[glib/improve-win32-version-2-70: 2/2] gutils.c: Improve Windows 10/Server 2019 20H2+ detection

[Chun-wei Fan <fanchunwei src gnome org>]

commit e5917c67bac0639a8b1fe5ded3eddcc579b051d5
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Mon Nov 22 11:56:03 2021 +0800

    gutils.c: Improve Windows 10/Server 2019 20H2+ detection
    
    This improves how we obtain the Windows release versions in
    get_windows_version(), in turn g_get_os_info() for Windows 10/Server
    2019 20H2 (2009) and later and Windows 11, by doing the following:
    
    *  Check the build number for non-server versions of Windows.
       For Windows 11, the build number is 22000+, so we now correctly
       indicate on Windows 11 that we are indeed running Windows 11.
    *  Check the DisplayVersion entry in the registry under
       SOFTWARE\Microsoft\Windows NT\CurrentVersion if we obtained "2009"
       from the ReleaseId entry, since DisplayVersion replaces ReleaseId
       after Windows 10/Server 2019 20H2 (2009).  This makes things more
       clear for Windows releases after 20H2, where previously 20H2
       and 21H1 were all identified as Windows 10 [Server] 2009.
    
    This should fix issue #2443.

 glib/gutils.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 46 insertions(+), 6 deletions(-)
---
diff --git a/glib/gutils.c b/glib/gutils.c
index 4bccd7229..6f6f8d0b8 100644
--- a/glib/gutils.c
+++ b/glib/gutils.c
@@ -1298,14 +1298,35 @@ get_windows_version (gboolean with_windows)
   if (g_win32_check_windows_version (10, 0, 0, G_WIN32_OS_ANY))
     {
       gchar *win10_release;
+      gboolean is_win11 = FALSE;
 
-      g_string_append (version, "10");
+      if (!g_win32_check_windows_version (10, 0, 0, G_WIN32_OS_SERVER))
+        {
+          OSVERSIONINFOEXW osinfo;
 
-      if (!g_win32_check_windows_version (10, 0, 0, G_WIN32_OS_WORKSTATION))
-        g_string_append (version, " Server");
+          /*
+           * This always succeeds if we get here, since the
+           * g_win32_check_windows_version() already did this!
+           * We want the OSVERSIONINFOEXW here for more even
+           * fine-grained versioning items
+           */
+          _g_win32_call_rtl_version (&osinfo);
 
-      /* Windows 10 is identified by its release number, such as
-       * 1511, 1607, 1703, 1709, 1803, 1809 or 1903.
+          /*
+           * Windows 11 is actually Windows 10.0.22000+,
+           * so look at the build number
+           */
+          is_win11 = (osinfo.dwBuildNumber >= 22000);
+        }
+
+      if (is_win11)
+        g_string_append (version, "11");
+      else
+        g_string_append (version, "10");
+
+      /* Windows 10/Server 2016+ is identified by its ReleaseId or
+       * DisplayVersion (since 20H2), such as
+       * 1511, 1607, 1703, 1709, 1803, 1809 or 1903 etc.
        * The first version of Windows 10 has no release number.
        */
       win10_release = get_registry_str (HKEY_LOCAL_MACHINE,
@@ -1316,7 +1337,26 @@ get_windows_version (gboolean with_windows)
                                         L"ReleaseId");
 
       if (win10_release != NULL)
-        g_string_append_printf (version, " %s", win10_release);
+        {
+          if (g_strcmp0 (win10_release, "2009") != 0)
+            g_string_append_printf (version, " %s", win10_release);
+          else
+            {
+              g_free (win10_release);
+
+              win10_release = get_registry_str (HKEY_LOCAL_MACHINE,
+                                                L"SOFTWARE"
+                                                L"\\Microsoft"
+                                                L"\\Windows NT"
+                                                L"\\CurrentVersion",
+                                                L"DisplayVersion");
+
+              if (win10_release != NULL)
+                g_string_append_printf (version, " %s", win10_release);
+              else
+                g_string_append_printf (version, " 2009");
+            }
+        }
 
       g_free (win10_release);
     }