[gnome-flashback] shell: don't grab keybinding if devirtualization failed

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 803e63fb8d59ba70e5e268c25ba41212b783f70e
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Wed Jun 3 21:23:18 2015 +0300

    shell: don't grab keybinding if devirtualization failed

 gnome-flashback/libshell/flashback-key-bindings.c |   66 ++++++++++++---------
 1 files changed, 39 insertions(+), 27 deletions(-)
---
diff --git a/gnome-flashback/libshell/flashback-key-bindings.c 
b/gnome-flashback/libshell/flashback-key-bindings.c
index 30db02b..337512f 100644
--- a/gnome-flashback/libshell/flashback-key-bindings.c
+++ b/gnome-flashback/libshell/flashback-key-bindings.c
@@ -55,33 +55,44 @@ static guint ScrollLockMask = 0;
 
 G_DEFINE_TYPE_WITH_PRIVATE (FlashbackKeyBindings, flashback_key_bindings, G_TYPE_OBJECT)
 
-static guint
-get_real_modifiers (GdkModifierType modifiers)
+static gboolean
+devirtualize_modifiers (GdkModifierType  modifiers,
+                        GdkModifierType  gdk_mask,
+                        unsigned int     real_mask,
+                        unsigned int    *mask)
 {
-       guint mods = 0;
-
-       if (modifiers & GDK_SHIFT_MASK)
-               mods |= ShiftMask;
-       if (modifiers & GDK_CONTROL_MASK)
-               mods |= ControlMask;
-       if (modifiers & GDK_MOD1_MASK)
-               mods |= Mod1Mask;
-       if (modifiers & GDK_META_MASK)
-               mods |= MetaMask;
-       if (modifiers & GDK_HYPER_MASK)
-               mods |= HyperMask;
-       if (modifiers & GDK_SUPER_MASK)
-               mods |= SuperMask;
-       if (modifiers & GDK_MOD2_MASK)
-               mods |= Mod2Mask;
-       if (modifiers & GDK_MOD3_MASK)
-               mods |= Mod3Mask;
-       if (modifiers & GDK_MOD4_MASK)
-               mods |= Mod4Mask;
-       if (modifiers & GDK_MOD5_MASK)
-               mods |= Mod5Mask;
-
-       return mods;
+  if (modifiers & gdk_mask)
+    {
+      if (real_mask == 0)
+        return FALSE;
+
+       *mask |= real_mask;
+    }
+
+  return TRUE;
+}
+
+static gboolean
+get_real_modifiers (GdkModifierType  modifiers,
+                    guint           *mask)
+{
+       gboolean devirtualized;
+
+       devirtualized = TRUE;
+       *mask = 0;
+
+       devirtualized &= devirtualize_modifiers (modifiers, GDK_SHIFT_MASK, ShiftMask, mask);
+       devirtualized &= devirtualize_modifiers (modifiers, GDK_CONTROL_MASK, ControlMask, mask);
+       devirtualized &= devirtualize_modifiers (modifiers, GDK_MOD1_MASK, Mod1Mask, mask);
+       devirtualized &= devirtualize_modifiers (modifiers, GDK_META_MASK, MetaMask, mask);
+       devirtualized &= devirtualize_modifiers (modifiers, GDK_HYPER_MASK, HyperMask, mask);
+       devirtualized &= devirtualize_modifiers (modifiers, GDK_SUPER_MASK, SuperMask, mask);
+       devirtualized &= devirtualize_modifiers (modifiers, GDK_MOD2_MASK, Mod2Mask, mask);
+       devirtualized &= devirtualize_modifiers (modifiers, GDK_MOD3_MASK, Mod3Mask, mask);
+       devirtualized &= devirtualize_modifiers (modifiers, GDK_MOD4_MASK, Mod4Mask, mask);
+       devirtualized &= devirtualize_modifiers (modifiers, GDK_MOD5_MASK, Mod5Mask, mask);
+
+       return devirtualized;
 }
 
 static GVariant *
@@ -278,7 +289,8 @@ flashback_key_bindings_grab (FlashbackKeyBindings *bindings,
        if (keycode == 0)
                return 0;
 
-       real_modifiers = get_real_modifiers (modifiers);
+       if (!get_real_modifiers (modifiers, &real_modifiers))
+               return 0;
 
        flashback_key_bindings_change_keygrab (bindings,
                                               TRUE,