From db0da823f55734baf4c1e4de680e7091f33aac17 Mon Sep 17 00:00:00 2001
From: Matthieu Herrb <matthieu.herrb@laas.fr>
Date: Sun, 31 Oct 2021 11:28:28 +0100
Subject: [PATCH] Make xf86CompatOutput() return NULL when there are no
 privates

Some drivers (mach64 w/o DRI for instance) don't initialize privates.

Signed-off-by: Matthieu Herrb <matthieu.herrb@laas.fr>
(cherry picked from commit 80eeff3ebac772e25c9107199989e677457dbe06)
---
 hw/xfree86/modes/xf86Crtc.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/xfree86/modes/xf86Crtc.h b/hw/xfree86/modes/xf86Crtc.h
index fcba5c902..7a562874c 100644
--- a/hw/xfree86/modes/xf86Crtc.h
+++ b/hw/xfree86/modes/xf86Crtc.h
@@ -839,6 +839,9 @@ xf86CompatOutput(ScrnInfoPtr pScrn)
 {
     xf86CrtcConfigPtr config = XF86_CRTC_CONFIG_PTR(pScrn);
 
+    if (xf86CrtcConfigPrivateIndex == -1)
+        return NULL;
+
     if (config->compat_output < 0)
         return NULL;
     return config->output[config->compat_output];