diff --git a/12to11.c b/12to11.c
index 3b19f2f..6aa6061 100644
--- a/12to11.c
+++ b/12to11.c
@@ -236,6 +236,7 @@ XLMain (int argc, char **argv)
   XLInitDrmLease ();
   XLInitPointerConstraints ();
   XLInitRelativePointer ();
+  XLInitKeyboardShortcutsInhibit ();
 
   /* This has to come after the rest of the initialization.  */
   DetermineServerTime ();
diff --git a/Imakefile b/Imakefile
index 4c79140..22547a0 100644
--- a/Imakefile
+++ b/Imakefile
@@ -24,7 +24,7 @@ SRCS = 12to11.c run.c alloc.c fns.c output.c compositor.c       \
   picture_renderer.c explicit_synchronization.c transform.c     \
   wp_viewporter.c decoration.c text_input.c                     \
   single_pixel_buffer.c drm_lease.c pointer_constraints.c       \
-  time.c relative_pointer.c
+  time.c relative_pointer.c keyboard_shortcuts_inhibit.c
 
 OBJS = 12to11.o run.o alloc.o fns.o output.o compositor.o       \
   surface.o region.o shm.o atoms.o subcompositor.o positioner.o \
@@ -35,7 +35,7 @@ OBJS = 12to11.o run.o alloc.o fns.o output.o compositor.o       \
   picture_renderer.o explicit_synchronization.o transform.o     \
   wp_viewporter.o decoration.o text_input.o                     \
   single_pixel_buffer.o drm_lease.o pointer_constraints.o       \
-  time.o relative_pointer.o
+  time.o relative_pointer.o keyboard_shortcuts_inhibit.o
 
 GENHEADERS = transfer_atoms.h
 
@@ -121,6 +121,7 @@ ScannerTarget(single-pixel-buffer-v1)
 ScannerTarget(drm-lease-v1)
 ScannerTarget(pointer-constraints-unstable-v1)
 ScannerTarget(relative-pointer-unstable-v1)
+ScannerTarget(keyboard-shortcuts-inhibit-unstable-v1)
 
 /* Make OBJS depend on scanner headers, and depend on both them and SRCS.  */
 $(OBJS): $(GENHEADERS)
diff --git a/compositor.h b/compositor.h
index e517752..d1c48e2 100644
--- a/compositor.h
+++ b/compositor.h
@@ -892,11 +892,13 @@ typedef struct _RoleFuncs RoleFuncs;
 typedef struct _CommitCallback CommitCallback;
 typedef struct _UnmapCallback UnmapCallback;
 typedef struct _DestroyCallback DestroyCallback;
+typedef struct _ClientData ClientData;
 
 enum _ClientDataType
   {
     SubsurfaceData,
     PointerConfinementData,
+    ShortcutInhibitData,
     MaxClientData,
   };
 
@@ -937,6 +939,21 @@ struct _CommitCallback
   CommitCallback *next, *last;
 };
 
+struct _ClientData
+{
+  /* The next piece of client data attached to this surface.  */
+  ClientData *next;
+
+  /* The client data itself.  */
+  void *data;
+
+  /* The free function.  */
+  void (*free_function) (void *);
+
+  /* The type of the client data.  */
+  ClientDataType type;
+};
+
 struct _Surface
 {
   /* The view associated with this surface.  */
@@ -968,11 +985,8 @@ struct _Surface
   /* List of subsurfaces.  */
   XLList *subsurfaces;
 
-  /* Array of "client data".  */
-  void *client_data[MaxClientData];
-
-  /* List of functions for freeing "client data".  */
-  void (*free_client_data[MaxClientData]) (void *);
+  /* List of client data.  */
+  ClientData *client_data;
 
   /* List of commit callbacks.  */
   CommitCallback commit_callbacks;
@@ -1087,6 +1101,7 @@ extern DestroyCallback *XLSurfaceRunOnFree (Surface *, void (*) (void *),
 extern void XLSurfaceCancelRunOnFree (DestroyCallback *);
 extern void *XLSurfaceGetClientData (Surface *, ClientDataType,
 				     size_t, void (*) (void *));
+extern void *XLSurfaceFindClientData (Surface *, ClientDataType);
 extern Bool XLSurfaceGetResizeDimensions (Surface *, int *, int *);
 extern void XLSurfacePostResize (Surface *, int, int, int, int);
 extern void XLSurfaceMoveBy (Surface *, int, int);
@@ -1450,6 +1465,8 @@ extern void XLSeatLockPointer (Seat *);
 extern void XLSeatUnlockPointer (Seat *);
 extern RelativePointer *XLSeatGetRelativePointer (Seat *, struct wl_resource *);
 extern void XLSeatDestroyRelativePointer (RelativePointer *);
+extern Bool XLSeatApplyExternalGrab (Seat *, Surface *);
+extern void XLSeatCancelExternalGrab (Seat *);
 
 extern Cursor InitDefaultCursor (void);
 
@@ -1623,6 +1640,12 @@ extern void XLInitRelativePointer (void);
 extern void XLRelativePointerSendRelativeMotion (struct wl_resource *,
 						 uint64_t, double, double);
 
+/* Defined in keyboard_shortcuts_inhibit.c.  */
+
+extern void XLInitKeyboardShortcutsInhibit (void);
+extern void XLCheckShortcutInhibition (Seat *, Surface *);
+extern void XLReleaseShortcutInhibition (Seat *, Surface *);
+
 /* Utility functions that don't belong in a specific file.  */
 
 #define ArrayElements(arr) (sizeof (arr) / sizeof (arr)[0])
diff --git a/pointer_constraints.c b/pointer_constraints.c
index 5970840..b670db1 100644
--- a/pointer_constraints.c
+++ b/pointer_constraints.c
@@ -1776,7 +1776,7 @@ Reconfine (Surface *surface, int *root_x, int *root_y,
   if (!XLWindowFromSurface (surface))
     return;
 
-  record = surface->client_data[PointerConfinementData];
+  record = XLSurfaceFindClientData (surface, PointerConfinementData);
 
   if (!record)
     return;
@@ -1813,7 +1813,7 @@ XLPointerBarrierLeft (Seat *seat, Surface *surface)
   /* The pointer has now left the given surface.  If there is an
      active confinement for that surface and seat, disable it.  */
 
-  record = surface->client_data[PointerConfinementData];
+  record = XLSurfaceFindClientData (surface, PointerConfinementData);
 
   if (!record)
     return;
@@ -1834,7 +1834,7 @@ XLPointerBarrierCheck (Seat *seat, Surface *dispatch, double x, double y,
   pixman_box32_t box;
   int offset_x, offset_y;
 
-  record = dispatch->client_data[PointerConfinementData];
+  record = XLSurfaceFindClientData (dispatch, PointerConfinementData);
 
   if (!record)
     return;
@@ -1959,7 +1959,7 @@ XLPointerConstraintsSurfaceMovedTo (Surface *surface, int root_x,
      query for the position manually.  Simply move the lines for the
      surface's window and each of its subsurfaces.  */
 
-  record = surface->client_data[PointerConfinementData];
+  record = XLSurfaceFindClientData (surface, PointerConfinementData);
 
   if (!record)
     return;
diff --git a/seat.c b/seat.c
index 5e3c1bd..aac45bf 100644
--- a/seat.c
+++ b/seat.c
@@ -82,13 +82,14 @@ XLList *live_seats;
 
 enum
   {
-    IsInert	      = 1,
-    IsWindowMenuShown = (1 << 2),
-    IsDragging	      = (1 << 3),
-    IsDropped	      = (1 << 4),
-    IsTextInputSeat   = (1 << 5),
-    IsPointerLocked   = (1 << 6),
-    IsSurfaceCoordSet = (1 << 7),
+    IsInert		  = 1,
+    IsWindowMenuShown	  = (1 << 2),
+    IsDragging		  = (1 << 3),
+    IsDropped		  = (1 << 4),
+    IsTextInputSeat	  = (1 << 5),
+    IsPointerLocked	  = (1 << 6),
+    IsSurfaceCoordSet	  = (1 << 7),
+    IsExternalGrabApplied = (1 << 8),
   };
 
 enum
@@ -362,6 +363,12 @@ struct _Seat
   /* The last user time.  */
   Timestamp last_user_time;
 
+  /* The last time the focus changed into a surface.  */
+  Timestamp last_focus_time;
+
+  /* When the last external grab was applied.  */
+  Time external_grab_time;
+
   /* wl_global associated with this seat.  */
   struct wl_global *global;
 
@@ -1749,7 +1756,7 @@ HandleBind (struct wl_client *client, void *data,
 {
   struct wl_resource *resource;
   char *name;
-  ptrdiff_t length;
+  size_t length;
   Seat *seat;
 
   seat = data;
@@ -2665,7 +2672,7 @@ static void
 SelectDeviceEvents (void)
 {
   XIEventMask mask;
-  ptrdiff_t length;
+  size_t length;
 
   length = XIMaskLen (XI_LASTEVENT);
   mask.mask = alloca (length);
@@ -2864,6 +2871,10 @@ SetFocusSurface (Seat *seat, Surface *focus)
     {
       SendKeyboardLeave (seat, seat->focus_surface);
 
+      /* Cancel any grab that may be associated with shortcut
+	 inhibition.  */
+      XLReleaseShortcutInhibition (seat, seat->focus_surface);
+
       XLSurfaceCancelRunOnFree (seat->focus_destroy_callback);
       seat->focus_destroy_callback = NULL;
       seat->focus_surface = NULL;
@@ -2881,6 +2892,9 @@ SetFocusSurface (Seat *seat, Surface *focus)
       return;
     }
 
+  /* Apply any shortcut inhibition.  */
+  XLCheckShortcutInhibition (seat, focus);
+
   if (input_funcs)
     /* Tell any input method about the change.  */
     input_funcs->focus_in (seat, focus);
@@ -2907,6 +2921,9 @@ DispatchFocusIn (Surface *surface, XIFocusInEvent *event)
   if (!seat)
     return;
 
+  /* Record the time the focus changed for the external grab.  */
+  seat->last_focus_time = TimestampFromServerTime (event->time);
+
   SetFocusSurface (seat, surface);
 }
 
@@ -4553,7 +4570,7 @@ FakePointerEdge (Seat *seat, Surface *target, uint32_t serial,
   Status state;
   Window window;
   XIEventMask mask;
-  ptrdiff_t length;
+  size_t length;
 
   if (edge == NoneEdge)
     return False;
@@ -4751,7 +4768,7 @@ void
 XLSelectStandardEvents (Window window)
 {
   XIEventMask mask;
-  ptrdiff_t length;
+  size_t length;
 
   length = XIMaskLen (XI_LASTEVENT);
   mask.mask = alloca (length);
@@ -4965,7 +4982,7 @@ XLSeatExplicitlyGrabSurface (Seat *seat, Surface *surface, uint32_t serial)
   WhatEdge edge;
   Time time;
   XIEventMask mask;
-  ptrdiff_t length;
+  size_t length;
   Cursor cursor;
 
   if (seat->flags & IsInert
@@ -5017,6 +5034,8 @@ XLSeatExplicitlyGrabSurface (Seat *seat, Surface *surface, uint32_t serial)
   XISetMask (mask.mask, XI_Motion);
   XISetMask (mask.mask, XI_ButtonPress);
   XISetMask (mask.mask, XI_ButtonRelease);
+  XISetMask (mask.mask, XI_KeyPress);
+  XISetMask (mask.mask, XI_KeyRelease);
 
   cursor = (seat->cursor ? seat->cursor->cursor : None);
 
@@ -5036,9 +5055,14 @@ XLSeatExplicitlyGrabSurface (Seat *seat, Surface *surface, uint32_t serial)
      that keyboard focus cannot be changed, which is not very crucial,
      so it is allowed to fail.  */
 
-  XIGrabDevice (compositor.display, seat->master_keyboard,
-		window, time, None, XIGrabModeAsync,
-		XIGrabModeAsync, True, &mask);
+  state = XIGrabDevice (compositor.display, seat->master_keyboard,
+			window, time, None, XIGrabModeAsync,
+			XIGrabModeAsync, True, &mask);
+
+  /* Cancel any external grab that might be applied if the keyboard
+     grab succeeded.  */
+  if (state == Success)
+    seat->flags &= ~IsExternalGrabApplied;
 
   /* And record the grab surface, so that owner_events can be
      implemented correctly.  */
@@ -5332,7 +5356,7 @@ XLSeatBeginDrag (Seat *seat, DataSource *data_source, Surface *start_surface,
   Window window;
   Time time;
   XIEventMask mask;
-  ptrdiff_t length;
+  size_t length;
   WhatEdge edge;
   Status state;
 
@@ -5737,3 +5761,59 @@ XLSeatDestroyRelativePointer (RelativePointer *relative_pointer)
 
   XLFree (relative_pointer);
 }
+
+Bool
+XLSeatApplyExternalGrab (Seat *seat, Surface *surface)
+{
+  Window window;
+  Status state;
+  XIEventMask mask;
+  size_t length;
+
+  /* Grab the toplevel SURFACE on SEAT.  */
+
+  window = XLWindowFromSurface (surface);
+
+  if (!window)
+    return None;
+
+  length = XIMaskLen (XI_LASTEVENT);
+  mask.mask = alloca (length);
+  mask.mask_len = length;
+  mask.deviceid = XIAllMasterDevices;
+
+  memset (mask.mask, 0, length);
+
+  /* Grab focus and key events.  */
+  XISetMask (mask.mask, XI_FocusIn);
+  XISetMask (mask.mask, XI_FocusOut);
+  XISetMask (mask.mask, XI_KeyPress);
+  XISetMask (mask.mask, XI_KeyRelease);
+
+  state = XIGrabDevice (compositor.display, seat->master_keyboard,
+			window, seat->last_focus_time.milliseconds, None,
+			XIGrabModeAsync, XIGrabModeAsync, True, &mask);
+  if (state == Success)
+    {
+      /* Mark an external grab as having been applied.  */
+      seat->flags |= IsExternalGrabApplied;
+
+      /* Record the time when it was applied.  */
+      seat->external_grab_time = seat->last_focus_time.milliseconds;
+
+      return True;
+    }
+
+  return False;
+}
+
+void
+XLSeatCancelExternalGrab (Seat *seat)
+{
+  if (!(seat->flags & IsExternalGrabApplied))
+    return;
+
+  /* Cancel the external grab.  */
+  XIUngrabDevice (compositor.display, seat->master_keyboard,
+		  seat->external_grab_time);
+}
diff --git a/subsurface.c b/subsurface.c
index 92ce10a..b9182ff 100644
--- a/subsurface.c
+++ b/subsurface.c
@@ -792,7 +792,8 @@ Teardown (Surface *surface, Role *role)
       ViewUnparent (surface->under);
       ViewSetSubcompositor (surface->under, NULL);
 
-      client = subsurface->parent->client_data[SubsurfaceData];
+      client = XLSurfaceFindClientData (subsurface->parent,
+					SubsurfaceData);
 
       if (client)
 	{
@@ -986,7 +987,7 @@ XLSubsurfaceHandleParentCommit (Surface *parent)
 {
   SurfaceActionClientData *client;
 
-  client = parent->client_data[SubsurfaceData];
+  client = XLSurfaceFindClientData (parent, SubsurfaceData);
 
   if (client)
     RunSurfaceActions (&client->actions);
diff --git a/surface.c b/surface.c
index 6ec7ec5..a793be6 100644
--- a/surface.c
+++ b/surface.c
@@ -1305,7 +1305,7 @@ static void
 HandleSurfaceDestroy (struct wl_resource *resource)
 {
   Surface *surface;
-  int i;
+  ClientData *data, *last;
 
   surface = wl_resource_get_user_data (resource);
 
@@ -1322,13 +1322,18 @@ HandleSurfaceDestroy (struct wl_resource *resource)
 	      NotifySubsurfaceDestroyed);
 
   /* Then release all client data.  */
-  for (i = 0; i < MaxClientData; ++i)
-    {
-      if (surface->client_data[i])
-	surface->free_client_data[i] (surface->client_data[i]);
-      XLFree (surface->client_data[i]);
+  data = surface->client_data;
 
-      surface->client_data[i] = NULL;
+  while (data)
+    {
+      /* Free the client data.  */
+      data->free_function (data->data);
+      XLFree (data->data);
+
+      /* And its record.  */
+      last = data;
+      data = data->next;
+      XLFree (last);
     }
 
   /* Release the output region.  */
@@ -1641,13 +1646,38 @@ void *
 XLSurfaceGetClientData (Surface *surface, ClientDataType type,
 			size_t size, void (*free_func) (void *))
 {
-  if (surface->client_data[type])
-    return surface->client_data[type];
+  ClientData *data;
 
-  surface->client_data[type] = XLCalloc (1, size);
-  surface->free_client_data[type] = free_func;
+  /* First, look for existing client data.  */
+  for (data = surface->client_data; data; data = data->next)
+    {
+      if (data->type == type)
+	return data->data;
+    }
 
-  return surface->client_data[type];
+  /* Next, allocate some new client data.  */
+  data = XLMalloc (sizeof *data);
+  data->next = surface->client_data;
+  surface->client_data = data;
+  data->data = XLCalloc (1, size);
+  data->free_function = free_func;
+  data->type = type;
+
+  return data->data;
+}
+
+void *
+XLSurfaceFindClientData (Surface *surface, ClientDataType type)
+{
+  ClientData *data;
+
+  for (data = surface->client_data; data; data = data->next)
+    {
+      if (data->type == type)
+	return data->data;
+    }
+
+  return NULL;
 }
 
 Window
diff --git a/text_input.c b/text_input.c
index ca45df9..0feb053 100644
--- a/text_input.c
+++ b/text_input.c
@@ -3217,26 +3217,29 @@ FilterInputCallback (Seat *seat, Surface *surface, void *event,
 
   /* Find the enabled text input.  */
   if (info)
-    input = FindEnabledTextInput (info);
-
-  /* If there is an enabled text input, start filtering the event.  */
-  if (info && input && input->xic)
     {
-      DebugPrint ("found enabled text input %p on client-seat info %p",
-		  input, info);
+      input = FindEnabledTextInput (info);
 
-      /* Convert the extension event into a fake core event that the
-	 input method can understand.  */
-      ConvertKeyEvent (xev, &xkey);
+      /* If there is an enabled text input, start filtering the
+	 event.  */
+      if (input && input->xic)
+	{
+	  DebugPrint ("found enabled text input %p on client-seat info %p",
+		      input, info);
 
-      /* And return the result of filtering the event.  */
-      if (XFilterEvent (&xkey, XLWindowFromSurface (surface)))
-	return True;
+	  /* Convert the extension event into a fake core event that
+	     the input method can understand.  */
+	  ConvertKeyEvent (xev, &xkey);
 
-      /* Otherwise, call XmbLookupString.  If a keysym is returned,
-	 return False.  Otherwise, commit the string looked up and
-	 return True.  */
-      return LookupString (input, &xkey, keysym);
+	  /* And return the result of filtering the event.  */
+	  if (XFilterEvent (&xkey, XLWindowFromSurface (surface)))
+	    return True;
+
+	  /* Otherwise, call XmbLookupString.  If a keysym is
+	     returned, return False.  Otherwise, commit the string
+	     looked up and return True.  */
+	  return LookupString (input, &xkey, keysym);
+	}
     }
 
   /* Otherwise, do nothing.  */