Check for Categories=, closes #909

Author: probonopd

src/appimagetool.c

@@ -658,6 +658,8 @@ main (int argc, char *argv[])
         GKeyFile *kf = g_key_file_new ();
         if (!g_key_file_load_from_file (kf, desktop_file, G_KEY_FILE_KEEP_TRANSLATIONS | G_KEY_FILE_KEEP_COMMENTS, NULL))
             die(".desktop file cannot be parsed");
+        if (!get_desktop_entry(kf, "Categories"))
+            die(".desktop file is missing a Categories= key");
 
         if(verbose){
             fprintf (stderr,"Name: %s\n", get_desktop_entry(kf, "Name"));