Re: [PATCH] difftool: fix dir-diff when file does not exist in working tree
- From
Junio C Hamano <gitster@pobox.com>
- Date
- May 17, 2013, 18:10 UTC
- Message-ID
- <7v38tlzdcv.fsf@alter.siamese.dyndns.org>
- In-Reply-To
- <de6690bea81de561747ca49893fbc77fa3eb8529.1368811736.git.john@keeping.me.uk>
John Keeping <john@keeping.me.uk> writes:
Show 30 quoted lines
> Commit 02c5631 (difftool --dir-diff: symlink all files matching the
> working tree, 2013-03-14) does not handle the case where a file that is
> being compared does not exist in the working tree. Fix this by checking
> for existence explicitly before running git-hash-object.
>
> Reported-by: Kevin Bracey <kevin@bracey.fi>
> Signed-off-by: John Keeping <john@keeping.me.uk>
> ---
> This fixes a regression in 1.8.3-rc0.
>
> git-difftool.perl | 9 ++++++++-
> t/t7800-difftool.sh | 7 +++++++
> 2 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/git-difftool.perl b/git-difftool.perl
> index 6780292..0a1cb0a 100755
> --- a/git-difftool.perl
> +++ b/git-difftool.perl
> @@ -92,7 +92,14 @@ sub use_wt_file
> return 0;
> }
>
> - my $wt_sha1 = $repo->command_oneline('hash-object', "$workdir/$file");
> + my $wt_sha1;
> + if (-e "$workdir/$file") {
> + $wt_sha1 = $repo->command_oneline('hash-object', "$workdir/$file");
> + } else {
> + # If the file doesn't exist in the working tree, use something
> + # that cannot match a SHA-1.
> + $wt_sha1 = '';Yuck.
"that cannot match" might be a good justification to say "this does not break the next line to set $use and forces it to false", but "when we return false in $use, the value of $wt_sha1 is not used" needs to be said to convince why this is a safe change.
But if $sha1 is $null_sha1, we do end up setting $use to true and the caller would stuff the empty $wt_sha1 to form:
$wtindex .= "$rmode \$dst_path\0";
Is that what we want to do here, or is it a "will never happen" condition? If the latter, the reason need to be described in this comment (and in the log).
Thanks.
Show 22 quoted lines
> + }; > my $use = ($sha1 eq $null_sha1) || ($sha1 eq $wt_sha1); > return ($use, $wt_sha1); > } > diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh > index a6bd99e..d46f041 100755 > --- a/t/t7800-difftool.sh > +++ b/t/t7800-difftool.sh > @@ -356,6 +356,13 @@ run_dir_diff_test 'difftool --dir-diff from subdirectory' ' > ) > ' > > +run_dir_diff_test 'difftool --dir-diff when worktree file is missing' ' > + test_when_finished git reset --hard && > + rm file2 && > + git difftool --dir-diff $symlinks --extcmd ls branch master >output && > + grep file2 output > +' > + > write_script .git/CHECK_SYMLINKS <<\EOF > for f in file file2 sub/sub > do