Improve error handling of calls to XGrabKey #431

src/sugar/sugar-key-grabber.c

@@ -173,7 +173,7 @@ grab_key (SugarKeyGrabber *grabber, Key *key, gboolean grab)
         int indexes[N_BITS];/*indexes of bits we need to flip*/
         int i, bit, bits_set_cnt;
         int uppervalue;
-        guint mask_to_traverse = IGNORED_MODS & ~ key->state;
+        guint mask_to_traverse = IGNORED_MODS & ~key->state & GDK_MODIFIER_MASK;
 
         bit = 0;
         for (i = 0; i < N_BITS; i++) {
@@ -200,11 +200,13 @@ grab_key (SugarKeyGrabber *grabber, Key *key, gboolean grab)
 void
 sugar_key_grabber_grab_keys(SugarKeyGrabber *grabber, const char **keys)
 {
-    char **cur = keys;
-    char *key;
-	Key *keyinfo;
+    const char **cur = keys;
+    const char *key;
+    Key *keyinfo = NULL;
+    int min_keycodes, max_keycodes;
 
-    gdk_error_trap_push();
+    XDisplayKeycodes(GDK_DISPLAY_XDISPLAY(gdk_display_get_default()),
+                     &min_keycodes, &max_keycodes);
 
     while (*cur != NULL) {
         key = *cur;
@@ -213,16 +215,34 @@ sugar_key_grabber_grab_keys(SugarKeyGrabber *grabber, const char **keys)
         keyinfo = g_new0 (Key, 1);
         keyinfo->key = g_strdup(key);
 
-        egg_accelerator_parse_virtual (key, &keyinfo->keysym,
-                                       &keyinfo->keycode, &keyinfo->state);
+        if (!egg_accelerator_parse_virtual (key, &keyinfo->keysym,
+                                            &keyinfo->keycode,
+                                            &keyinfo->state)) {
+            g_warning ("Invalid key specified: %s", key);
+            continue;
+        }
+
+        if (keyinfo->keycode < min_keycodes || keyinfo->keycode > max_keycodes) {
+            g_warning ("Keycode out of bounds: %d for key %s", keyinfo->keycode, key);
+            continue;
+        }
+
+        gdk_error_trap_push();
 
         grab_key(grabber, keyinfo, TRUE);
 
-        grabber->keys = g_list_append(grabber->keys, keyinfo);	
+        gdk_flush();
+        gint error_code = gdk_error_trap_pop ();
+        if(!error_code)
+            grabber->keys = g_list_append(grabber->keys, keyinfo);
+        else if(error_code == BadAccess)
+            g_warning ("Grab failed, another application may already have access to key '%s'", key);
+        else if(error_code == BadValue)
+            g_warning ("Grab failed, invalid key %s specified. keysym: %u keycode: %u state: %u",
+                       key, keyinfo->keysym, keyinfo->keycode, keyinfo->state);
+        else
+            g_warning ("Grab failed for key '%s' for unknown reason '%d'", key, error_code);
     }
-
-    gdk_flush();
-    gdk_error_trap_push();
 }
 
 gboolean