[GtkSearchEngineQuartz] Limit the scope of the Spotlight search.

If the query has a non-null location, set the scope to that directory,
otherwise set it to the local computer.

There is unfortunately no way to get Spotlight to search
non-recursively, nor does NSFileManager offer a convenient search of
the contents of a directory's regular files.

gtk/gtksearchenginequartz.c

@@ -192,6 +192,8 @@ gtk_search_engine_quartz_set_query (GtkSearchEngine *engine,
 				    GtkQuery        *query)
 {
   GtkSearchEngineQuartz *quartz;
+  const char* path = NULL;
+  GFile *location = NULL;
 
   QUARTZ_POOL_ALLOC;
 
@@ -204,11 +206,28 @@ gtk_search_engine_quartz_set_query (GtkSearchEngine *engine,
     g_object_unref (quartz->priv->query);
 
   quartz->priv->query = query;
+  location = gtk_query_get_location (query);
+
+  if (location)
+    path = g_file_peek_path (location);
 
   /* We create a query to look for ".*text.*" in the text contents of
    * all indexed files.  (Should we also search for text in file and folder
    * names?).
    */
+
+  if (path)
+    {
+      NSString *ns_path = [[NSString string] initWithUTF8String:path];
+      [quartz->priv->ns_query setSearchScopes:@[ns_path]];
+    }
+  else
+    {
+      [quartz->priv->ns_query setSearchScopes:@[NSMetadataQueryLocalComputerScope]];
+    }
+
+  [quartz->priv->ns_query setSearchItems:@[(NSString*)kMDItemTextContent,
+                                           (NSString*)kMDItemFSName]];
   [quartz->priv->ns_query setPredicate:
     [NSPredicate predicateWithFormat:
       [NSString stringWithFormat:@"(kMDItemTextContent LIKE[cd] \"*%s*\")",