wayland/egl: Ensure correct buffer size when allocating

Whenever a buffer is allocated, e.g. by the first draw call or EGL call after a
buffer swap, make sure the size is up to date. Prior to this commit, we
failed to do so when querying the buffer age, or swapping buffers
without any prior EGL call or draw call.

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
diff --git a/src/egl/drivers/dri2/platform_wayland.c b/src/egl/drivers/dri2/platform_wayland.c
index bf4f253..0f5d85b 100644
--- a/src/egl/drivers/dri2/platform_wayland.c
+++ b/src/egl/drivers/dri2/platform_wayland.c
@@ -675,6 +675,15 @@
    return 0;
 }
 
+static int
+update_buffers_if_needed(struct dri2_egl_surface *dri2_surf)
+{
+   if (dri2_surf->back != NULL)
+      return 0;
+
+   return update_buffers(dri2_surf);
+}
+
 static __DRIbuffer *
 dri2_wl_get_buffers_with_format(__DRIdrawable * driDrawable,
                                 int *width, int *height,
@@ -992,7 +1001,7 @@
 
    /* Make sure we have a back buffer in case we're swapping without ever
     * rendering. */
-   if (get_back_bo(dri2_surf) < 0)
+   if (update_buffers_if_needed(dri2_surf) < 0)
       return _eglError(EGL_BAD_ALLOC, "dri2_swap_buffers");
 
    if (draw->SwapInterval > 0) {
@@ -1078,7 +1087,7 @@
 {
    struct dri2_egl_surface *dri2_surf = dri2_egl_surface(surface);
 
-   if (get_back_bo(dri2_surf) < 0) {
+   if (update_buffers_if_needed(dri2_surf) < 0) {
       _eglError(EGL_BAD_ALLOC, "dri2_query_buffer_age");
       return -1;
    }