[gtk/gtk-3-24] Update Quartz version detection for macOS 12.

[John Ralls <jralls src gnome org>]

commit a752e338381bc37dbe8d4c04ec23e4f6fd911b30
Author: John Ralls <jralls ceridwen us>
Date:   Wed Sep 8 18:01:50 2021 -0700

    Update Quartz version detection for macOS 12.

 gdk/quartz/gdkglobals-quartz.c | 16 +++++++---------
 gdk/quartz/gdkquartz.h         |  3 ++-
 2 files changed, 9 insertions(+), 10 deletions(-)
---
diff --git a/gdk/quartz/gdkglobals-quartz.c b/gdk/quartz/gdkglobals-quartz.c
index 72aed1c92d..30649efe8a 100644
--- a/gdk/quartz/gdkglobals-quartz.c
+++ b/gdk/quartz/gdkglobals-quartz.c
@@ -29,28 +29,26 @@ GdkWindow *_gdk_root = NULL;
 GdkOSXVersion
 gdk_quartz_osx_version (void)
 {
-  static gint32 minor = GDK_OSX_UNSUPPORTED;
+  static gint32 vkey = GDK_OSX_UNSUPPORTED;
 
-  if (minor == GDK_OSX_UNSUPPORTED)
+  if (vkey == GDK_OSX_UNSUPPORTED)
     {
 #if MAC_OS_X_VERSION_MIN_REQUIRED < 101000
-      OSErr err = Gestalt (gestaltSystemVersionMinor, (SInt32*)&minor);
+      OSErr err = Gestalt (gestaltSystemVersionMinor, (SInt32*)&vkey);
 
       g_return_val_if_fail (err == noErr, GDK_OSX_UNSUPPORTED);
 #else
       NSOperatingSystemVersion version;
 
       version = [[NSProcessInfo processInfo] operatingSystemVersion];
-      minor = version.minorVersion;
-      if (version.majorVersion == 11)
-        minor += 16;
+      vkey = version.majorVersion == 10 ? version.minorVersion : version.majorVersion + 5;
 #endif
     }
 
-  if (minor < GDK_OSX_MIN)
+  if (vkey < GDK_OSX_MIN)
     return GDK_OSX_UNSUPPORTED;
-  else if (minor > GDK_OSX_CURRENT)
+  else if (vkey > GDK_OSX_CURRENT)
     return GDK_OSX_NEW;
   else
-    return minor;
+    return vkey;
 }
diff --git a/gdk/quartz/gdkquartz.h b/gdk/quartz/gdkquartz.h
index dd1b4f41af..2d53dcbce6 100644
--- a/gdk/quartz/gdkquartz.h
+++ b/gdk/quartz/gdkquartz.h
@@ -42,7 +42,8 @@ typedef enum
   GDK_OSX_MOJAVE = 14,
   GDK_OSX_CATALINA = 15,
   GDK_OSX_BIGSUR = 16,
-  GDK_OSX_CURRENT = 15,
+  GDK_OSX_MONTEREY = 17,
+  GDK_OSX_CURRENT = 17,
   GDK_OSX_NEW = 99
 } GdkOSXVersion;