[PATCH v2 3/4] generic/452: make coping work with multi-call binary

[Andrey Albershteyn <aalbersh@kernel.org>]

On some system coreutils binaries are all symlink to the single
coreutils binary. Just copying 'ls' will not work in this setup,
especially, with the different binary name.

Add 'realpath' to find out the real binary is make it behave like an
'ls' by renaming it to 'ls'.

Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
---
 tests/generic/452     | 7 +++++--
 tests/generic/452.out | 4 ++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/tests/generic/452 b/tests/generic/452
index a19a79623489..604d978cd98c 100755
--- a/tests/generic/452
+++ b/tests/generic/452
@@ -24,8 +24,11 @@ _exclude_scratch_mount_option "noexec"
 _scratch_mkfs > $seqres.full 2>&1
 _scratch_mount >> $seqres.full 2>&1
 
-LS="$(type -P ls)"
-SCRATCH_LS=$SCRATCH_MNT/ls_on_scratch
+# Resolve full absolute path to the ls binary. This is necessary for multi-call
+# binaries. In multi-call binary setup "ls" is just a symlink to a binary (e.g.
+# coreutils) which behaves as "ls" based on the executable name (first arg $0).
+LS="$(realpath $(type -P ls))"
+SCRATCH_LS=$SCRATCH_MNT/ls
 cp $LS $SCRATCH_LS
 
 $SCRATCH_LS $SCRATCH_LS | _filter_scratch
diff --git a/tests/generic/452.out b/tests/generic/452.out
index 1d24d6b3c83a..436a01e13b09 100644
--- a/tests/generic/452.out
+++ b/tests/generic/452.out
@@ -1,3 +1,3 @@
 QA output created by 452
-SCRATCH_MNT/ls_on_scratch
-SCRATCH_MNT/ls_on_scratch
+SCRATCH_MNT/ls
+SCRATCH_MNT/ls
-- 
2.54.0