From 751e631e1c9965e90e972f427c2a008cebed442e Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Fri, 17 Apr 2026 14:39:24 +1000
Subject: [PATCH] Xext/vidmode: fix SProcVidModeSwitchToMode swapping only
 screen field

SProcVidModeSwitchToMode() only byte-swapped the screen field (CARD32)
from the 52-byte xXF86VidModeSwitchToModeReq struct. All other fields
were passed to ProcVidModeSwitchToMode unswapped.

This implements full swapping, including the pre-v2 version because how
could we have lived without that for so long...

SwapRestL is not technically needed but added for consistency with other
request handlers.

Co-Authored-by: Claude Code <noreply@anthropic.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2181>
---
 Xext/vidmode.c | 40 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 2 deletions(-)

diff --git a/Xext/vidmode.c b/Xext/vidmode.c
index 04010eb11..9b5322237 100644
--- a/Xext/vidmode.c
+++ b/Xext/vidmode.c
@@ -1910,9 +1910,45 @@ SProcVidModeSwitchMode(ClientPtr client)
 static int _X_COLD
 SProcVidModeSwitchToMode(ClientPtr client)
 {
+    xXF86OldVidModeSwitchToModeReq *oldstuff =
+        (xXF86OldVidModeSwitchToModeReq *) client->requestBuffer;
+    int ver;
+
     REQUEST(xXF86VidModeSwitchToModeReq);
-    REQUEST_SIZE_MATCH(xXF86VidModeSwitchToModeReq);
-    swapl(&stuff->screen);
+    ver = ClientMajorVersion(client);
+    if (ver < 2) {
+        REQUEST_AT_LEAST_SIZE(xXF86OldVidModeSwitchToModeReq);
+        swapl(&oldstuff->screen);
+        swapl(&oldstuff->dotclock);
+        swaps(&oldstuff->hdisplay);
+        swaps(&oldstuff->hsyncstart);
+        swaps(&oldstuff->hsyncend);
+        swaps(&oldstuff->htotal);
+        swaps(&oldstuff->vdisplay);
+        swaps(&oldstuff->vsyncstart);
+        swaps(&oldstuff->vsyncend);
+        swaps(&oldstuff->vtotal);
+        swapl(&oldstuff->flags);
+        swapl(&oldstuff->privsize);
+        SwapRestL(oldstuff);
+    }
+    else {
+        REQUEST_AT_LEAST_SIZE(xXF86VidModeSwitchToModeReq);
+        swapl(&stuff->screen);
+        swapl(&stuff->dotclock);
+        swaps(&stuff->hdisplay);
+        swaps(&stuff->hsyncstart);
+        swaps(&stuff->hsyncend);
+        swaps(&stuff->htotal);
+        swaps(&stuff->hskew);
+        swaps(&stuff->vdisplay);
+        swaps(&stuff->vsyncstart);
+        swaps(&stuff->vsyncend);
+        swaps(&stuff->vtotal);
+        swapl(&stuff->flags);
+        swapl(&stuff->privsize);
+        SwapRestL(stuff);
+    }
     return ProcVidModeSwitchToMode(client);
 }