tests: restrict cp --link inode comparisons to compatible systems

* tests/cp/link-deref.sh: On systems were cp can't determine if
gnulib linkat() emulation might create a symlink instead of a hardlink
to a symlink, copy.c will create a symlink to the symlink so that
it has more control over its metadata.  Also even if the system
supports this operation, the particular file system under test may not.
So avoid the hardlinked symlink verification in these cases.
This fixes a false failure on aix, solaris and freebsd.

diff --git a/tests/cp/link-deref.sh b/tests/cp/link-deref.sh
index c12dfc8828389dc50b265085b021f53aa080b91f..89f7a36548213eab6d07026db90fa9355b79aece 100755 (executable)
--- a/tests/cp/link-deref.sh
+++ b/tests/cp/link-deref.sh
@@ -19,6 +19,18 @@
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ cp
 
+if grep '^#define HAVE_LINKAT 1' "$CONFIG_HEADER" > /dev/null \
+   && grep '^#define LINK_FOLLOWS_SYMLINKS 0' "$CONFIG_HEADER" > /dev/null; then
+  # With this config (which is the case on GNU/Linux) cp will attempt to
+  # linkat() to hardlink a symlink.  So now see if the current file system
+  # supports this operation.
+  ln -s testtarget test_sl || framework_failure_
+  ln -P test_sl test_hl_sl || framework_failure_
+  ino_sl="$(stat -c '%i' test_sl)" || framework_failure_
+  ino_hl="$(stat -c '%i' test_hl_sl)" || framework_failure_
+  test "$ino_sl" = "$ino_hl" && can_hardlink_to_symlink=1
+fi
+
 mkdir dir              || framework_failure_
 : > file               || framework_failure_
 ln -s dir     dirlink  || framework_failure_
@@ -39,6 +51,10 @@ for src in dirlink filelink danglink; do
   typ_tgt="$(stat -c '%F' $tgt 2>/dev/null)" || typ_tgt=
 
   for o in '' -L -H -P; do
+
+    # Skip the -P case where we don't or can't hardlink symlinks
+    ! test "$can_hardlink_to_symlink" && test "$o" = '-P' && continue
+
     for r in '' -R; do
 
       command="cp --link $o $r $src dst"