Use first commit title for multi-commit PRs and fix auto-focus title field (#36606)

Fixes: https://github.com/go-gitea/gitea/issues/34865

1. When opening a PR from a branch with multiple commits, use the first
(oldest) commit's title as the default title instead of the branch name
2. Fix autofocus on PR title input field

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

routers/web/repo/compare.go

@@ -7,7 +7,6 @@ import (
 	gocontext "context"
 	"encoding/csv"
 	"errors"
-	"fmt"
 	"io"
 	"net/http"
 	"net/url"
@@ -426,6 +425,36 @@ func ParseCompareInfo(ctx *context.Context) *git_service.CompareInfo {
 	return compareInfo
 }
 
+func prepareNewPullRequestTitleContent(ci *git_service.CompareInfo, commits []*git_model.SignCommitWithStatuses) (title, content string) {
+	title = ci.HeadRef.ShortName()
+
+	if len(commits) > 0 {
+		// the "commits" are from "ShowPrettyFormatLogToList", which is ordered from newest to oldest, here take the oldest one
+		c := commits[len(commits)-1]
+		title = strings.TrimSpace(c.UserCommit.Summary())
+	}
+
+	if len(commits) == 1 {
+		// FIXME: GIT-COMMIT-MESSAGE-ENCODING: try to convert the encoding for commit message explicitly, ideally it should be done by a git commit struct method
+		c := commits[0]
+		_, content, _ = strings.Cut(strings.TrimSpace(c.UserCommit.CommitMessage), "\n")
+		content = strings.TrimSpace(content)
+		content = string(charset.ToUTF8([]byte(content), charset.ConvertOpts{}))
+	}
+
+	var titleTrailer string
+	// TODO: 255 doesn't seem to be a good limit for title, just keep the old behavior
+	title, titleTrailer = util.EllipsisDisplayStringX(title, 255)
+	if titleTrailer != "" {
+		if content != "" {
+			content = titleTrailer + "\n\n" + content
+		} else {
+			content = titleTrailer + "\n"
+		}
+	}
+	return title, content
+}
+
 // PrepareCompareDiff renders compare diff page
 func PrepareCompareDiff(
 	ctx *context.Context,
@@ -539,30 +568,7 @@ func PrepareCompareDiff(
 	ctx.Data["Commits"] = commits
 	ctx.Data["CommitCount"] = len(commits)
 
-	title := ci.HeadRef.ShortName()
-	if len(commits) == 1 {
-		c := commits[0]
-		title = strings.TrimSpace(c.UserCommit.Summary())
-
-		body := strings.Split(strings.TrimSpace(c.UserCommit.Message()), "\n")
-		if len(body) > 1 {
-			ctx.Data["content"] = strings.Join(body[1:], "\n")
-		}
-	}
-
-	if len(title) > 255 {
-		var trailer string
-		title, trailer = util.EllipsisDisplayStringX(title, 255)
-		if len(trailer) > 0 {
-			if ctx.Data["content"] != nil {
-				ctx.Data["content"] = fmt.Sprintf("%s\n\n%s", trailer, ctx.Data["content"])
-			} else {
-				ctx.Data["content"] = trailer + "\n"
-			}
-		}
-	}
-
-	ctx.Data["title"] = title
+	ctx.Data["title"], ctx.Data["content"] = prepareNewPullRequestTitleContent(ci, commits)
 	ctx.Data["Username"] = ci.HeadRepo.OwnerName
 	ctx.Data["Reponame"] = ci.HeadRepo.Name
 

routers/web/repo/compare_test.go

@@ -4,9 +4,16 @@
 package repo
 
 import (
+	"strings"
 	"testing"
+	"unicode/utf8"
 
+	asymkey_model "code.gitea.io/gitea/models/asymkey"
+	git_model "code.gitea.io/gitea/models/git"
 	issues_model "code.gitea.io/gitea/models/issues"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/git"
+	git_service "code.gitea.io/gitea/services/git"
 	"code.gitea.io/gitea/services/gitdiff"
 
 	"github.com/stretchr/testify/assert"
@@ -38,3 +45,47 @@ func TestAttachCommentsToLines(t *testing.T) {
 	assert.Equal(t, int64(300), section.Lines[1].Comments[0].ID)
 	assert.Equal(t, int64(301), section.Lines[1].Comments[1].ID)
 }
+
+func TestNewPullRequestTitleContent(t *testing.T) {
+	ci := &git_service.CompareInfo{HeadRef: "refs/heads/head-branch"}
+
+	mockCommit := func(msg string) *git_model.SignCommitWithStatuses {
+		return &git_model.SignCommitWithStatuses{
+			SignCommit: &asymkey_model.SignCommit{
+				UserCommit: &user_model.UserCommit{
+					Commit: &git.Commit{
+						CommitMessage: msg,
+					},
+				},
+			},
+		}
+	}
+
+	title, content := prepareNewPullRequestTitleContent(ci, nil)
+	assert.Equal(t, "head-branch", title)
+	assert.Empty(t, content)
+
+	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{mockCommit("title-only")})
+	assert.Equal(t, "title-only", title)
+	assert.Empty(t, content)
+
+	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{mockCommit("title-" + strings.Repeat("a", 255))})
+	assert.Equal(t, "title-aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa…", title)
+	assert.Equal(t, "…aaaaaaaaa\n", content)
+
+	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{mockCommit("title\nbody")})
+	assert.Equal(t, "title", title)
+	assert.Equal(t, "body", content)
+
+	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{mockCommit("a\xf0\xf0\xf0\nb\xf0\xf0\xf0")})
+	assert.Equal(t, "a?", title) // FIXME: GIT-COMMIT-MESSAGE-ENCODING: "title" doesn't use the same charset converting logic as "content"
+	assert.Equal(t, "b"+string(utf8.RuneError)+string(utf8.RuneError), content)
+
+	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{
+		// ordered from newest to oldest
+		mockCommit("title2\nbody2"),
+		mockCommit("title1\nbody1"),
+	})
+	assert.Equal(t, "title1", title)
+	assert.Empty(t, content)
+}