Brendan Shanks : winemac.drv: Fix crash when building against Metal-capable SDK but running on older OS X.

[Alexandre Julliard]

Module: wine
Branch: stable
Commit: cb9b17fa856dd8c43a52077598088688fcb917f4
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=cb9b17fa856dd8c43a52077598088688fcb917f4

Author: Brendan Shanks <bshanks at codeweavers.com>
Date:   Wed Mar 10 15:25:20 2021 -0800

winemac.drv: Fix crash when building against Metal-capable SDK but running on older OS X.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=50790
Signed-off-by: Brendan Shanks <bshanks at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>
(cherry picked from commit d52c4eb00ca0a0374bef81a1d794026f41399b19)
Signed-off-by: Michael Stefaniuc <mstefani at winehq.org>

---

 dlls/winemac.drv/cocoa_display.m | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/dlls/winemac.drv/cocoa_display.m b/dlls/winemac.drv/cocoa_display.m
index 2e50b67c7d1..dfd70f10792 100644
--- a/dlls/winemac.drv/cocoa_display.m
+++ b/dlls/winemac.drv/cocoa_display.m
@@ -343,10 +343,15 @@ static int macdrv_get_gpu_info_from_display_id_using_metal(struct macdrv_gpu* gp
     int ret = -1;
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
 
+    /* Test if Metal is available */
+    if (&CGDirectDisplayCopyCurrentMetalDevice == NULL)
+        goto done;
+
     device = [CGDirectDisplayCopyCurrentMetalDevice(display_id) autorelease];
     if (device && [device respondsToSelector:@selector(registryID)])
         ret = macdrv_get_gpu_info_from_registry_id(gpu, device.registryID);
 
+done:
     [pool release];
     return ret;
 }