[GITEA] GetScheduledMergeByPullID may involve a system user

Refs: https://codeberg.org/forgejo/forgejo/issues/1897
(cherry picked from commit ddc3c22558)
(cherry picked from commit a7fe969b93)
(cherry picked from commit 62bda95774)
(cherry picked from commit 8149a822c7)
(cherry picked from commit 9ed4e685eb)

models/pull/automerge.go

@@ -74,7 +74,7 @@ func GetScheduledMergeByPullID(ctx context.Context, pullID int64) (bool, *AutoMe
 		return false, nil, err
 	}
 
-	doer, err := user_model.GetUserByID(ctx, scheduledPRM.DoerID)
+	doer, err := user_model.GetPossibleUserByID(ctx, scheduledPRM.DoerID)
 	if err != nil {
 		return false, nil, err
 	}

tests/integration/forgejo_git_test.go

@@ -0,0 +1,139 @@
+// Copyright Earl Warren <contact@earl-warren.org>
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"net/http"
+	"net/url"
+	"os"
+	"path"
+	"testing"
+	"time"
+
+	actions_model "code.gitea.io/gitea/models/actions"
+	auth_model "code.gitea.io/gitea/models/auth"
+	"code.gitea.io/gitea/models/db"
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/models/unittest"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/git"
+	api "code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/tests"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestActionsUserGit(t *testing.T) {
+	onGiteaRun(t, testActionsUserGit)
+}
+
+func NewActionsUserTestContext(t *testing.T, username, reponame string) APITestContext {
+	t.Helper()
+
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{Name: reponame})
+	repoOwner := unittest.AssertExistsAndLoadBean(t, &user_model.User{Name: username})
+
+	task := unittest.AssertExistsAndLoadBean(t, &actions_model.ActionTask{ID: 47})
+	task.RepoID = repo.ID
+	task.OwnerID = repoOwner.ID
+	task.GenerateToken()
+
+	actions_model.UpdateTask(db.DefaultContext, task)
+	return APITestContext{
+		Session:  emptyTestSession(t),
+		Token:    task.Token,
+		Username: username,
+		Reponame: reponame,
+	}
+}
+
+func testActionsUserGit(t *testing.T, u *url.URL) {
+	username := "user2"
+	reponame := "repo1"
+	httpContext := NewAPITestContext(t, username, reponame, auth_model.AccessTokenScopeWriteRepository, auth_model.AccessTokenScopeWriteUser)
+
+	for _, testCase := range []struct {
+		name string
+		head string
+		ctx  APITestContext
+	}{
+		{
+			name: "UserTypeIndividual",
+			head: "individualhead",
+			ctx:  httpContext,
+		},
+		{
+			name: "ActionsUser",
+			head: "actionsuserhead",
+			ctx:  NewActionsUserTestContext(t, username, reponame),
+		},
+	} {
+		t.Run("CreatePR "+testCase.name, func(t *testing.T) {
+			defer tests.PrintCurrentTest(t)()
+
+			dstPath := t.TempDir()
+			u.Path = httpContext.GitPath()
+			u.User = url.UserPassword(httpContext.Username, userPassword)
+			t.Run("Clone", doGitClone(dstPath, u))
+			t.Run("PopulateBranch", doActionsUserPopulateBranch(dstPath, &httpContext, "master", testCase.head))
+			t.Run("CreatePR", doActionsUserPR(httpContext, testCase.ctx, "master", testCase.head))
+		})
+	}
+}
+
+func doActionsUserPopulateBranch(dstPath string, ctx *APITestContext, baseBranch, headBranch string) func(t *testing.T) {
+	return func(t *testing.T) {
+		defer tests.PrintCurrentTest(t)()
+
+		t.Run("CreateHeadBranch", doGitCreateBranch(dstPath, headBranch))
+
+		t.Run("AddCommit", func(t *testing.T) {
+			err := os.WriteFile(path.Join(dstPath, "test_file"), []byte("## test content"), 0o666)
+			if !assert.NoError(t, err) {
+				return
+			}
+
+			err = git.AddChanges(dstPath, true)
+			assert.NoError(t, err)
+
+			err = git.CommitChanges(dstPath, git.CommitChangesOptions{
+				Committer: &git.Signature{
+					Email: "user2@example.com",
+					Name:  "user2",
+					When:  time.Now(),
+				},
+				Author: &git.Signature{
+					Email: "user2@example.com",
+					Name:  "user2",
+					When:  time.Now(),
+				},
+				Message: "Testing commit 1",
+			})
+			assert.NoError(t, err)
+		})
+
+		t.Run("Push", func(t *testing.T) {
+			err := git.NewCommand(git.DefaultContext, "push", "origin").AddDynamicArguments("HEAD:refs/heads/" + headBranch).Run(&git.RunOpts{Dir: dstPath})
+			assert.NoError(t, err)
+		})
+	}
+}
+
+func doActionsUserPR(ctx, doerCtx APITestContext, baseBranch, headBranch string) func(t *testing.T) {
+	return func(t *testing.T) {
+		defer tests.PrintCurrentTest(t)()
+		var pr api.PullRequest
+		var err error
+
+		// Create a test pullrequest
+		t.Run("CreatePullRequest", func(t *testing.T) {
+			pr, err = doAPICreatePullRequest(doerCtx, ctx.Username, ctx.Reponame, baseBranch, headBranch)(t)
+			assert.NoError(t, err)
+		})
+		doerCtx.ExpectedCode = http.StatusCreated
+		t.Run("AutoMergePR", doAPIAutoMergePullRequest(doerCtx, ctx.Username, ctx.Reponame, pr.Index))
+		// Ensure the PR page works
+		t.Run("EnsureCanSeePull", doEnsureCanSeePull(ctx, pr))
+	}
+}