File U_xwayland-Update-screen-pixmap-on-output-resize.patch of Package xorg-x11-server.16781

From 44c693f45d6abd6f7f3bd2f756d35811db143af7 Mon Sep 17 00:00:00 2001
From: Olivier Fourdan <ofourdan@redhat.com>
Date: Fri, 28 Jun 2019 16:55:11 +0200
Subject: [PATCH] xwayland: Update screen pixmap on output resize
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Running Xwayland non-rootless and resizing the output would lead to a
crash while trying to update the larger areas of the root window.

Make sure we resize the backing pixmap according to the new output size
to avoid the crash.

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Closes: https://gitlab.freedesktop.org/xorg/xserver/issues/834
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
(cherry picked from commit ce9455b5ee389b100a9b7da76b79690d97211b7a)
---
 hw/xwayland/xwayland-output.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/hw/xwayland/xwayland-output.c b/hw/xwayland/xwayland-output.c
index cc68f0340..9d33ed862 100644
--- a/hw/xwayland/xwayland-output.c
+++ b/hw/xwayland/xwayland-output.c
@@ -171,6 +171,40 @@ approximate_mmpd(struct xwl_screen *xwl_screen)
         return 25.4 / DEFAULT_DPI;
 }
 
+static int
+xwl_set_pixmap_visit_window(WindowPtr window, void *data)
+{
+    ScreenPtr screen = window->drawable.pScreen;
+
+    if (screen->GetWindowPixmap(window) == data) {
+        screen->SetWindowPixmap(window, screen->GetScreenPixmap(screen));
+        return WT_WALKCHILDREN;
+    }
+
+    return WT_DONTWALKCHILDREN;
+}
+
+static void
+update_backing_pixmaps(struct xwl_screen *xwl_screen, int width, int height)
+{
+    ScreenPtr pScreen = xwl_screen->screen;
+    WindowPtr pRoot = pScreen->root;
+    PixmapPtr old_pixmap, new_pixmap;
+
+    old_pixmap = pScreen->GetScreenPixmap(pScreen);
+    new_pixmap = pScreen->CreatePixmap(pScreen, width, height,
+                                       pScreen->rootDepth,
+                                       CREATE_PIXMAP_USAGE_BACKING_PIXMAP);
+    pScreen->SetScreenPixmap(new_pixmap);
+
+    if (old_pixmap) {
+        TraverseTree(pRoot, xwl_set_pixmap_visit_window, old_pixmap);
+        pScreen->DestroyPixmap(old_pixmap);
+    }
+
+    pScreen->ResizeWindow(pRoot, 0, 0, width, height, NULL);
+}
+
 static void
 update_screen_size(struct xwl_output *xwl_output, int width, int height)
 {
@@ -180,6 +214,9 @@ update_screen_size(struct xwl_output *xwl_output, int width, int height)
     if (xwl_screen->root_clip_mode == ROOT_CLIP_FULL)
         SetRootClip(xwl_screen->screen, ROOT_CLIP_NONE);
 
+    if (!xwl_screen->rootless && xwl_screen->screen->root)
+        update_backing_pixmaps (xwl_screen, width, height);
+
     xwl_screen->width = width;
     xwl_screen->height = height;
     xwl_screen->screen->width = width;
-- 
2.16.4