Fix bug

Author: lunny

modules/git/repo_compare.go

@@ -246,18 +246,40 @@ func (repo *Repository) GetDiffOrPatch(base, head string, w io.Writer, patch, bi
 
 // GetDiff generates and returns patch data between given revisions, optimized for human readability
 func (repo *Repository) GetDiff(base, head string, w io.Writer) error {
-	return NewCommand(repo.Ctx, "diff", "-p").AddDynamicArguments(base, head).Run(&RunOpts{
-		Dir:    repo.Path,
-		Stdout: w,
-	})
+	stderr := new(bytes.Buffer)
+	err := NewCommand(repo.Ctx, "diff", "-p").AddDynamicArguments(base + "..." + head).
+		Run(&RunOpts{
+			Dir:    repo.Path,
+			Stdout: w,
+			Stderr: stderr,
+		})
+	if err != nil && bytes.Contains(stderr.Bytes(), []byte("no merge base")) {
+		return NewCommand(repo.Ctx, "diff", "-p").AddDynamicArguments(base, head).
+			Run(&RunOpts{
+				Dir:    repo.Path,
+				Stdout: w,
+			})
+	}
+	return err
 }
 
 // GetDiffBinary generates and returns patch data between given revisions, including binary diffs.
 func (repo *Repository) GetDiffBinary(base, head string, w io.Writer) error {
-	return NewCommand(repo.Ctx, "diff", "-p", "--binary", "--histogram").AddDynamicArguments(base, head).Run(&RunOpts{
-		Dir:    repo.Path,
-		Stdout: w,
-	})
+	stderr := new(bytes.Buffer)
+	err := NewCommand(repo.Ctx, "diff", "-p", "--binary", "--histogram").AddDynamicArguments(base + "..." + head).
+		Run(&RunOpts{
+			Dir:    repo.Path,
+			Stdout: w,
+			Stderr: stderr,
+		})
+	if err != nil && bytes.Contains(stderr.Bytes(), []byte("no merge base")) {
+		return NewCommand(repo.Ctx, "diff", "-p", "--binary", "--histogram").AddDynamicArguments(base, head).
+			Run(&RunOpts{
+				Dir:    repo.Path,
+				Stdout: w,
+			})
+	}
+	return err
 }
 
 // GetPatch generates and returns format-patch data between given revisions, able to be used with `git apply`

services/gitdiff/gitdiff.go

@@ -641,6 +641,7 @@ parsingLoop:
 				}
 			case strings.HasPrefix(line, "new file"):
 				curFile.Type = DiffFileAdd
+				curFile.OldName = ""
 				curFile.IsCreated = true
 				if strings.HasPrefix(line, "new file mode ") {
 					curFile.Mode = prepareValue(line, "new file mode ")
@@ -688,7 +689,7 @@ parsingLoop:
 						if line[len(line)-2] == '\t' {
 							curFile.Name = curFile.Name[:len(curFile.Name)-1]
 						}
-						if curFile.OldName == "" {
+						if curFile.OldName == "" && curFile.Type != DiffFileAdd {
 							curFile.OldName = curFile.Name
 						}
 					} else {

tests/integration/api_pull_test.go

@@ -51,7 +51,7 @@ func TestAPIViewPulls(t *testing.T) {
 	assert.Len(t, pull.RequestedReviewersTeams, 0)
 	assert.EqualValues(t, 5, pull.RequestedReviewers[0].ID)
 	assert.EqualValues(t, 6, pull.RequestedReviewers[1].ID)
-	assert.EqualValues(t, 2, pull.ChangedFiles)
+	assert.EqualValues(t, 1, pull.ChangedFiles)
 
 	if assert.EqualValues(t, 5, pull.ID) {
 		resp = ctx.Session.MakeRequest(t, NewRequest(t, "GET", pull.DiffURL), http.StatusOK)
@@ -97,7 +97,7 @@ func TestAPIViewPulls(t *testing.T) {
 		assert.NoError(t, err)
 		if assert.Len(t, patch.Files, pull.ChangedFiles) {
 			assert.Equal(t, "README.md", patch.Files[0].Name)
-			assert.Empty(t, patch.Files[0].OldName)
+			assert.NotEmpty(t, patch.Files[0].OldName)
 			assert.EqualValues(t, pull.Additions, patch.Files[0].Addition)
 			assert.EqualValues(t, pull.Deletions, patch.Files[0].Deletion)
 			assert.Equal(t, gitdiff.DiffFileChange, patch.Files[0].Type)