[PATCH 3/3] git-svn: Correctly handle root commits in mergeinfo ranges

[Michael Haggerty <mhagger@alum.mit.edu>]

If the bottom of a mergeinfo range is a commit that maps to a git root
commit, then it doesn't have a parent.  In such a case, use git commit
range "$top_commit" rather than "$bottom_commit^..$top_commit".

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 git-svn.perl                           |    7 +++++--
 t/t9159-git-svn-no-parent-mergeinfo.sh |    2 +-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/git-svn.perl b/git-svn.perl
index 2cc9242..7e121ae 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -3111,8 +3111,11 @@ sub lookup_svn_merge {
 			next;
 		}
 
-		push @merged_commit_ranges,
-			"$bottom_commit^..$top_commit";
+		if (scalar(command('rev-parse', "$bottom_commit^@"))) {
+			push @merged_commit_ranges, "$bottom_commit^..$top_commit";
+		} else {
+			push @merged_commit_ranges, "$top_commit";
+		}
 
 		if ( !defined $tip or $top > $tip ) {
 			$tip = $top;
diff --git a/t/t9159-git-svn-no-parent-mergeinfo.sh b/t/t9159-git-svn-no-parent-mergeinfo.sh
index 9472de3..85120b7 100755
--- a/t/t9159-git-svn-no-parent-mergeinfo.sh
+++ b/t/t9159-git-svn-no-parent-mergeinfo.sh
@@ -2,7 +2,7 @@
 test_description='git svn handling of root commits in merge ranges'
 . ./lib-git-svn.sh
 
-test_expect_failure 'test handling of root commits in merge ranges' '
+test_expect_success 'test handling of root commits in merge ranges' '
 	mkdir -p init/trunk init/branches init/tags &&
 	echo "r1" > init/trunk/file.txt &&
 	svn_cmd import -m "initial import" init "$svnrepo" &&
-- 
1.7.5.4