Merge branch 'jc-check-for-first-commit' into 'master'

Use empty tree if initial commit

See merge request gitlab-org/gitaly!1075

3 files changed, 21 insertions, 1 deletions

diff --git a/changelogs/unreleased/jc-check-for-first-commit.yml b/changelogs/unreleased/jc-check-for-first-commit.yml
new file mode 100644
index 000000000..60595e912
--- /dev/null
+++ b/changelogs/unreleased/jc-check-for-first-commit.yml
@@ -0,0 +1,5 @@
+---
+title: Use empty tree if initial commit
+merge_request: 1075
+author:
+type: fixed
diff --git a/internal/service/commit/stats.go b/internal/service/commit/stats.go
index c9b32b171..724b7c05d 100644
--- a/internal/service/commit/stats.go
+++ b/internal/service/commit/stats.go
@@ -35,7 +35,15 @@ func commitStats(ctx context.Context, in *gitalypb.CommitStatsRequest) (*gitalyp
 		return nil, fmt.Errorf("commit not found: %q", in.Revision)
 	}
 
-	cmd, err := git.Command(ctx, in.Repository, "diff", "--numstat", commit.Id+"^", commit.Id)
+	args := []string{"diff", "--numstat"}
+
+	if len(commit.GetParentIds()) == 0 {
+		args = append(args, git.EmptyTreeID, commit.Id)
+	} else {
+		args = append(args, commit.Id+"^", commit.Id)
+	}
+
+	cmd, err := git.Command(ctx, in.Repository, args...)
 	if err != nil {
 		return nil, err
 	}
diff --git a/internal/service/commit/stats_test.go b/internal/service/commit/stats_test.go
index 53af68217..f39534730 100644
--- a/internal/service/commit/stats_test.go
+++ b/internal/service/commit/stats_test.go
@@ -58,6 +58,13 @@ func TestCommitStatsSuccess(t *testing.T) {
 			additions: 0,
 			deletions: 0,
 		},
+		{
+			desc:      "initial commit",
+			revision:  "1a0b36b3",
+			oid:       "1a0b36b3cdad1d2ee32457c102a8c0b7056fa863",
+			additions: 43,
+			deletions: 0,
+		},
 	}
 
 	for _, tc := range tests {