Pull Request Pusher should be the author of the merge

services/pull/check.go

@@ -362,7 +362,17 @@ func manuallyMerged(ctx context.Context, pr *issues_model.PullRequest) bool {
 		return false
 	}
 
-	merger, _ := user_model.GetUserByEmail(ctx, commit.Author.Email)
+	var merger *user_model.User
+	if branch, err := git_model.GetBranch(ctx, pr.BaseRepoID, pr.BaseBranch); err == nil {
+		if err := branch.LoadPusher(ctx); err != nil {
+			log.Error("LoadPusher[%d:%s]: %v", pr.BaseRepoID, pr.BaseBranch, err)
+		}
+		merger = branch.Pusher
+	}
+
+	if merger == nil {
+		merger, _ = user_model.GetUserByEmail(ctx, commit.Author.Email)
+	}
 
 	// When the commit author is unknown set the BaseRepo owner as merger
 	if merger == nil {

tests/integration/manual_merge_test.go

@@ -0,0 +1,77 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"fmt"
+	"net/url"
+	"testing"
+	"time"
+
+	auth_model "code.gitea.io/gitea/models/auth"
+	issues_model "code.gitea.io/gitea/models/issues"
+	"code.gitea.io/gitea/models/unittest"
+	user_model "code.gitea.io/gitea/models/user"
+	api "code.gitea.io/gitea/modules/structs"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestManualMergeAutodetect(t *testing.T) {
+	onGiteaRun(t, func(t *testing.T, giteaURL *url.URL) {
+		// user2 is the repo owner
+		// user1 is the pusher/merger
+		user1 := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 1})
+		user2 := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
+		session2 := loginUser(t, user2.Name)
+
+		// Create a repo owned by user2
+		repoName := "manual-merge-autodetect"
+		var repo api.Repository
+		user2Ctx := NewAPITestContext(t, user2.Name, repoName, auth_model.AccessTokenScopeWriteRepository, auth_model.AccessTokenScopeWriteUser)
+		doAPICreateRepository(user2Ctx, false, func(t *testing.T, r api.Repository) {
+			repo = r
+		})(t)
+
+		// Enable autodetect manual merge
+		TrueValue := true
+		doAPIEditRepository(user2Ctx, &api.EditRepoOption{
+			HasPullRequests:       &TrueValue,
+			AllowManualMerge:      &TrueValue,
+			AutodetectManualMerge: &TrueValue,
+		})(t)
+
+		// Create a PR from a branch
+		branchName := "feature"
+		testEditFileToNewBranch(t, session2, user2.Name, repo.Name, repo.DefaultBranch, branchName, "README.md", "Manual Merge Test")
+
+		apiPull, err := doAPICreatePullRequest(NewAPITestContext(t, user1.Name, repo.Name, auth_model.AccessTokenScopeWriteRepository), user2.Name, repo.Name, repo.DefaultBranch, branchName)(t)
+		assert.NoError(t, err)
+
+		// user1 clones and pushes the branch to master (fast-forward)
+		dstPath := t.TempDir()
+		u, _ := url.Parse(giteaURL.String())
+		u.Path = fmt.Sprintf("%s/%s.git", user2.Name, repo.Name)
+		u.User = url.UserPassword(user1.Name, userPassword)
+
+		doGitClone(dstPath, u)(t)
+		doGitMerge(dstPath, "origin/"+branchName)(t)
+		doGitPushTestRepository(dstPath, "origin", repo.DefaultBranch)(t)
+
+		// Wait for the PR to be marked as merged by the background task
+		var pr *issues_model.PullRequest
+		require.Eventually(t, func() bool {
+			pr = unittest.AssertExistsAndLoadBean(t, &issues_model.PullRequest{ID: apiPull.ID})
+			return pr.HasMerged
+		}, 10*time.Second, 100*time.Millisecond)
+
+		// Check if the PR is merged and who is the merger
+		pr = unittest.AssertExistsAndLoadBean(t, &issues_model.PullRequest{ID: apiPull.ID})
+		assert.True(t, pr.HasMerged)
+		assert.Equal(t, issues_model.PullRequestStatusManuallyMerged, pr.Status)
+		// Merger should be user1 (the pusher), not the commit author (user2) or repo owner (user2)
+		assert.Equal(t, user1.ID, pr.MergerID)
+	})
+}