git-svn: allow dcommit to retain local merge information

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>
This commit is contained in:
Eric Wong 2007-06-13 02:23:28 -07:00 коммит произвёл Junio C Hamano
Родитель 38570a47fc
Коммит 733a65aa5d
2 изменённых файлов: 152 добавлений и 9 удалений

Просмотреть файл

@ -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 $last_rev) {
@ -403,6 +396,9 @@ sub cmd_dcommit {
svn_path => '');
if (!SVN::Git::Editor->new(\%ed_opts)->apply_diff) {
print "No changes\n$d~1 == $d\n";
} elsif ($parents->{$d} && @{$parents->{$d}}) {
$gs->{inject_parents_dcommit}->{$last_rev} =
$parents->{$d};
}
}
}
@ -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;
@ -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};

Просмотреть файл

@ -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