From 25ae15694488fcb23f03a067d12c318550f24010 Mon Sep 17 00:00:00 2001
From: sfan5 <sfan5@live.de>
Date: Sat, 9 Jul 2022 22:04:51 +0200
Subject: [PATCH] Fix CreateContextAttribsARB fallback behaviour

fixes minetest/minetest#12518
---
 source/Irrlicht/CGLXManager.cpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/source/Irrlicht/CGLXManager.cpp b/source/Irrlicht/CGLXManager.cpp
index a72b6a8..8b6c66f 100644
--- a/source/Irrlicht/CGLXManager.cpp
+++ b/source/Irrlicht/CGLXManager.cpp
@@ -311,6 +311,16 @@ void CGLXManager::destroySurface()
 		glXDestroyWindow((Display*)CurrentContext.OpenGLLinux.X11Display, GlxWin);
 }
 
+#if defined(GLX_ARB_create_context)
+static int IrrIgnoreError(Display *display, XErrorEvent *event)
+{
+	char msg[256];
+	XGetErrorText(display, event->error_code, msg, 256);
+	os::Printer::log("Ignoring an X error", msg, ELL_DEBUG);
+	return 0;
+}
+#endif
+
 bool CGLXManager::generateContext()
 {
 	GLXContext context = 0;
@@ -329,13 +339,16 @@ bool CGLXManager::generateContext()
 
 			if (glxCreateContextAttribsARB)
 			{
+				os::Printer::log("GLX with GLX_ARB_create_context", ELL_DEBUG);
 				int contextAttrBuffer[] = {
 					GLX_CONTEXT_MAJOR_VERSION_ARB, 3,
 					GLX_CONTEXT_MINOR_VERSION_ARB, 0,
 					// GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB,
 					None
 				};
+				XErrorHandler old = XSetErrorHandler(IrrIgnoreError);
 				context = glxCreateContextAttribsARB((Display*)CurrentContext.OpenGLLinux.X11Display, (GLXFBConfig)glxFBConfig, NULL, True, contextAttrBuffer);
+				XSetErrorHandler(old);
 				// transparently fall back to legacy call
 			}
 			if (!context)