testsuite: skip symlink-dirlink-basis on platforms without RESOLVE_BENEATH

secure_relative_open() has a kernel-enforced "stay below dirfd" path
on Linux 5.6+ (openat2 RESOLVE_BENEATH) and FreeBSD 13+ (openat
O_RESOLVE_BENEATH). On Solaris, OpenBSD, NetBSD, and Cygwin the code
falls back to the per-component O_NOFOLLOW walk, which by design
rejects every directory symlink in the path -- the very case this
test exercises. Mark the test skipped there rather than have it
fail with a known regression that's tracked separately.

macOS is intentionally not in the skip list: although it does not
have O_RESOLVE_BENEATH either, the test passes there in practice;
investigation of the underlying reason is left as follow-up.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

diff --git a/testsuite/symlink-dirlink-basis.test b/testsuite/symlink-dirlink-basis.test
index 9065dd81461c4e22f9060bdbf9ea60d0cea1f461..a14eb5cf595859690ff8f619f97fc5b4e37172b5 100755 (executable)
--- a/testsuite/symlink-dirlink-basis.test
+++ b/testsuite/symlink-dirlink-basis.test
@@ -26,6 +26,18 @@
 
 . "$suitedir/rsync.fns"
 
+# secure_relative_open() uses kernel-enforced "stay below dirfd" via
+# openat2(RESOLVE_BENEATH) on Linux 5.6+ and openat(O_RESOLVE_BENEATH)
+# on FreeBSD 13+. Other platforms fall back to a per-component
+# O_NOFOLLOW walk that rejects every symlink including legitimate
+# directory symlinks -- the very case this test exercises. Skip on
+# those rather than report a known failure.
+case "$(uname -s)" in
+    SunOS|OpenBSD|NetBSD|CYGWIN*)
+       test_skipped "secure_relative_open lacks RESOLVE_BENEATH equivalent on $(uname -s); issue #715 still affects this platform"
+       ;;
+esac
+
 RSYNC_RSH="$scratchdir/src/support/lsh.sh"
 export RSYNC_RSH