From 0a897935ea44f062fb5fa3b6556d68815013087b Mon Sep 17 00:00:00 2001
From: Alan Griffiths <alan@octopull.co.uk>
Date: Thu, 22 Feb 2024 17:27:33 +0000
Subject: [PATCH] Ignore zero length gamma curves

---
 src/platforms/gbm-kms/server/kms/real_kms_output.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/platforms/gbm-kms/server/kms/real_kms_output.cpp b/src/platforms/gbm-kms/server/kms/real_kms_output.cpp
index d8896d2f4cf..8bef51c5c33 100644
--- a/src/platforms/gbm-kms/server/kms/real_kms_output.cpp
+++ b/src/platforms/gbm-kms/server/kms/real_kms_output.cpp
@@ -360,6 +360,12 @@ void mgg::RealKMSOutput::set_power_mode(MirPowerMode mode)
 
 void mgg::RealKMSOutput::set_gamma(mg::GammaCurves const& gamma)
 {
+    if (!gamma.red.size())
+    {
+        mir::log_warning("Ignoring attempt to set zero length gamma");
+        return;
+    }
+
     if (!ensure_crtc())
     {
         mir::log_warning("Output %s has no associated CRTC to set gamma on",