git - SVN转Git时如何修改提交信息？

Question

我目前正在 Github 上镜像一个现有的 SVN 存储库。对于初始克隆，我这样做了:

git svn --authors-prog=fixsvnauthors clone http://closure-compiler.googlecode.com/svn/

为了每小时更新一次 repo，我这样做了:

git svn --authors-prog=fixsvnauthors rebase

fixsvnauthors 将 SVN 用户名(电子邮件地址)映射到 Git 用户名。我现在的问题是这个 SVN 存储库似乎对提交消息有一个奇怪的策略。他们中的大多数以空行开头。 Github 根本不喜欢这样。所有提交消息摘要都是空的，这很烦人。

因此，如果有一种很好的方法可以在克隆期间修复作者，也许还有一种方法可以修复提交消息？我只是想修剪 提交消息，以便 Github 正确读取它们。在 git-svn 的文档中找不到这样的东西，但也许我错过了一些东西。那么我该怎么做呢？

Answer 1

我创建了一个 Git 补丁来实现 git-svn 中的一个 --messages-prog 参数，它可以用来指定一个程序来在 pull 时过滤提交消息从 SVN 更改。对我很有用。我将补丁发送到 git 邮件列表，但没有得到任何反应。好吧，也许这个补丁对某人有用，所以我把它贴在这里:

From: Klaus Reimer <k@ailis.de>
Date: Sat, 26 May 2012 17:56:42 +0200
Subject: [PATCH] Implement --messages-prog parameter in git-svn

Some SVN repositories have strange policies for commit messages requiring an
empty line at the top of the commit message.  When you clone these
repositories with Git to mirror them on GitHub then no commit message
summaries are displayed at all at GitHub because they use the first line for
it (Which is empty).  You always have to open the commit message details
instead which is pretty annoying.  With the --messages-prog parameter you
can specify a program which can modify the SVN commit message before
committing it into the Git repo.  This works like the --authors-prog
parameter with the only difference that the commit message is piped into the
specified program instead of being passed to it as a command-line argument.

The same could be achieved by a "trim" feature but specifying a program
which can modify any aspect of a commit message is much more flexible.

Signed-off-by: Klaus Reimer <k@ailis.de>
---
 Documentation/git-svn.txt        |  5 +++++
 git-svn.perl                     | 26 +++++++++++++++++++++++++-
 t/t9147-git-svn-messages-prog.sh | 40 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 70 insertions(+), 1 deletion(-)
 create mode 100755 t/t9147-git-svn-messages-prog.sh

diff --git a/Documentation/git-svn.txt b/Documentation/git-svn.txt
index cfe8d2b..7289246 100644
--- a/Documentation/git-svn.txt
+++ b/Documentation/git-svn.txt
@@ -546,6 +546,11 @@ config key: svn.authorsfile
    expected to return a single line of the form "Name <email>",
    which will be treated as if included in the authors file.

+--messages-prog=<filename>::
+   If this option is specified, each SVN commit message is piped
+   through the given program. The output of this program is then
+   used as the new commit message instead.
+
 -q::
 --quiet::
    Make 'git svn' less verbose. Specify a second time to make it
diff --git a/git-svn.perl b/git-svn.perl
index c84842f..514c888 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -6,7 +6,7 @@ use warnings;
 use strict;
 use vars qw/   $AUTHOR $VERSION
        $sha1 $sha1_short $_revision $_repository
-       $_q $_authors $_authors_prog %users/;
+       $_q $_authors $_authors_prog $_messages_prog %users/;
 $AUTHOR = 'Eric Wong <normalperson@yhbt.net>';
 $VERSION = '@@GIT_VERSION@@';

@@ -120,6 +120,7 @@ my %remote_opts = ( 'username=s' => \$Git::SVN::Prompt::_username,
 my %fc_opts = ( 'follow-parent|follow!' => \$Git::SVN::_follow_parent,
        'authors-file|A=s' => \$_authors,
        'authors-prog=s' => \$_authors_prog,
+       'messages-prog=s' => \$_messages_prog,
        'repack:i' => \$Git::SVN::_repack,
        'noMetadata' => \$Git::SVN::_no_metadata,
        'useSvmProps' => \$Git::SVN::_use_svm_props,
@@ -359,6 +360,9 @@ load_authors() if $_authors;
 if (defined $_authors_prog) {
    $_authors_prog = "'" . File::Spec->rel2abs($_authors_prog) . "'";
 }
+if (defined $_messages_prog) {
+   $_messages_prog = "'" . File::Spec->rel2abs($_messages_prog) . "'";
+}

 unless ($cmd =~ /^(?:clone|init|multi-init|commit-diff)$/) {
    Git::SVN::Migration::migration_check();
@@ -2051,6 +2055,7 @@ use vars qw/$default_repo_id $default_ref_id $_no_metadata $_follow_parent
 use Carp qw/croak/;
 use File::Path qw/mkpath/;
 use File::Copy qw/copy/;
+use IPC::Open2;
 use IPC::Open3;
 use Time::Local;
 use Memoize;  # core since 5.8.0, Jul 2002
@@ -3409,6 +3414,22 @@ sub other_gs {
    $gs
 }

+sub call_messages_prog {
+   my ($orig_message) = @_;
+   my ($pid, $in, $out);
+   
+   $pid = open2($in, $out, $::_messages_prog)  
+       or die "$::_messages_prog failed with exit code $?\n";
+   print $out $orig_message;
+   close($out);
+   my ($message) = "";
+   while (<$in>) {
+       $message .= $_;
+   }
+   close($in);
+   return $message;    
+}
+
 sub call_authors_prog {
    my ($orig_author) = @_;
    $orig_author = command_oneline('rev-parse', '--sq-quote', $orig_author);
@@ -3809,6 +3830,9 @@ sub make_log_entry {

    $log_entry{date} = parse_svn_date($log_entry{date});
    $log_entry{log} .= "\n";
+   if (defined $::_messages_prog) {
+       $log_entry{log} = call_messages_prog($log_entry{log});
+   }
    my $author = $log_entry{author} = check_author($log_entry{author});
    my ($name, $email) = defined $::users{$author} ? @{$::users{$author}}
                               : ($author, undef);
diff --git a/t/t9147-git-svn-messages-prog.sh b/t/t9147-git-svn-messages-prog.sh
new file mode 100755
index 0000000..ebb42b0
--- /dev/null
+++ b/t/t9147-git-svn-messages-prog.sh
@@ -0,0 +1,40 @@
+#!/bin/sh
+
+test_description='git svn messages prog tests'
+
+. ./lib-git-svn.sh
+
+cat > svn-messages-prog <<'EOF'
+#!/bin/sh
+sed s/foo/bar/g
+EOF
+chmod +x svn-messages-prog
+
+test_expect_success 'setup svnrepo' '
+   svn mkdir -m "Unchanged message" "$svnrepo"/a
+   svn mkdir -m "Changed message: foo" "$svnrepo"/b
+   '
+
+test_expect_success 'import messages with prog' '
+   git svn clone --messages-prog=./svn-messages-prog \
+       "$svnrepo" x
+   '
+
+test_expect_success 'imported 2 revisions successfully' '
+   (
+       cd x
+       test "`git rev-list refs/remotes/git-svn | wc -l`" -eq 2
+   )
+   '
+
+test_expect_success 'messages-prog ran correctly' '
+   (
+       cd x
+       git rev-list -1 --pretty=raw refs/remotes/git-svn~1 | \
+         grep "^    Unchanged message" &&
+       git rev-list -1 --pretty=raw refs/remotes/git-svn~0 | \
+         grep "^    Changed message: bar"
+   )
+   '
+
+test_done
-- 1.7.10.2.605.gbefc5ed.dirty