[PATCH v2] git svn : hook before 'git svn dcommit'

["Frédéric Heitzmann" <frederic.heitzmann@gmail.com>]

The 'pre-svn-dcommit' hook is called before 'git svn dcommit', which aborts
if return value is not zero. The only parameter given to the hook is the
reference given to 'git svn dcommit'. If no paramter was used, hook gets HEAD
as its only parameter.

Signed-off-by: Frédéric Heitzmann <frederic.heitzmann@gmail.com>
---
There was no remark about patch v2.
I suppose it should be OK for merging upstream.

 Documentation/git-svn.txt |   14 +++++++++++++-
 git-svn.perl              |   21 +++++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletions(-)

diff --git a/Documentation/git-svn.txt b/Documentation/git-svn.txt
index 713e523..ec87ed3 100644
--- a/Documentation/git-svn.txt
+++ b/Documentation/git-svn.txt
@@ -700,6 +700,18 @@ section because they affect the 'git-svn-id:' metadata line, except
 for rewriteRoot and rewriteUUID which can be used together.
 
 
+HOOKS
+-----
+
+The 'pre-svn-dcommit' hook is called by 'git svn dcommit' and can be used to
+prevent some diff to be committed to a SVN repository. It may typically be
+used to filter some intermediate patches, which were committed into git but
+must not find their way to the SVN repository.
+
+It takes a single parameter, the reference given to 'git svn dcommit'. If the
+hook exists with a non zero-status, 'git svn dcommit' will abort.
+
+
 BASIC EXAMPLES
 --------------
 
@@ -901,7 +913,7 @@ reset) branches-maxRev and/or tags-maxRev as appropriate.
 
 SEE ALSO
 --------
-linkgit:git-rebase[1]
+linkgit:git-rebase[1], linkgit:githooks[5]
 
 GIT
 ---
diff --git a/git-svn.perl b/git-svn.perl
index 89f83fd..a537858 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -396,6 +396,25 @@ sub init_subdir {
 	$_repository = Git->repository(Repository => $ENV{GIT_DIR});
 }
 
+sub pre_svn_dcommit_hook {
+	my $head = shift;
+
+	my $hook = "$ENV{GIT_DIR}/hooks/pre-svn-dcommit";
+	return 0 if ! -e $hook || ! -x $hook;
+
+	system($hook, $head);
+	if ($? == -1) {
+		print "[pre_svn_dcommit_hook] failed to execute $hook: $!\n";
+		return 1;
+	} elsif ($? & 127) {
+		printf "[pre_svn_dcommit_hook] child died with signal %d, %s coredump\n",
+		($? & 127),  ($? & 128) ? 'with' : 'without';
+		return 1;
+	} else {
+		return $? >> 8;
+	}
+}
+
 sub cmd_clone {
 	my ($url, $path) = @_;
 	if (!defined $path &&
@@ -505,6 +524,8 @@ sub cmd_dcommit {
 		. "or stash them with `git stash'.\n";
 	$head ||= 'HEAD';
 
+	return if pre_svn_dcommit_hook($head);
+
 	my $old_head;
 	if ($head ne 'HEAD') {
 		$old_head = eval {
-- 
1.7.6.133.gd3b55a