format/packfile: fix bug when the delta depth is equals to 50

2 files changed, 10 insertions, 0 deletions

diff --git a/plumbing/format/packfile/delta_selector.go b/plumbing/format/packfile/delta_selector.go
index a73a209..20c8cea 100644
--- a/plumbing/format/packfile/delta_selector.go
+++ b/plumbing/format/packfile/delta_selector.go
@@ -142,6 +142,11 @@ func (dw *deltaSelector) deltaSizeLimit(targetSize int64, baseDepth int,
 	d := int64(targetDepth)
 	n := targetSize
 
+	// If target depth is bigger than maxDepth, this delta is not suitable to be used.
+	if d >= maxDepth {
+		return 0
+	}
+
 	// If src is whole (depth=0) and base is near limit (depth=9/10)
 	// any delta using src can be 10x larger and still be better.
 	//
diff --git a/plumbing/format/packfile/delta_selector_test.go b/plumbing/format/packfile/delta_selector_test.go
index 9a8833f..cbbbc89 100644
--- a/plumbing/format/packfile/delta_selector_test.go
+++ b/plumbing/format/packfile/delta_selector_test.go
@@ -197,3 +197,8 @@ func (s *DeltaSelectorSuite) TestObjectsToPack(c *C) {
 	c.Assert(otp[2].IsDelta(), Equals, true)
 	c.Assert(otp[2].Depth, Equals, 2)
 }
+
+func (s *DeltaSelectorSuite) TestMaxDepth(c *C) {
+	dsl := s.ds.deltaSizeLimit(0, 0, int(maxDepth), true)
+	c.Assert(dsl, Equals, int64(0))
+}