Merge pull request #27 from chrisd8088/merge-name-only-keys

use filenames only as keys when merging tree entries

Author: chrisd8088

tree.go

@@ -115,22 +115,18 @@ func (t *Tree) Encode(to io.Writer) (n int, err error) {
 func (t *Tree) Merge(others ...*TreeEntry) *Tree {
 	unseen := make(map[string]*TreeEntry)
 
-	// Build a cache of name+filemode to *TreeEntry.
+	// Build a cache of name to *TreeEntry.
 	for _, other := range others {
-		key := fmt.Sprintf("%s\x00%o", other.Name, other.Filemode)
-
-		unseen[key] = other
+		unseen[other.Name] = other
 	}
 
 	// Map the existing entries ("t.Entries") into a new set by either
 	// copying an existing entry, or replacing it with a new one.
 	entries := make([]*TreeEntry, 0, len(t.Entries))
 	for _, entry := range t.Entries {
-		key := fmt.Sprintf("%s\x00%o", entry.Name, entry.Filemode)
-
-		if other, ok := unseen[key]; ok {
+		if other, ok := unseen[entry.Name]; ok {
 			entries = append(entries, other)
-			delete(unseen, key)
+			delete(unseen, entry.Name)
 		} else {
 			oid := make([]byte, len(entry.Oid))
 			copy(oid, entry.Oid)

tree_test.go

@@ -123,7 +123,7 @@ func TestTreeDecodingShaBoundary(t *testing.T) {
 func TestTreeMergeReplaceElements(t *testing.T) {
 	e1 := &TreeEntry{Name: "a", Filemode: 0100644, Oid: []byte{0x1}}
 	e2 := &TreeEntry{Name: "b", Filemode: 0100644, Oid: []byte{0x2}}
-	e3 := &TreeEntry{Name: "c", Filemode: 0100644, Oid: []byte{0x3}}
+	e3 := &TreeEntry{Name: "c", Filemode: 0100755, Oid: []byte{0x3}}
 
 	e4 := &TreeEntry{Name: "b", Filemode: 0100644, Oid: []byte{0x4}}
 	e5 := &TreeEntry{Name: "c", Filemode: 0100644, Oid: []byte{0x5}}
@@ -157,6 +157,7 @@ func TestMergeInsertElementsInSubtreeOrder(t *testing.T) {
 	assert.True(t, bytes.Equal(t1.Entries[1].Oid, []byte{0x2}))
 	assert.True(t, bytes.Equal(t1.Entries[2].Oid, []byte{0x3}))
 
+	require.Len(t, t2.Entries, 4)
 	assert.True(t, bytes.Equal(t2.Entries[0].Oid, []byte{0x4}))
 	assert.True(t, bytes.Equal(t2.Entries[1].Oid, []byte{0x1}))
 	assert.True(t, bytes.Equal(t2.Entries[2].Oid, []byte{0x2}))