[Mesa-dev] [PATCH v2] wayland/egl: Ensure EGL surface is resized on DRI update_buffers()

[Carlos Garnacho]

Fullscreening and unfullscreening a totem window while playing a video
sometimes results in the video subsurface not changing size along. This
is also reproducible with epiphany.

If a surface gets resized while we have an active back buffer for it, the
resized dimensions won't get neither immediately applied on the resize
callback, nor correctly synchronized on update_buffers(), as the
(now stale) surface size and currently attached buffer size still do match.

There's actually 2 things to synchronize here, first the surface query
size might not be updated yet to the wl_egl_window's (i.e. resize_callback
happened while there is a back buffer), and second the wayland buffers
would need dropping if new surface size differs with the currently attached
buffer. These are done in separate steps now.

v2: Added the 'Fixes' tag

https://bugzilla.redhat.com/show_bug.cgi?id=1650929

Fixes: a9fb331ea7d ("wayland/egl: update surface size on window resize")
Signed-off-by: Carlos Garnacho <carlosg at gnome.org>
Tested-by: Bastien Nocera <hadess at hadess.net>
---
 src/egl/drivers/dri2/platform_wayland.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/egl/drivers/dri2/platform_wayland.c b/src/egl/drivers/dri2/platform_wayland.c
index 8122c811288..d9e484eaed1 100644
--- a/src/egl/drivers/dri2/platform_wayland.c
+++ b/src/egl/drivers/dri2/platform_wayland.c
@@ -597,10 +597,8 @@ update_buffers(struct dri2_egl_surface *dri2_surf)
    struct dri2_egl_display *dri2_dpy =
       dri2_egl_display(dri2_surf->base.Resource.Display);
 
-   if (dri2_surf->base.Width != dri2_surf->wl_win->attached_width ||
-       dri2_surf->base.Height != dri2_surf->wl_win->attached_height) {
-
-      dri2_wl_release_buffers(dri2_surf);
+   if (dri2_surf->base.Width != dri2_surf->wl_win->width ||
+       dri2_surf->base.Height != dri2_surf->wl_win->height) {
 
       dri2_surf->base.Width  = dri2_surf->wl_win->width;
       dri2_surf->base.Height = dri2_surf->wl_win->height;
@@ -608,6 +606,11 @@ update_buffers(struct dri2_egl_surface *dri2_surf)
       dri2_surf->dy = dri2_surf->wl_win->dy;
    }
 
+   if (dri2_surf->base.Width != dri2_surf->wl_win->attached_width ||
+       dri2_surf->base.Height != dri2_surf->wl_win->attached_height) {
+      dri2_wl_release_buffers(dri2_surf);
+   }
+
    if (get_back_bo(dri2_surf) < 0) {
       _eglError(EGL_BAD_ALLOC, "failed to allocate color buffer");
       return -1;
-- 
2.19.2