getumask: Make it work on native Windows.

* lib/getumask.c (getumask): When TMPDIR is unset, try TMP and TEMP.
* tests/test-getumask.c (ASSUME_UMASK_CONSTANT): Define to 1 on native
Windows.

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/getumask.c b/lib/getumask.c
index 203d6dc869..e979f9b874 100644
--- a/lib/getumask.c
+++ b/lib/getumask.c
@@ -106,6 +106,16 @@ getumask (void)
     {
       /* Create a temporary file and inspect its access permissions.  */
       const char *tmpdir = getenv ("TMPDIR");
+# if defined _WIN32 && !defined __CYGWIN__
+      if (tmpdir == NULL || *tmpdir == '\0')
+        {
+          /* On native Windows, TMPDIR is typically not set, and /tmp does not
+             exist.  $TMP and $TEMP can be used instead.  */
+          tmpdir = getenv ("TMP");
+          if (tmpdir == NULL || *tmpdir == '\0')
+            tmpdir = getenv ("TEMP");
+        }
+# endif
       if (tmpdir == NULL || *tmpdir == '\0')
         tmpdir = "/tmp";
       size_t tmpdir_length = strlen (tmpdir);