {
+          /* No globs: return magic match */
+          return mime_type;
+        }
     }
 
   /* Pick first glob result, as fallback */