git@xxxxxxxxxxxxxxxxx writes:
> From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
>
> Version 8 of this patch converts the unit test to use
> perl to corrupt the index checksum (rather than altering
> a filename) and also verifies the fsck error message as
> suggested in response to v7 on the mailing list.
>
> If there are no other suggestions, I think this version
> should be considered final.
Oops. The earlier one has already been in 'master' for a few days.
Let's make this an incremental update.
Is the description in the following something you are OK with (so
that I can add your sign-off)?
Thanks.
-- >8 --
From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
Date: Tue, 25 Apr 2017 18:41:09 +0000
Subject: t1450: avoid use of "sed" on the index, which is a binary file
The previous step added a path zzzzzzzz to the index, and then used
"sed" to replace this string to yyyyyyyy to create a test case where
the checksum at the end of the file does not match the contents.
Unfortunately, use of "sed" on a non-text file is not portable.
Instead, use a Perl script that seeks to the end and modifies the
last byte of the file (where we _know_ stores the trailing
checksum).
---
t/t1450-fsck.sh | 33 ++++++++++++++++++++++++++-------
1 file changed, 26 insertions(+), 7 deletions(-)
diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index 677e15a7a4..eff1cd68e9 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -689,16 +689,35 @@ test_expect_success 'bogus head does not fallback to all heads' '
! grep $blob out
'
+# Corrupt the checksum on the index.
+# Add 1 to the last byte in the SHA.
+corrupt_index_checksum () {
+ perl -w -e '
+ use Fcntl ":seek";
+ open my $fh, "+<", ".git/index" or die "open: $!";
+ binmode $fh;
+ seek $fh, -1, SEEK_END or die "seek: $!";
+ read $fh, my $in_byte, 1 or die "read: $!";
+
+ $in_value = unpack("C", $in_byte);
+ $out_value = ($in_value + 1) & 255;
+
+ $out_byte = pack("C", $out_value);
+
+ seek $fh, -1, SEEK_END or die "seek: $!";
+ print $fh $out_byte;
+ close $fh or die "close: $!";
+ '
+}
+
+# Corrupt the checksum on the index and then
+# verify that only fsck notices.
test_expect_success 'detect corrupt index file in fsck' '
cp .git/index .git/index.backup &&
test_when_finished "mv .git/index.backup .git/index" &&
- echo zzzzzzzz >zzzzzzzz &&
- git add zzzzzzzz &&
- sed -e "s/zzzzzzzz/yyyyyyyy/" .git/index >.git/index.yyy &&
- mv .git/index.yyy .git/index &&
- # Confirm that fsck detects invalid checksum
- test_must_fail git fsck --cache &&
- # Confirm that status no longer complains about invalid checksum
+ corrupt_index_checksum &&
+ test_must_fail git fsck --cache 2>expect &&
+ grep "bad index file" expect &&
git status
'