Skip to content

Commit

Permalink
git-svn: allow dcommit to retain local merge information
Browse files Browse the repository at this point in the history 
dcommit will still rewrite the HEAD commit and the history of the first
parents of each HEAD~1, HEAD~2, HEAD~3 as it always has.

However, any merge parents (HEAD^2, HEAD^^2, HEAD~2^2) will now be
preserved when the new HEAD and HEAD~[0-9]+ commits are rewritten to SVN
with dcommit.  Commits written to SVN will still not have any merge
information besides anything in the commit message.

Thanks to Joakim Tjernlund, Junio C Hamano and Steven Grimm
for explanations, feedback, examples and test case.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
  • Loading branch information
Eric Wong authored and Junio C Hamano committed Jun 13, 2007
1 parent 38570a4 commit 733a65a
Show file tree
Hide file tree
Showing 2 changed files with 152 additions and 9 deletions.
72 changes: 63 additions & 9 deletions git-svn.perl
View file
Original file line number Diff line number Diff line change
Expand Up @@ -372,16 +372,9 @@ sub cmd_dcommit {
die "Unable to determine upstream SVN information from ",
"$head history\n";
}
my $c = $refs[-1];
my $last_rev;
foreach my $d (@refs) {
if (!verify_ref("$d~1")) {
fatal "Commit $d\n",
"has no parent commit, and therefore ",
"nothing to diff against.\n",
"You should be working from a repository ",
"originally created by git-svn\n";
}
my ($linear_refs, $parents) = linearize_history($gs, \@refs);
foreach my $d (@$linear_refs) {
unless (defined $last_rev) {
(undef, $last_rev, undef) = cmt_metadata("$d~1");
unless (defined $last_rev) {
Expand All @@ -403,6 +396,9 @@ sub cmd_dcommit {
svn_path => '');
if (!SVN::Git::Editor->new(\%ed_opts)->apply_diff) {
print "No changes\n$d~1 == $d\n";
} elsif ($parents->{$d} && @{$parents->{$d}}) {
$gs->{inject_parents_dcommit}->{$last_rev} =
$parents->{$d};
}
}
}
Expand Down Expand Up @@ -821,6 +817,59 @@ sub working_head_info {
(undef, undef, undef, undef);
}

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
}

sub linearize_history {
my ($gs, $refs) = @_;
my %parents;
foreach my $c (@$refs) {
read_commit_parents(\%parents, $c);
}

my @linear_refs;
my %skip = ();
my $last_svn_commit = $gs->last_commit;
foreach my $c (reverse @$refs) {
next if $c eq $last_svn_commit;
last if $skip{$c};

unshift @linear_refs, $c;
$skip{$c} = 1;

# we only want the first parent to diff against for linear
# history, we save the rest to inject when we finalize the
# svn commit
my $fp_a = verify_ref("$c~1");
my $fp_b = shift @{$parents{$c}} if $parents{$c};
if (!$fp_a || !$fp_b) {
die "Commit $c\n",
"has no parent commit, and therefore ",
"nothing to diff against.\n",
"You should be working from a repository ",
"originally created by git-svn\n";
}
if ($fp_a ne $fp_b) {
die "$c~1 = $fp_a, however parsing commit $c ",
"revealed that:\n$c~1 = $fp_b\nBUG!\n";
}

foreach my $p (@{$parents{$c}}) {
$skip{$p} = 1;
}
}
(\@linear_refs, \%parents);
}

package Git::SVN;
use strict;
use warnings;
Expand Down Expand Up @@ -1541,6 +1590,11 @@ sub get_commit_parents {
if (my $cur = ::verify_ref($self->refname.'^0')) {
push @tmp, $cur;
}
if (my $ipd = $self->{inject_parents_dcommit}) {
if (my $commit = delete $ipd->{$log_entry->{revision}}) {
push @tmp, @$commit;
}
}
push @tmp, $_ foreach (@{$log_entry->{parents}}, @tmp);
while (my $p = shift @tmp) {
next if $seen{$p};
Expand Down
89 changes: 89 additions & 0 deletions t/t9114-git-svn-dcommit-merge.sh
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,89 @@
#!/bin/sh
#
# Copyright (c) 2007 Eric Wong
# Based on a script by Joakim Tjernlund <joakim.tjernlund@transmode.se>

test_description='git-svn dcommit handles merges'

. ./lib-git-svn.sh

big_text_block () {
cat << EOF
#
# (C) Copyright 2000 - 2005
# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
#
# See file CREDITS for list of people who contributed to this
# project.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 2 of
# the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
# MA 02111-1307 USA
#
EOF
}

test_expect_success 'setup svn repository' "
svn co $svnrepo mysvnwork &&
mkdir -p mysvnwork/trunk &&
cd mysvnwork &&
big_text_block >> trunk/README &&
svn add trunk &&
svn ci -m 'first commit' trunk &&
cd ..
"

test_expect_success 'setup git mirror and merge' "
git svn init $svnrepo -t tags -T trunk -b branches &&
git svn fetch &&
git checkout --track -b svn remotes/trunk &&
git checkout -b merge &&
echo new file > new_file &&
git add new_file &&
git commit -a -m 'New file' &&
echo hello >> README &&
git commit -a -m 'hello' &&
echo add some stuff >> new_file &&
git commit -a -m 'add some stuff' &&
git checkout svn &&
mv -f README tmp &&
echo friend > README &&
cat tmp >> README &&
git commit -a -m 'friend' &&
git pull . merge
"

test_debug 'gitk --all & sleep 1'

test_expect_success 'verify pre-merge ancestry' "
test x\`git rev-parse --verify refs/heads/svn^2\` = \
x\`git rev-parse --verify refs/heads/merge\` &&
git cat-file commit refs/heads/svn^ | grep '^friend$'
"

test_expect_success 'git svn dcommit merges' "
git svn dcommit
"

test_debug 'gitk --all & sleep 1'

test_expect_success 'verify post-merge ancestry' "
test x\`git rev-parse --verify refs/heads/svn\` = \
x\`git rev-parse --verify refs/remotes/trunk \` &&
test x\`git rev-parse --verify refs/heads/svn^2\` = \
x\`git rev-parse --verify refs/heads/merge\` &&
git cat-file commit refs/heads/svn^ | grep '^friend$'
"

test_done

0 comments on commit 733a65a

Please sign in to comment.