[PATCH 1/3] winex11.drv: Handle X errors from glXCopyContext().

[Zhiyi Zhang]

glxCopyContext() may throw X errors and cause the current process to exit. For example, Mesa doesn't
support glxCopyContext() for direct rendering contexts and ends up using the code path for indirect
rendering contexts. When Xorg receives such requests, it rejects them because they're for direct
rendering contexts and reports an X error. We also can't use indirect rendering context because
it needs to be explicitly enabled in xorg.conf and has poor performance. So handle this error before
graphics drivers implement the support.

Fix Cladun X2 crash at start.

Signed-off-by: Zhiyi Zhang 
---
See also https://github.com/mesa3d/mesa/blob/main/src/glx/glxcmds.c#L658 glXCopyContext() and
https://github.com/freedesktop/xorg-xserver/blob/master/glx/glxcmds.c#L843 __glXDisp_CopyContext().

dlls/winex11.drv/opengl.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/dlls/winex11.drv/opengl.c b/dlls/winex11.drv/opengl.c
index 92555841f71..fd6eea05fa6 100644
--- a/dlls/winex11.drv/opengl.c
+++ b/dlls/winex11.drv/opengl.c
@@ -1703,9 +1703,21 @@ static BOOL WINAPI glxdrv_wglCopyContext(struct wgl_context *src, struct wgl_con
 {
     TRACE("%p -> %p mask %#x\n", src, dst, mask);

-    pglXCopyContext(gdi_display, src->ctx, dst->ctx, mask);
+    X11DRV_expect_error( gdi_display, GLXErrorHandler, NULL );
+    pglXCopyContext( gdi_display, src->ctx, dst->ctx, mask );
+    XSync( gdi_display, False );
+    if (X11DRV_check_error())
+    {
+        static unsigned int once;
+
+        if (!once++)
+        {
+            ERR("glXCopyContext failed. glXCopyContext() for direct rendering contexts not "
+                "implemented in the host graphics driver?\n");
+        }
+        return FALSE;
+    }

-    /* As opposed to wglCopyContext, glXCopyContext doesn't return anything, so hopefully we passed */
     return TRUE;
 }