Re: [PATCH] t2080: fix cp invocation to copy symlinks instead of following them

On Thu, May 27 2021, Ævar Arnfjörð Bjarmason wrote:

On Wed, May 26 2021, Matheus Tavares wrote:

quoted

t2080 makes a few copies of a test repository and later performs a
branch switch on each one of the copies to verify that parallel checkout
and sequential checkout produce the same results. However, the
repository is copied with `cp -R` which, on some systems, defaults to
following symlinks on the directory hierarchy and copying their target
files instead of copying the symlinks themselves. AIX is one example of
system where this happens. Because the symlinks are not preserved, the
copied repositories have paths that do not match what is in the index,
causing git to abort the checkout operation that we want to test. This
makes the test fail on these systems.

Fix this by copying the repository with the POSIX flag '-P', which
forces cp to copy the symlinks instead of following them. Note that we
already use this flag for other cp invocations in our test suite (see
t7001). With this change, t2080 now passes on AIX.

Reported-by: Ævar Arnfjörð Bjarmason <redacted>
Signed-off-by: Matheus Tavares <redacted>
---
 t/t2080-parallel-checkout-basics.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/t2080-parallel-checkout-basics.sh b/t/t2080-parallel-checkout-basics.sh
index 7087818550..3e0f8c675f 100755
--- a/t/t2080-parallel-checkout-basics.sh
+++ b/t/t2080-parallel-checkout-basics.sh

@@ -114,7 +114,7 @@ do
 
 	test_expect_success "$mode checkout" '
 		repo=various_$mode &&
-		cp -R various $repo &&
+		cp -R -P various $repo &&
 
 		# The just copied files have more recent timestamps than their
 		# associated index entries. So refresh the cached timestamps

Thanks for the quick fix, I can confirm that this makes the test pass on
AIX 7.2.

There's still a failure[1] in t2082-parallel-checkout-attributes.sh
though, which is new in 2.32.0-rc*. The difference is in an unexpected
BOM:
    
    avar@gcc119:[/scratch/avar/git/t]perl -nle 'print unpack "H*"' trash\ directory.t2082-parallel-checkout-attributes/encoding/A.internal 
    efbbbf74657874
    avar@gcc119:[/scratch/avar/git/t]perl -nle 'print unpack "H*"' trash\ directory.t2082-parallel-checkout-attributes/encoding/utf8-text  
    74657874

I.e. the A.internal starts with 0xefbbbf. The 2nd test of t0028*.sh also
fails similarly[2], so perhaps it's some old/iconv/whatever issue not
per-se related to any change of yours.

I tried compiling with both NO_ICONV=Y and ICONV_OMITS_BOM=Y, both have
the same failure.

In any case, I think AIX test failures (or other obscure platforms I
test) are rather uninteresting per-se, I mainly test on these to smoke
out bad assumptions elsewhere. E.g. non-POSIX code, perhaps in this case
we're relying on some unportable iconv assumption, or maybe not...
    

1.
Initialized empty Git repository in /scratch/avar/git/t/trash directory.t2082-parallel-checkout-attributes/encoding/.git/
+ cd encoding
+ echo text
+ 1> utf8-text
+ write_utf16
+ 0< utf8-text 1> utf16-text
checking prerequisite: NO_UTF16_BOM

mkdir -p "$TRASH_DIRECTORY/prereq-test-dir-NO_UTF16_BOM" &&
(
        cd "$TRASH_DIRECTORY/prereq-test-dir-NO_UTF16_BOM" &&
        test $(printf abc | iconv -f UTF-8 -t UTF-16 | wc -c) = 6

)
+ mkdir -p /scratch/avar/git/t/trash directory.t2082-parallel-checkout-attributes/prereq-test-dir-NO_UTF16_BOM
+ cd /scratch/avar/git/t/trash directory.t2082-parallel-checkout-attributes/prereq-test-dir-NO_UTF16_BOM
+ printf abc
+ iconv -f UTF-8 -t UTF-16
+ wc -c
+ test 6 = 6
prerequisite NO_UTF16_BOM ok
+ echo A working-tree-encoding=UTF-16
+ 1> .gitattributes
+ cp utf16-text A
+ cp utf8-text B
+ git add A B .gitattributes
+ git commit -m encoding
[master (root-commit) 65fa7e8] encoding
 Author: A U Thor [off-list ref]
 3 files changed, 3 insertions(+)
 create mode 100644 .gitattributes
 create mode 100644 A
 create mode 100644 B
+ git cat-file -p :A
+ 1> A.internal
+ test_cmp_bin utf8-text A.internal
utf8-text A.internal differ: char 1, line 1
error: last command exited with $?=1
not ok 2 - parallel-checkout with re-encoding
#
#               set_checkout_config 2 0 &&
#               git init encoding &&
#               (
#                       cd encoding &&
#                       echo text >utf8-text &&
#                       write_utf16 <utf8-text >utf16-text &&
#
#                       echo "A working-tree-encoding=UTF-16" >.gitattributes &&
#                       cp utf16-text A &&
#                       cp utf8-text B &&
#                       git add A B .gitattributes &&
#                       git commit -m encoding &&
#
#                       # Check that A is stored in UTF-8
#                       git cat-file -p :A >A.internal &&
#                       test_cmp_bin utf8-text A.internal &&
#
#                       rm A B &&
#                       test_checkout_workers 2 git checkout A B &&
#
#                       # Check that A (and only A) is re-encoded during checkout
#                       test_cmp_bin utf16-text A &&
#                       test_cmp_bin utf8-text B
#               )
#

2. 

avar@gcc119:[/scratch/avar/git/t]perl -nle 'print unpack "H*"' trash\ directory.t0028-working-tree-encoding/test.utf8.raw  
68616c6c6f20746865726521
63616e20796f752072656164206d653f
avar@gcc119:[/scratch/avar/git/t]perl -nle 'print unpack "H*"' trash\ directory.t0028-working-tree-encoding/test.utf16.git    
efbbbf68616c6c6f20746865726521
63616e20796f752072656164206d653f