Use the rev-list --parents functionality to read the parents
of the commit. cat-file only shows the raw object with the
original parents and doesn't take into account grafts; so
we'll rely on rev-list machinery for the smarts here.
Signed-off-by: Eric Wong <normalperson@xxxxxxxx>
---
Junio C Hamano <gitster@xxxxxxxxx> wrote:
> "Joakim Tjernlund" <joakim.tjernlund@xxxxxxxxxxxx> writes:
>
> > hmm, I think git-cat-file is to blame.
> > git-cat-file commit da783cce390ce013b19f1d308ea6813269c6a6b5 does
> > not list list any parent...
>
> The plumbing cat-file does not deal with grafts and this is
> deliberate. Otherwise you would not be able to find the true
> set of parents when you'd want to.
>
> So do not blame cat-file, but blame the Porcelain that uses
> cat-file to read a commit object, without annotating what it
> read with what is in grafts, in this case your command line
> experiment ;-).
>
> The log family of commands and rev-list plumbing while
> traversing commit ancestry chain do take grafts into account.
>
> One caveat is pretty=raw output format shows true parents
> without grafts on "parent " header line, while the "commit "
> fake header prepended in the output for each commit shows the
> parents that takes into account.
>
> To illustrate, if you forge the history and say the parent of
> 1ddea77 is 5da1606 (when the true parent is 820eca68) with
> grafts mechanism, here is what happens:
>
> $ echo '1ddea77e449ef28d8a7c74521af21121ab01abc0 5da1606d0bf5b970fadfa0ca91618a1e871f6755' >.git/info/grafts
> $ git show -s --pretty=raw --parents 1ddea77
> commit 1ddea77e449ef28d8a7c74521af21121ab01abc0 5da1606d0bf5b970fadfa0ca91618a1e871f6755
> tree e9e61bc801438062978ff47b0963c536ed1e51a9
> parent 820eca68c2577d7499d203d7f4f7ae479b577683
> author Nick Hengeveld <nickh@xxxxxxxxxxxx> 1127757131 -0700
> committer Junio C Hamano <junkio@xxxxxxx> 1127805558 -0700
>
> [PATCH] Return CURL error message when object transfer fails
>
> Return CURL error message when object transfer fails
> ...
Interesting. I didn't know about the --parents option before.
git-svn.perl | 11 +++--------
1 files changed, 3 insertions(+), 8 deletions(-)
diff --git a/git-svn.perl b/git-svn.perl
index fbd4691..f818160 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -841,14 +841,9 @@ sub working_head_info {
sub read_commit_parents {
my ($parents, $c) = @_;
- my ($fh, $ctx) = command_output_pipe(qw/cat-file commit/, $c);
- while (<$fh>) {
- chomp;
- last if '';
- /^parent ($sha1)/ or next;
- push @{$parents->{$c}}, $1;
- }
- close $fh; # break the pipe
+ chomp(my $p = command_oneline(qw/rev-list --parents -1/, $c));
+ $p =~ s/^($c)\s*// or die "rev-list --parents -1 $c failed!\n";
+ @{$parents->{$c}} = split(/ /, $p);
}
sub linearize_history {
--
Eric Wong
-
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