From d90b14c7687635bc6f9ace9ef5fa897405a0fe09 Mon Sep 17 00:00:00 2001
From: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Date: Thu, 22 Feb 2024 10:04:26 -0500
Subject: [PATCH] egl/wayland/sw: fix no-op updating of current backbuffer

if the frontbuffer is the backbuffer then its contents are up-to-date

Acked-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27703>
---
 src/egl/drivers/dri2/platform_wayland.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/egl/drivers/dri2/platform_wayland.c b/src/egl/drivers/dri2/platform_wayland.c
index f1c1b08b0b9..8109b033dc6 100644
--- a/src/egl/drivers/dri2/platform_wayland.c
+++ b/src/egl/drivers/dri2/platform_wayland.c
@@ -2432,12 +2432,14 @@ dri2_wl_swrast_get_image(__DRIdrawable *read, int x, int y, int w, int h,
    char *src, *dst;
 
    src = dri2_wl_swrast_get_frontbuffer_data(dri2_surf);
+   /* this is already the most up-to-date buffer */
+   if (src == data)
+      return;
    if (!src) {
       memset(data, 0, copy_width * h);
       return;
    }
 
-   assert(data != src);
    assert(copy_width <= src_stride);
 
    src += x_offset;