From 945a346596b163e459d7bd4896258f8546c861b2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Mon, 10 May 2021 17:49:15 +0200
Subject: [PATCH] =?UTF-8?q?shm:=20clear=20buffer=E2=80=99s=20dirty=20regio?=
 =?UTF-8?q?n=20before=20returning=20a=20cached=20buffer?=
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A non-busy buffer should always have an empty dirty region
---
 render.c | 2 --
 shm.c    | 1 +
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/render.c b/render.c
index c65cc7e9..a7297412 100644
--- a/render.c
+++ b/render.c
@@ -2290,8 +2290,6 @@ grid_render(struct terminal *term)
         xassert(tll_length(term->render.workers.queue) == 0);
     }
 
-    pixman_region32_clear(&buf->dirty);
-
     int first_dirty_row = -1;
     for (int r = 0; r < term->rows; r++) {
         struct row *row = grid_row_in_view(term->grid, r);
diff --git a/shm.c b/shm.c
index 4b503d22..ed20af3a 100644
--- a/shm.c
+++ b/shm.c
@@ -250,6 +250,7 @@ shm_get_buffer(struct wl_shm *shm, int width, int height, unsigned long cookie,
                         cookie, (void *)&it->item);
                 it->item.busy = true;
                 it->item.purge = false;
+                pixman_region32_clear(&it->item.dirty);
                 free(it->item.scroll_damage);
                 it->item.scroll_damage = NULL;
                 xassert(it->item.pix_instances == pix_instances);