From 0612e0df6e104a5b76b8c95c2f40805198d81f2a Mon Sep 17 00:00:00 2001
From: hujianwei <hujianwei@localhost.localdomain>
Date: Sun, 23 Oct 2022 08:47:27 +0000
Subject: [PATCH] Fix display of deferred frames

* subcompositor.c (SubcompositorUpdate): Always call note frame
callback.
* xdg_surface.c (MaybeRunLateFrame): New function.
(AfterFrame, NoteFrame): Potentially run late frames.
---
 subcompositor.c | 13 +++++++------
 xdg_surface.c   | 40 ++++++++++++++++++++++++++++++++++++----
 2 files changed, 43 insertions(+), 10 deletions(-)

diff --git a/subcompositor.c b/subcompositor.c
index 21d9c7d..7737b16 100644
--- a/subcompositor.c
+++ b/subcompositor.c
@@ -2448,6 +2448,13 @@ SubcompositorUpdate (Subcompositor *subcompositor)
       StorePreviousDamage (subcompositor, NULL);
     }
 
+  /* Increase the frame count and announce the new frame number.  This
+     must be done even if no graphics changes were committed.  */
+  if (subcompositor->note_frame)
+    subcompositor->note_frame (ModeStarted,
+			       ++subcompositor->frame_counter,
+			       subcompositor->note_frame_data);
+
   /* If there's nothing to do, return.  */
 
   if (!start)
@@ -2455,12 +2462,6 @@ SubcompositorUpdate (Subcompositor *subcompositor)
        this case, because the surface should now be unmapped.  */
     goto complete;
 
-  /* Increase the frame count and announce the new frame number.  */
-  if (subcompositor->note_frame)
-    subcompositor->note_frame (ModeStarted,
-			       ++subcompositor->frame_counter,
-			       subcompositor->note_frame_data);
-
   /* Now update all views from start onwards.  */
 
   list = start->link;
diff --git a/xdg_surface.c b/xdg_surface.c
index 18ec0f3..6084501 100644
--- a/xdg_surface.c
+++ b/xdg_surface.c
@@ -940,6 +940,30 @@ HandleResourceDestroy (struct wl_resource *resource)
   ReleaseBacking (role);
 }
 
+static Bool
+MaybeRunLateFrame (XdgRole *role)
+{
+  /* If there is a late frame, run it now.  Return whether or not a
+     late frame was run.  */
+
+  if (role->state & StateLateFrame)
+    {
+      /* Clear the late frame flag.  */
+      role->state &= ~StateLateFrame;
+
+      if (role->state & StateLateFrameAcked)
+	XLFrameClockUnfreeze (role->clock);
+
+      /* Now apply the state in the late frame.  */
+      SubcompositorUpdate (role->subcompositor);
+
+      /* Return True, as a new update has started.  */
+      return True;
+    }
+
+  return False;
+}
+
 static void
 AfterFrame (FrameClock *clock, void *data)
 {
@@ -947,6 +971,10 @@ AfterFrame (FrameClock *clock, void *data)
 
   role = data;
 
+  /* Run any late frame.  */
+  if (MaybeRunLateFrame (role))
+    return;
+
   /* If all pending frames have been drawn, run frame callbacks.
      Unless some buffers have not yet been released, in which case the
      callbacks will be run when they are.  */
@@ -1267,15 +1295,20 @@ NoteFrame (FrameMode mode, uint64_t id, void *data)
 	  /* End the frame.  */
 	  XLFrameClockEndFrame (role->clock);
 
+	  /* Clear the frame completed flag.  */
+	  role->state &= ~StateFrameStarted;
+
 	  /* No frame was started clock-side for this frame.  That
 	     means programs waiting for frame callbacks will not get
 	     any, so the frame callbacks must be run by hand.  */
 	  if (!(role->state & StateFrameStarted)
 	      || !IsRoleMapped (role))
-	    RunFrameCallbacksConditionally (role);
+	    {
+	      if (MaybeRunLateFrame (role))
+		return;
 
-	  /* Clear the frame completed flag.  */
-	  role->state &= ~StateFrameStarted;
+	      RunFrameCallbacksConditionally (role);
+	    }
 
 	  if (mode == ModePresented
 	      && renderer_flags & SupportsDirectPresent)
@@ -1574,7 +1607,6 @@ XLGetXdgSurface (struct wl_client *client, struct wl_resource *resource,
 
   role->subcompositor = MakeSubcompositor ();
   role->clock = XLMakeFrameClockForWindow (role->window);
-
   XLFrameClockSetFreezeCallback (role->clock, HandleFreeze, role);
 
   SubcompositorSetTarget (role->subcompositor, &role->target);