Merge branch 'fix/parsing-typechange-diff' into 'master'

Parse a typechange diff correctly

Closes #205

See merge request !136

4 files changed, 81 insertions, 1 deletions

diff --git a/internal/diff/diff.go b/internal/diff/diff.go
index 3c60e2d4f..8dd2e80f1 100644
--- a/internal/diff/diff.go
+++ b/internal/diff/diff.go
@@ -11,6 +11,8 @@ import (
 	"gitlab.com/gitlab-org/gitaly/internal/helper"
 )
 
+const blankID = "0000000000000000000000000000000000000000"
+
 // Diff represents a single parsed diff entry
 type Diff struct {
 	FromID    string
@@ -20,6 +22,7 @@ type Diff struct {
 	FromPath  []byte
 	ToPath    []byte
 	Binary    bool
+	Status    byte
 	RawChunks [][]byte
 }
 
@@ -172,6 +175,9 @@ func (parser *Parser) initializeCurrentDiff() error {
 		parser.err = err
 		return err
 	}
+	if parser.currentDiff.Status == 'T' {
+		parser.handleTypeChangeDiff()
+	}
 
 	return nil
 }
@@ -200,6 +206,25 @@ func (parser *Parser) findNextPatchFromPath() error {
 	return parser.err
 }
 
+func (parser *Parser) handleTypeChangeDiff() {
+	// GitLab wants to display the type change in the current diff as a removal followed by an addition.
+	// To make this happen we add a new raw line, which will become the addition on the next iteration of the parser.
+	// We change the current diff in-place so that it becomes a deletion.
+	newRawLine := fmt.Sprintf(
+		":%o %o %s %s A\t%s\n",
+		0,
+		parser.currentDiff.NewMode,
+		blankID,
+		parser.currentDiff.ToID,
+		parser.currentDiff.FromPath,
+	)
+
+	parser.currentDiff.NewMode = 0
+	parser.currentDiff.ToID = blankID
+
+	parser.rawLines = append([][]byte{[]byte(newRawLine)}, parser.rawLines...)
+}
+
 func parseRawLine(line []byte, diff *Diff) error {
 	matches := rawLineRegexp.FindSubmatch(line)
 	if len(matches) == 0 {
@@ -220,9 +245,10 @@ func parseRawLine(line []byte, diff *Diff) error {
 
 	diff.FromID = string(matches[3])
 	diff.ToID = string(matches[4])
+	diff.Status = matches[5][0]
 
 	diff.FromPath = unescape(helper.UnquoteBytes(matches[6]))
-	if matches[5][0] == 'C' || matches[5][0] == 'R' {
+	if diff.Status == 'C' || diff.Status == 'R' {
 		diff.ToPath = unescape(helper.UnquoteBytes(matches[7]))
 	} else {
 		diff.ToPath = diff.FromPath
diff --git a/internal/service/diff/commit_test.go b/internal/service/diff/commit_test.go
index 9b68a6723..bc1c36922 100644
--- a/internal/service/diff/commit_test.go
+++ b/internal/service/diff/commit_test.go
@@ -266,6 +266,55 @@ func TestSuccessfulCommitDiffRequestWithPaths(t *testing.T) {
 	assertExactReceivedDiffs(t, c, expectedDiffs)
 }
 
+func TestSuccessfulCommitDiffRequestWithTypeChangeDiff(t *testing.T) {
+	server := runDiffServer(t)
+	defer server.Stop()
+
+	client := newDiffClient(t)
+	repo := &pb.Repository{Path: testRepoPath}
+	rightCommit := "184a47d38677e2e439964859b877ae9bc424ab11"
+	leftCommit := "80d56eb72ba5d77fd8af857eced17a7d0640cb82"
+	rpcRequest := &pb.CommitDiffRequest{
+		Repository:    repo,
+		RightCommitId: rightCommit,
+		LeftCommitId:  leftCommit,
+	}
+
+	c, err := client.CommitDiff(context.Background(), rpcRequest)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expectedDiffs := []expectedDiff{
+		{
+			Diff: diff.Diff{
+				FromID:   "349cd0f6b1aba8538861d95783cbce6d49d747f8",
+				ToID:     "0000000000000000000000000000000000000000",
+				OldMode:  0120000,
+				NewMode:  0,
+				FromPath: []byte("gitaly/symlink-to-be-regular"),
+				ToPath:   []byte("gitaly/symlink-to-be-regular"),
+				Binary:   false,
+			},
+			ChunksCombined: testhelper.MustReadFile(t, "testdata/symlink-to-be-regular-deleted-chunks.txt"),
+		},
+		{
+			Diff: diff.Diff{
+				FromID:   "0000000000000000000000000000000000000000",
+				ToID:     "f9e5cc857610185e6feeb494a26bf27551a4f02b",
+				OldMode:  0,
+				NewMode:  0100644,
+				FromPath: []byte("gitaly/symlink-to-be-regular"),
+				ToPath:   []byte("gitaly/symlink-to-be-regular"),
+				Binary:   false,
+			},
+			ChunksCombined: testhelper.MustReadFile(t, "testdata/symlink-to-be-regular-added-chunks.txt"),
+		},
+	}
+
+	assertExactReceivedDiffs(t, c, expectedDiffs)
+}
+
 func TestSuccessfulCommitDiffRequestWithIgnoreWhitespaceChange(t *testing.T) {
 	server := runDiffServer(t)
 	defer server.Stop()
diff --git a/internal/service/diff/testdata/symlink-to-be-regular-added-chunks.txt b/internal/service/diff/testdata/symlink-to-be-regular-added-chunks.txt
new file mode 100644
index 000000000..5d0743717
--- /dev/null
+++ b/internal/service/diff/testdata/symlink-to-be-regular-added-chunks.txt
@@ -0,0 +1,2 @@
+@@ -0,0 +1 @@
++This was symlink, not anymore
diff --git a/internal/service/diff/testdata/symlink-to-be-regular-deleted-chunks.txt b/internal/service/diff/testdata/symlink-to-be-regular-deleted-chunks.txt
new file mode 100644
index 000000000..0037104bb
--- /dev/null
+++ b/internal/service/diff/testdata/symlink-to-be-regular-deleted-chunks.txt
@@ -0,0 +1,3 @@
+@@ -1 +0,0 @@
+-renamed-file
+\ No newline at end of file