fix

Author: wxiaoguang

services/pull/merge_squash.go

@@ -6,6 +6,7 @@ package pull
 import (
 	"fmt"
 	"strings"
+	"unicode"
 
 	repo_model "code.gitea.io/gitea/models/repo"
 	user_model "code.gitea.io/gitea/models/user"
@@ -51,6 +52,34 @@ func getAuthorSignatureSquash(ctx *mergeContext) (*git.Signature, error) {
 	return ctx.pr.Issue.Poster.NewGitSig(), nil
 }
 
+func AddCommitMessageTailer(message, tailerKey, tailerValue string) string {
+	tailerLine := tailerKey + ": " + tailerValue
+	if strings.Contains(message, "\n"+tailerLine+"\n") || strings.HasSuffix(message, "\n"+tailerLine) {
+		return message
+	}
+
+	if !strings.HasSuffix(message, "\n") {
+		message += "\n"
+	}
+	pos1 := strings.LastIndexByte(message[:len(message)-1], '\n')
+	pos2 := -1
+	if pos1 != -1 {
+		pos2 = strings.IndexByte(message[pos1:], ':')
+		if pos2 != -1 {
+			pos2 += pos1
+		}
+	}
+	var lastLine string
+	if pos1 != -1 && pos2 != -1 {
+		lastLine = message[pos1+1 : pos2+1]
+	}
+	lastLineIsTailerLine := lastLine != "" && unicode.IsUpper(rune(lastLine[0])) && strings.Contains(lastLine, "-")
+	if !strings.HasSuffix(message, "\n\n") && !lastLineIsTailerLine {
+		message += "\n"
+	}
+	return message + tailerLine
+}
+
 // doMergeStyleSquash squashes the tracking branch on the current HEAD (=base)
 func doMergeStyleSquash(ctx *mergeContext, message string) error {
 	sig, err := getAuthorSignatureSquash(ctx)
@@ -66,13 +95,8 @@ func doMergeStyleSquash(ctx *mergeContext, message string) error {
 
 	if setting.Repository.PullRequest.AddCoCommitterTrailers && ctx.committer.String() != sig.String() {
 		// add trailer
-		if !strings.HasSuffix(message, "\n") {
-			message += "\n"
-		}
-		if !strings.Contains(message, "Co-authored-by: "+sig.String()) {
-			message += "\nCo-authored-by: " + sig.String()
-		}
-		message += fmt.Sprintf("\nCo-committed-by: %s\n", sig.String())
+		message = AddCommitMessageTailer(message, "Co-authored-by", sig.String())
+		message = AddCommitMessageTailer(message, "Co-committed-by", sig.String()) // FIXME: this one should be removed, it is not really used or widely used
 	}
 	cmdCommit := git.NewCommand("commit").
 		AddOptionFormat("--author='%s <%s>'", sig.Name, sig.Email).

services/pull/merge_test.go

@@ -65,3 +65,15 @@ func Test_expandDefaultMergeMessage(t *testing.T) {
 		})
 	}
 }
+
+func TestAddCommitMessageTailer(t *testing.T) {
+	assert.Equal(t, "\n\nTest-tailer: TestValue", AddCommitMessageTailer("", "Test-tailer", "TestValue"))
+	assert.Equal(t, "title\n\nTest-tailer: TestValue", AddCommitMessageTailer("title", "Test-tailer", "TestValue"))
+	assert.Equal(t, "title\n\nTest-tailer: TestValue", AddCommitMessageTailer("title\n", "Test-tailer", "TestValue"))
+	assert.Equal(t, "title\n\nTest-tailer: TestValue", AddCommitMessageTailer("title\n\n", "Test-tailer", "TestValue"))
+	assert.Equal(t, "title\n\nTest-tailer: TestValue", AddCommitMessageTailer("title\n\nTest-tailer: TestValue", "Test-tailer", "TestValue"))
+	assert.Equal(t, "title\n\nTest-tailer: TestValue\n", AddCommitMessageTailer("title\n\nTest-tailer: TestValue\n", "Test-tailer", "TestValue"))
+
+	assert.Equal(t, "title\n\nTest-tailer: v1\nTest-tailer: v2", AddCommitMessageTailer("title\n\nTest-tailer: v1", "Test-tailer", "v2"))
+	assert.Equal(t, "title\n\nTest-tailer: v1\nTest-tailer: v2", AddCommitMessageTailer("title\n\nTest-tailer: v1\n", "Test-tailer", "v2"))
+}