git-svn: check_cherry_pick should exclude commits already in our history

The merge-base between @$parents and $merge_tip may have been reached
through a merge commit.  This means that some commits that are ancestors
of @$parents will not be ancestors of $merge_base.  The mergeinfo
property will not list commits that are ancestors of @$parents, so we
need to explicitly exclude them.

[ew: squashed and cleaned up test case from Steven]

Signed-off-by: Steven Walter <stevenrwalter@gmail.com>
Acked-by: Eric Wong <normalperson@yhbt.net>

git-svn.perl

@@ -3118,9 +3118,10 @@ sub _rev_list {
 sub check_cherry_pick {
 	my $base = shift;
 	my $tip = shift;
+	my $parents = shift;
 	my @ranges = @_;
 	my %commits = map { $_ => 1 }
-		_rev_list("--no-merges", $tip, "--not", $base);
+		_rev_list("--no-merges", $tip, "--not", $base, @$parents);
 	for my $range ( @ranges ) {
 		delete @commits{_rev_list($range)};
 	}
@@ -3296,6 +3297,7 @@ sub find_extra_svn_parents {
 		# double check that there are no missing non-merge commits
 		my (@incomplete) = check_cherry_pick(
 			$merge_base, $merge_tip,
+			$parents,
 			@$ranges,
 		       );
 

t/t9157-git-svn-fetch-merge.sh

@@ -0,0 +1,50 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Steven Walter
+#
+
+test_description='git svn merge detection'
+. ./lib-git-svn.sh
+
+test_expect_success 'initialize source svn repo' '
+	svn_cmd mkdir -m x "$svnrepo"/trunk &&
+	svn_cmd mkdir -m x "$svnrepo"/branches &&
+	svn_cmd co "$svnrepo"/trunk "$SVN_TREE" &&
+	(
+		cd "$SVN_TREE" &&
+		touch foo &&
+		svn add foo &&
+		svn commit -m "initial commit" &&
+		svn cp -m branch "$svnrepo"/trunk "$svnrepo"/branches/branch1 &&
+		touch bar &&
+		svn add bar &&
+		svn commit -m x &&
+		svn cp -m branch "$svnrepo"/trunk "$svnrepo"/branches/branch2 &&
+		svn switch "$svnrepo"/branches/branch1 &&
+		touch baz &&
+		svn add baz &&
+		svn commit -m x &&
+		svn switch "$svnrepo"/trunk &&
+		svn merge "$svnrepo"/branches/branch1 &&
+		svn commit -m "merge" &&
+		svn switch "$svnrepo"/branches/branch1 &&
+		svn commit -m x &&
+		svn switch "$svnrepo"/branches/branch2 &&
+		svn merge "$svnrepo"/branches/branch1 &&
+		svn commit -m "merge branch1" &&
+		svn switch "$svnrepo"/trunk &&
+		svn merge "$svnrepo"/branches/branch2 &&
+		svn resolved baz &&
+		svn commit -m "merge branch2"
+	) &&
+	rm -rf "$SVN_TREE"
+'
+
+test_expect_success 'clone svn repo' '
+	git svn init -s "$svnrepo" &&
+	git svn fetch
+'
+
+test_expect_success 'verify merge commit' 'git rev-parse HEAD^2'
+
+test_done