[PATCH 0/1] MR7769: ntdll: correctly detect the NUL device under macOS

[John Szakmeister (＠jszakmeister)]

macOS doesn't have a way to detect this via the FIODTYPE ioctl(), so we have to resort to detecting
the NUL device via major and minor version number.  Fortunately, that hasn't changed since the
inception of macOS.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55568

[PATCH 1/1] ntdll: correctly detect the NUL device under macOS

[John Szakmeister]

From: John Szakmeister

macOS doesn't have a way to detect this via the FIODTYPE ioctl(), so we have to resort to detecting
the NUL device via major and minor version number.  Fortunately, that hasn't changed since the
inception of macOS.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55568
---
 dlls/ntdll/unix/file.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/dlls/ntdll/unix/file.c b/dlls/ntdll/unix/file.c
index a475fcc3225..e64c0e51e52 100644
--- a/dlls/ntdll/unix/file.c
+++ b/dlls/ntdll/unix/file.c
@@ -6772,6 +6772,14 @@ NTSTATUS get_device_info( int fd, FILE_FS_DEVICE_INFORMATION *info )
             break;
         }
 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__APPLE__)
+#if defined(__APPLE__)
+        /* /dev/null on has been 3, 2 since the start of OSX */
+        if (major(st.st_rdev) == 3 && minor(st.st_rdev) == 2)
+        {
+            info->DeviceType = FILE_DEVICE_NULL;
+        }
+        else
+#endif
         {
             int d_type;
             if (ioctl(fd, FIODTYPE, &d_type) == 0)

[John Szakmeister (＠jszakmeister)]

I thought about possibly writing a test for macOS that would fail if the major/minor device number of `/dev/null` ever changed.  Didn't know if the project would want something like that, and where to put it if it does. :-)