git: 5e96f4006d2e - main - opendir: Simplify is_unionstack().

The branch main has been updated by des:

URL: https://cgit.FreeBSD.org/src/commit/?id=5e96f4006d2e5f165531a53b6c1393a1c7604f42

commit 5e96f4006d2e5f165531a53b6c1393a1c7604f42
Author:     Dag-Erling Smørgrav <des@FreeBSD.org>
AuthorDate: 2025-07-02 10:22:21 +0000
Commit:     Dag-Erling Smørgrav <des@FreeBSD.org>
CommitDate: 2025-07-02 10:22:29 +0000

    opendir: Simplify is_unionstack().
    
    Sponsored by:   Klara, Inc.
    Reviewed by:    imp
    Differential Revision:  https://reviews.freebsd.org/D51118
---
 lib/libc/gen/opendir2.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/lib/libc/gen/opendir2.c b/lib/libc/gen/opendir2.c
index 30a9030693e4..b9ac23e6d9fd 100644
--- a/lib/libc/gen/opendir2.c
+++ b/lib/libc/gen/opendir2.c
@@ -243,20 +243,18 @@ _filldir(DIR *dirp, bool use_current_pos)
 	return (true);
 }
 
+/*
+ * Return true if the file descriptor is associated with a file from a
+ * union file system or from a file system mounted with the union flag.
+ */
 static bool
 is_unionstack(int fd)
 {
-	int unionstack;
-
-	unionstack = _fcntl(fd, F_ISUNIONSTACK, 0);
-	if (unionstack != -1)
-		return (unionstack);
-
 	/*
-	 * Should not happen unless running on a kernel without the op,
-	 * but no use rendering the system useless in such a case.
+	 * This call shouldn't fail, but if it does, just assume that the
+	 * answer is no.
 	 */
-	return (0);
+	return (_fcntl(fd, F_ISUNIONSTACK, 0) > 0);
 }
 
 /*