Use for a repo action one database transaction (#19576)

... more context

(part of #9307)

29 files changed, 270 insertions, 260 deletions

diff --git a/integrations/pull_merge_test.go b/integrations/pull_merge_test.go
index f8e8c79a88..476f7ab52f 100644
--- a/integrations/pull_merge_test.go
+++ b/integrations/pull_merge_test.go
@@ -243,11 +243,11 @@ func TestCantMergeConflict(t *testing.T) {
 		gitRepo, err := git.OpenRepository(git.DefaultContext, repo_model.RepoPath(user1.Name, repo1.Name))
 		assert.NoError(t, err)
 
-		err = pull.Merge(git.DefaultContext, pr, user1, gitRepo, repo_model.MergeStyleMerge, "", "CONFLICT")
+		err = pull.Merge(pr, user1, gitRepo, repo_model.MergeStyleMerge, "", "CONFLICT")
 		assert.Error(t, err, "Merge should return an error due to conflict")
 		assert.True(t, models.IsErrMergeConflicts(err), "Merge error is not a conflict error")
 
-		err = pull.Merge(git.DefaultContext, pr, user1, gitRepo, repo_model.MergeStyleRebase, "", "CONFLICT")
+		err = pull.Merge(pr, user1, gitRepo, repo_model.MergeStyleRebase, "", "CONFLICT")
 		assert.Error(t, err, "Merge should return an error due to conflict")
 		assert.True(t, models.IsErrRebaseConflicts(err), "Merge error is not a conflict error")
 		gitRepo.Close()
@@ -342,7 +342,7 @@ func TestCantMergeUnrelated(t *testing.T) {
 			BaseBranch: "base",
 		}).(*models.PullRequest)
 
-		err = pull.Merge(git.DefaultContext, pr, user1, gitRepo, repo_model.MergeStyleMerge, "", "UNRELATED")
+		err = pull.Merge(pr, user1, gitRepo, repo_model.MergeStyleMerge, "", "UNRELATED")
 		assert.Error(t, err, "Merge should return an error due to unrelated")
 		assert.True(t, models.IsErrMergeUnrelatedHistories(err), "Merge error is not a unrelated histories error")
 		gitRepo.Close()
diff --git a/models/branches.go b/models/branches.go
index f4ded8588f..47fd3dc0a4 100644
--- a/models/branches.go
+++ b/models/branches.go
@@ -104,7 +104,7 @@ func (protectBranch *ProtectedBranch) CanUserPush(userID int64) bool {
 }
 
 // IsUserMergeWhitelisted checks if some user is whitelisted to merge to this branch
-func IsUserMergeWhitelisted(protectBranch *ProtectedBranch, userID int64, permissionInRepo Permission) bool {
+func IsUserMergeWhitelisted(ctx context.Context, protectBranch *ProtectedBranch, userID int64, permissionInRepo Permission) bool {
 	if !protectBranch.EnableMergeWhitelist {
 		// Then we need to fall back on whether the user has write permission
 		return permissionInRepo.CanWrite(unit.TypeCode)
@@ -118,7 +118,7 @@ func IsUserMergeWhitelisted(protectBranch *ProtectedBranch, userID int64, permis
 		return false
 	}
 
-	in, err := organization.IsUserInTeams(db.DefaultContext, userID, protectBranch.MergeWhitelistTeamIDs)
+	in, err := organization.IsUserInTeams(ctx, userID, protectBranch.MergeWhitelistTeamIDs)
 	if err != nil {
 		log.Error("IsUserInTeams: %v", err)
 		return false
@@ -159,16 +159,16 @@ func isUserOfficialReviewer(ctx context.Context, protectBranch *ProtectedBranch,
 }
 
 // HasEnoughApprovals returns true if pr has enough granted approvals.
-func (protectBranch *ProtectedBranch) HasEnoughApprovals(pr *PullRequest) bool {
+func (protectBranch *ProtectedBranch) HasEnoughApprovals(ctx context.Context, pr *PullRequest) bool {
 	if protectBranch.RequiredApprovals == 0 {
 		return true
 	}
-	return protectBranch.GetGrantedApprovalsCount(pr) >= protectBranch.RequiredApprovals
+	return protectBranch.GetGrantedApprovalsCount(ctx, pr) >= protectBranch.RequiredApprovals
 }
 
 // GetGrantedApprovalsCount returns the number of granted approvals for pr. A granted approval must be authored by a user in an approval whitelist.
-func (protectBranch *ProtectedBranch) GetGrantedApprovalsCount(pr *PullRequest) int64 {
-	sess := db.GetEngine(db.DefaultContext).Where("issue_id = ?", pr.IssueID).
+func (protectBranch *ProtectedBranch) GetGrantedApprovalsCount(ctx context.Context, pr *PullRequest) int64 {
+	sess := db.GetEngine(ctx).Where("issue_id = ?", pr.IssueID).
 		And("type = ?", ReviewTypeApprove).
 		And("official = ?", true).
 		And("dismissed = ?", false)
@@ -185,11 +185,11 @@ func (protectBranch *ProtectedBranch) GetGrantedApprovalsCount(pr *PullRequest)
 }
 
 // MergeBlockedByRejectedReview returns true if merge is blocked by rejected reviews
-func (protectBranch *ProtectedBranch) MergeBlockedByRejectedReview(pr *PullRequest) bool {
+func (protectBranch *ProtectedBranch) MergeBlockedByRejectedReview(ctx context.Context, pr *PullRequest) bool {
 	if !protectBranch.BlockOnRejectedReviews {
 		return false
 	}
-	rejectExist, err := db.GetEngine(db.DefaultContext).Where("issue_id = ?", pr.IssueID).
+	rejectExist, err := db.GetEngine(ctx).Where("issue_id = ?", pr.IssueID).
 		And("type = ?", ReviewTypeReject).
 		And("official = ?", true).
 		And("dismissed = ?", false).
@@ -204,11 +204,11 @@ func (protectBranch *ProtectedBranch) MergeBlockedByRejectedReview(pr *PullReque
 
 // MergeBlockedByOfficialReviewRequests block merge because of some review request to official reviewer
 // of from official review
-func (protectBranch *ProtectedBranch) MergeBlockedByOfficialReviewRequests(pr *PullRequest) bool {
+func (protectBranch *ProtectedBranch) MergeBlockedByOfficialReviewRequests(ctx context.Context, pr *PullRequest) bool {
 	if !protectBranch.BlockOnOfficialReviewRequests {
 		return false
 	}
-	has, err := db.GetEngine(db.DefaultContext).Where("issue_id = ?", pr.IssueID).
+	has, err := db.GetEngine(ctx).Where("issue_id = ?", pr.IssueID).
 		And("type = ?", ReviewTypeRequest).
 		And("official = ?", true).
 		Exist(new(Review))
diff --git a/models/db/context.go b/models/db/context.go
index 1cd23d453c..c823952cf6 100644
--- a/models/db/context.go
+++ b/models/db/context.go
@@ -103,7 +103,14 @@ func WithContext(f func(ctx *Context) error) error {
 }
 
 // WithTx represents executing database operations on a transaction
-func WithTx(f func(ctx context.Context) error) error {
+// you can optionally change the context to a parrent one
+func WithTx(f func(ctx context.Context) error, stdCtx ...context.Context) error {
+	parentCtx := DefaultContext
+	if len(stdCtx) != 0 && stdCtx[0] != nil {
+		// TODO: make sure parent context has no open session
+		parentCtx = stdCtx[0]
+	}
+
 	sess := x.NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
@@ -111,7 +118,7 @@ func WithTx(f func(ctx context.Context) error) error {
 	}
 
 	if err := f(&Context{
-		Context: DefaultContext,
+		Context: parentCtx,
 		e:       sess,
 	}); err != nil {
 		return err
diff --git a/models/issue.go b/models/issue.go
index 2a41cbc28e..98e64adafd 100644
--- a/models/issue.go
+++ b/models/issue.go
@@ -591,7 +591,7 @@ func ReplaceIssueLabels(issue *Issue, labels []*Label, doer *user_model.User) (e
 }
 
 // ReadBy sets issue to be read by given user.
-func (issue *Issue) ReadBy(userID int64) error {
+func (issue *Issue) ReadBy(ctx context.Context, userID int64) error {
 	if err := UpdateIssueUserByRead(userID, issue.ID); err != nil {
 		return err
 	}
@@ -635,7 +635,7 @@ func doChangeIssueStatus(ctx context.Context, issue *Issue, doer *user_model.Use
 	// Check for open dependencies
 	if issue.IsClosed && issue.Repo.IsDependenciesEnabledCtx(ctx) {
 		// only check if dependencies are enabled and we're about to close an issue, otherwise reopening an issue would fail when there are unsatisfied dependencies
-		noDeps, err := issueNoDependenciesLeft(e, issue)
+		noDeps, err := IssueNoDependenciesLeft(ctx, issue)
 		if err != nil {
 			return nil, err
 		}
@@ -693,13 +693,7 @@ func doChangeIssueStatus(ctx context.Context, issue *Issue, doer *user_model.Use
 }
 
 // ChangeIssueStatus changes issue status to open or closed.
-func ChangeIssueStatus(issue *Issue, doer *user_model.User, isClosed bool) (*Comment, error) {
-	ctx, committer, err := db.TxContext()
-	if err != nil {
-		return nil, err
-	}
-	defer committer.Close()
-
+func ChangeIssueStatus(ctx context.Context, issue *Issue, doer *user_model.User, isClosed bool) (*Comment, error) {
 	if err := issue.LoadRepo(ctx); err != nil {
 		return nil, err
 	}
@@ -707,16 +701,7 @@ func ChangeIssueStatus(issue *Issue, doer *user_model.User, isClosed bool) (*Com
 		return nil, err
 	}
 
-	comment, err := changeIssueStatus(ctx, issue, doer, isClosed, false)
-	if err != nil {
-		return nil, err
-	}
-
-	if err = committer.Commit(); err != nil {
-		return nil, fmt.Errorf("Commit: %v", err)
-	}
-
-	return comment, nil
+	return changeIssueStatus(ctx, issue, doer, isClosed, false)
 }
 
 // ChangeIssueTitle changes the title of this issue, as the given user.
@@ -787,16 +772,11 @@ func ChangeIssueRef(issue *Issue, doer *user_model.User, oldRef string) (err err
 }
 
 // AddDeletePRBranchComment adds delete branch comment for pull request issue
-func AddDeletePRBranchComment(doer *user_model.User, repo *repo_model.Repository, issueID int64, branchName string) error {
-	issue, err := getIssueByID(db.GetEngine(db.DefaultContext), issueID)
-	if err != nil {
-		return err
-	}
-	ctx, committer, err := db.TxContext()
+func AddDeletePRBranchComment(ctx context.Context, doer *user_model.User, repo *repo_model.Repository, issueID int64, branchName string) error {
+	issue, err := getIssueByID(db.GetEngine(ctx), issueID)
 	if err != nil {
 		return err
 	}
-	defer committer.Close()
 	opts := &CreateCommentOptions{
 		Type:   CommentTypeDeleteBranch,
 		Doer:   doer,
@@ -804,11 +784,8 @@ func AddDeletePRBranchComment(doer *user_model.User, repo *repo_model.Repository
 		Issue:  issue,
 		OldRef: branchName,
 	}
-	if _, err = CreateCommentCtx(ctx, opts); err != nil {
-		return err
-	}
-
-	return committer.Commit()
+	_, err = CreateCommentCtx(ctx, opts)
+	return err
 }
 
 // UpdateIssueAttachments update attachments by UUIDs for the issue
diff --git a/models/issue_comment.go b/models/issue_comment.go
index 39c2818eed..ceea878662 100644
--- a/models/issue_comment.go
+++ b/models/issue_comment.go
@@ -284,14 +284,15 @@ type PushActionContent struct {
 
 // LoadIssue loads issue from database
 func (c *Comment) LoadIssue() (err error) {
-	return c.loadIssue(db.GetEngine(db.DefaultContext))
+	return c.LoadIssueCtx(db.DefaultContext)
 }
 
-func (c *Comment) loadIssue(e db.Engine) (err error) {
+// LoadIssueCtx loads issue from database
+func (c *Comment) LoadIssueCtx(ctx context.Context) (err error) {
 	if c.Issue != nil {
 		return nil
 	}
-	c.Issue, err = getIssueByID(e, c.IssueID)
+	c.Issue, err = getIssueByID(db.GetEngine(ctx), c.IssueID)
 	return
 }
 
@@ -1126,7 +1127,7 @@ func UpdateComment(c *Comment, doer *user_model.User) error {
 	if _, err := sess.ID(c.ID).AllCols().Update(c); err != nil {
 		return err
 	}
-	if err := c.loadIssue(sess); err != nil {
+	if err := c.LoadIssueCtx(ctx); err != nil {
 		return err
 	}
 	if err := c.addCrossReferences(ctx, doer, true); err != nil {
diff --git a/models/issue_dependency.go b/models/issue_dependency.go
index d2c5785b90..b292db57e0 100644
--- a/models/issue_dependency.go
+++ b/models/issue_dependency.go
@@ -5,6 +5,8 @@
 package models
 
 import (
+	"context"
+
 	"code.gitea.io/gitea/models/db"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -117,12 +119,8 @@ func issueDepExists(e db.Engine, issueID, depID int64) (bool, error) {
 }
 
 // IssueNoDependenciesLeft checks if issue can be closed
-func IssueNoDependenciesLeft(issue *Issue) (bool, error) {
-	return issueNoDependenciesLeft(db.GetEngine(db.DefaultContext), issue)
-}
-
-func issueNoDependenciesLeft(e db.Engine, issue *Issue) (bool, error) {
-	exists, err := e.
+func IssueNoDependenciesLeft(ctx context.Context, issue *Issue) (bool, error) {
+	exists, err := db.GetEngine(ctx).
 		Table("issue_dependency").
 		Select("issue.*").
 		Join("INNER", "issue", "issue.id = issue_dependency.dependency_id").
diff --git a/models/issue_dependency_test.go b/models/issue_dependency_test.go
index 1789de5dc0..345a9077cd 100644
--- a/models/issue_dependency_test.go
+++ b/models/issue_dependency_test.go
@@ -7,6 +7,7 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/models/unittest"
 	user_model "code.gitea.io/gitea/models/user"
 
@@ -43,15 +44,15 @@ func TestCreateIssueDependency(t *testing.T) {
 	_ = unittest.AssertExistsAndLoadBean(t, &Comment{Type: CommentTypeAddDependency, PosterID: user1.ID, IssueID: issue1.ID})
 
 	// Check if dependencies left is correct
-	left, err := IssueNoDependenciesLeft(issue1)
+	left, err := IssueNoDependenciesLeft(db.DefaultContext, issue1)
 	assert.NoError(t, err)
 	assert.False(t, left)
 
 	// Close #2 and check again
-	_, err = ChangeIssueStatus(issue2, user1, true)
+	_, err = ChangeIssueStatus(db.DefaultContext, issue2, user1, true)
 	assert.NoError(t, err)
 
-	left, err = IssueNoDependenciesLeft(issue1)
+	left, err = IssueNoDependenciesLeft(db.DefaultContext, issue1)
 	assert.NoError(t, err)
 	assert.True(t, left)
 
diff --git a/models/issue_test.go b/models/issue_test.go
index 5382c04f43..9b82fc80fb 100644
--- a/models/issue_test.go
+++ b/models/issue_test.go
@@ -443,12 +443,12 @@ func TestIssue_DeleteIssue(t *testing.T) {
 	assert.NoError(t, err)
 	err = CreateIssueDependency(user, issue1, issue2)
 	assert.NoError(t, err)
-	left, err := IssueNoDependenciesLeft(issue1)
+	left, err := IssueNoDependenciesLeft(db.DefaultContext, issue1)
 	assert.NoError(t, err)
 	assert.False(t, left)
 	err = DeleteIssue(&Issue{ID: 2})
 	assert.NoError(t, err)
-	left, err = IssueNoDependenciesLeft(issue1)
+	left, err = IssueNoDependenciesLeft(db.DefaultContext, issue1)
 	assert.NoError(t, err)
 	assert.True(t, left)
 }
diff --git a/models/issue_xref.go b/models/issue_xref.go
index 2647f9c656..cd1c122252 100644
--- a/models/issue_xref.go
+++ b/models/issue_xref.go
@@ -249,7 +249,7 @@ func (comment *Comment) addCrossReferences(stdCtx context.Context, doer *user_mo
 	if comment.Type != CommentTypeCode && comment.Type != CommentTypeComment {
 		return nil
 	}
-	if err := comment.loadIssue(db.GetEngine(stdCtx)); err != nil {
+	if err := comment.LoadIssueCtx(stdCtx); err != nil {
 		return err
 	}
 	ctx := &crossReferencesContext{
@@ -340,9 +340,9 @@ func (comment *Comment) RefIssueIdent() string {
 //                                  \/     \/   |__|           \/     \/
 
 // ResolveCrossReferences will return the list of references to close/reopen by this PR
-func (pr *PullRequest) ResolveCrossReferences() ([]*Comment, error) {
+func (pr *PullRequest) ResolveCrossReferences(ctx context.Context) ([]*Comment, error) {
 	unfiltered := make([]*Comment, 0, 5)
-	if err := db.GetEngine(db.DefaultContext).
+	if err := db.GetEngine(ctx).
 		Where("ref_repo_id = ? AND ref_issue_id = ?", pr.Issue.RepoID, pr.Issue.ID).
 		In("ref_action", []references.XRefAction{references.XRefActionCloses, references.XRefActionReopens}).
 		OrderBy("id").
diff --git a/models/issue_xref_test.go b/models/issue_xref_test.go
index 1ae5fb360f..677caa48ba 100644
--- a/models/issue_xref_test.go
+++ b/models/issue_xref_test.go
@@ -98,7 +98,7 @@ func TestXRef_ResolveCrossReferences(t *testing.T) {
 	i1 := testCreateIssue(t, 1, 2, "title1", "content1", false)
 	i2 := testCreateIssue(t, 1, 2, "title2", "content2", false)
 	i3 := testCreateIssue(t, 1, 2, "title3", "content3", false)
-	_, err := ChangeIssueStatus(i3, d, true)
+	_, err := ChangeIssueStatus(db.DefaultContext, i3, d, true)
 	assert.NoError(t, err)
 
 	pr := testCreatePR(t, 1, 2, "titlepr", fmt.Sprintf("closes #%d", i1.Index))
@@ -118,7 +118,7 @@ func TestXRef_ResolveCrossReferences(t *testing.T) {
 	c4 := testCreateComment(t, 1, 2, pr.Issue.ID, fmt.Sprintf("closes #%d", i3.Index))
 	r4 := unittest.AssertExistsAndLoadBean(t, &Comment{IssueID: i3.ID, RefIssueID: pr.Issue.ID, RefCommentID: c4.ID}).(*Comment)
 
-	refs, err := pr.ResolveCrossReferences()
+	refs, err := pr.ResolveCrossReferences(db.DefaultContext)
 	assert.NoError(t, err)
 	assert.Len(t, refs, 3)
 	assert.Equal(t, rp.ID, refs[0].ID, "bad ref rp: %+v", refs[0])
diff --git a/models/pull.go b/models/pull.go
index 437b202d3f..d056888130 100644
--- a/models/pull.go
+++ b/models/pull.go
@@ -227,23 +227,23 @@ func (pr *PullRequest) LoadProtectedBranchCtx(ctx context.Context) (err error) {
 }
 
 // GetDefaultMergeMessage returns default message used when merging pull request
-func (pr *PullRequest) GetDefaultMergeMessage() (string, error) {
+func (pr *PullRequest) GetDefaultMergeMessage(ctx context.Context) (string, error) {
 	if pr.HeadRepo == nil {
 		var err error
-		pr.HeadRepo, err = repo_model.GetRepositoryByID(pr.HeadRepoID)
+		pr.HeadRepo, err = repo_model.GetRepositoryByIDCtx(ctx, pr.HeadRepoID)
 		if err != nil {
 			return "", fmt.Errorf("GetRepositoryById[%d]: %v", pr.HeadRepoID, err)
 		}
 	}
-	if err := pr.LoadIssue(); err != nil {
+	if err := pr.LoadIssueCtx(ctx); err != nil {
 		return "", fmt.Errorf("Cannot load issue %d for PR id %d: Error: %v", pr.IssueID, pr.ID, err)
 	}
-	if err := pr.LoadBaseRepo(); err != nil {
+	if err := pr.LoadBaseRepoCtx(ctx); err != nil {
 		return "", fmt.Errorf("LoadBaseRepo: %v", err)
 	}
 
 	issueReference := "#"
-	if pr.BaseRepo.UnitEnabled(unit.TypeExternalTracker) {
+	if pr.BaseRepo.UnitEnabledCtx(ctx, unit.TypeExternalTracker) {
 		issueReference = "!"
 	}
 
@@ -337,14 +337,14 @@ func (pr *PullRequest) getReviewedByLines(writer io.Writer) error {
 }
 
 // GetDefaultSquashMessage returns default message used when squash and merging pull request
-func (pr *PullRequest) GetDefaultSquashMessage() (string, error) {
-	if err := pr.LoadIssue(); err != nil {
+func (pr *PullRequest) GetDefaultSquashMessage(ctx context.Context) (string, error) {
+	if err := pr.LoadIssueCtx(ctx); err != nil {
 		return "", fmt.Errorf("LoadIssue: %v", err)
 	}
-	if err := pr.LoadBaseRepo(); err != nil {
+	if err := pr.LoadBaseRepoCtx(ctx); err != nil {
 		return "", fmt.Errorf("LoadBaseRepo: %v", err)
 	}
-	if pr.BaseRepo.UnitEnabled(unit.TypeExternalTracker) {
+	if pr.BaseRepo.UnitEnabledCtx(ctx, unit.TypeExternalTracker) {
 		return fmt.Sprintf("%s (!%d)", pr.Issue.Title, pr.Issue.Index), nil
 	}
 	return fmt.Sprintf("%s (#%d)", pr.Issue.Title, pr.Issue.Index), nil
@@ -371,7 +371,7 @@ func (pr *PullRequest) IsEmpty() bool {
 }
 
 // SetMerged sets a pull request to merged and closes the corresponding issue
-func (pr *PullRequest) SetMerged() (bool, error) {
+func (pr *PullRequest) SetMerged(ctx context.Context) (bool, error) {
 	if pr.HasMerged {
 		return false, fmt.Errorf("PullRequest[%d] already merged", pr.Index)
 	}
@@ -380,12 +380,6 @@ func (pr *PullRequest) SetMerged() (bool, error) {
 	}
 
 	pr.HasMerged = true
-
-	ctx, committer, err := db.TxContext()
-	if err != nil {
-		return false, err
-	}
-	defer committer.Close()
 	sess := db.GetEngine(ctx)
 
 	if _, err := sess.Exec("UPDATE `issue` SET `repo_id` = `repo_id` WHERE `id` = ?", pr.IssueID); err != nil {
@@ -432,9 +426,6 @@ func (pr *PullRequest) SetMerged() (bool, error) {
 		return false, fmt.Errorf("Failed to update pr[%d]: %v", pr.ID, err)
 	}
 
-	if err := committer.Commit(); err != nil {
-		return false, fmt.Errorf("Commit: %v", err)
-	}
 	return true, nil
 }
 
diff --git a/models/pull_list.go b/models/pull_list.go
index 055119a1e5..ca09e28a93 100644
--- a/models/pull_list.go
+++ b/models/pull_list.go
@@ -62,8 +62,8 @@ func GetUnmergedPullRequestsByHeadInfo(repoID int64, branch string) ([]*PullRequ
 
 // HasUnmergedPullRequestsByHeadInfo checks if there are open and not merged pull request
 // by given head information (repo and branch)
-func HasUnmergedPullRequestsByHeadInfo(repoID int64, branch string) (bool, error) {
-	return db.GetEngine(db.DefaultContext).
+func HasUnmergedPullRequestsByHeadInfo(ctx context.Context, repoID int64, branch string) (bool, error) {
+	return db.GetEngine(ctx).
 		Where("head_repo_id = ? AND head_branch = ? AND has_merged = ? AND issue.is_closed = ? AND flow = ?",
 			repoID, branch, false, false, PullRequestFlowGithub).
 		Join("INNER", "issue", "issue.id = pull_request.issue_id").
diff --git a/models/pull_test.go b/models/pull_test.go
index 6194ac0e24..92cf9a6524 100644
--- a/models/pull_test.go
+++ b/models/pull_test.go
@@ -110,11 +110,11 @@ func TestGetUnmergedPullRequest(t *testing.T) {
 func TestHasUnmergedPullRequestsByHeadInfo(t *testing.T) {
 	assert.NoError(t, unittest.PrepareTestDatabase())
 
-	exist, err := HasUnmergedPullRequestsByHeadInfo(1, "branch2")
+	exist, err := HasUnmergedPullRequestsByHeadInfo(db.DefaultContext, 1, "branch2")
 	assert.NoError(t, err)
 	assert.Equal(t, true, exist)
 
-	exist, err = HasUnmergedPullRequestsByHeadInfo(1, "not_exist_branch")
+	exist, err = HasUnmergedPullRequestsByHeadInfo(db.DefaultContext, 1, "not_exist_branch")
 	assert.NoError(t, err)
 	assert.Equal(t, false, exist)
 }
@@ -261,13 +261,13 @@ func TestPullRequest_GetDefaultMergeMessage_InternalTracker(t *testing.T) {
 	assert.NoError(t, unittest.PrepareTestDatabase())
 	pr := unittest.AssertExistsAndLoadBean(t, &PullRequest{ID: 2}).(*PullRequest)
 
-	msg, err := pr.GetDefaultMergeMessage()
+	msg, err := pr.GetDefaultMergeMessage(db.DefaultContext)
 	assert.NoError(t, err)
 	assert.Equal(t, "Merge pull request 'issue3' (#3) from branch2 into master", msg)
 
 	pr.BaseRepoID = 1
 	pr.HeadRepoID = 2
-	msg, err = pr.GetDefaultMergeMessage()
+	msg, err = pr.GetDefaultMergeMessage(db.DefaultContext)
 	assert.NoError(t, err)
 	assert.Equal(t, "Merge pull request 'issue3' (#3) from user2/repo1:branch2 into master", msg)
 }
@@ -287,13 +287,22 @@ func TestPullRequest_GetDefaultMergeMessage_ExternalTracker(t *testing.T) {
 
 	pr := unittest.AssertExistsAndLoadBean(t, &PullRequest{ID: 2, BaseRepo: baseRepo}).(*PullRequest)
 
-	msg, err := pr.GetDefaultMergeMessage()
+	msg, err := pr.GetDefaultMergeMessage(db.DefaultContext)
 	assert.NoError(t, err)
 	assert.Equal(t, "Merge pull request 'issue3' (!3) from branch2 into master", msg)
 
 	pr.BaseRepoID = 1
 	pr.HeadRepoID = 2
-	msg, err = pr.GetDefaultMergeMessage()
+	msg, err = pr.GetDefaultMergeMessage(db.DefaultContext)
 	assert.NoError(t, err)
 	assert.Equal(t, "Merge pull request 'issue3' (!3) from user2/repo1:branch2 into master", msg)
 }
+
+func TestPullRequest_GetDefaultSquashMessage(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+	pr := unittest.AssertExistsAndLoadBean(t, &PullRequest{ID: 2}).(*PullRequest)
+
+	msg, err := pr.GetDefaultSquashMessage(db.DefaultContext)
+	assert.NoError(t, err)
+	assert.Equal(t, "issue3 (#3)", msg)
+}
diff --git a/models/repo.go b/models/repo.go
index 9c2fce8d3c..e934b24fb3 100644
--- a/models/repo.go
+++ b/models/repo.go
@@ -455,8 +455,8 @@ func CreateRepository(ctx context.Context, doer, u *user_model.User, repo *repo_
 			}
 		}
 
-		if isAdmin, err := isUserRepoAdmin(ctx, repo, doer); err != nil {
-			return fmt.Errorf("isUserRepoAdmin: %v", err)
+		if isAdmin, err := IsUserRepoAdminCtx(ctx, repo, doer); err != nil {
+			return fmt.Errorf("IsUserRepoAdminCtx: %v", err)
 		} else if !isAdmin {
 			// Make creator repo admin if it wasn't assigned automatically
 			if err = addCollaborator(ctx, repo, doer); err != nil {
@@ -1215,7 +1215,7 @@ func DeleteDeployKey(ctx context.Context, doer *user_model.User, id int64) error
 		if err != nil {
 			return fmt.Errorf("GetRepositoryByID: %v", err)
 		}
-		has, err := isUserRepoAdmin(ctx, repo, doer)
+		has, err := IsUserRepoAdminCtx(ctx, repo, doer)
 		if err != nil {
 			return fmt.Errorf("GetUserRepoPermission: %v", err)
 		} else if !has {
diff --git a/models/repo/repo.go b/models/repo/repo.go
index fc72d36dac..8af6357bf3 100644
--- a/models/repo/repo.go
+++ b/models/repo/repo.go
@@ -302,8 +302,19 @@ func (repo *Repository) LoadUnits(ctx context.Context) (err error) {
 }
 
 // UnitEnabled if this repository has the given unit enabled
-func (repo *Repository) UnitEnabled(tp unit.Type) bool {
-	if err := repo.LoadUnits(db.DefaultContext); err != nil {
+func (repo *Repository) UnitEnabled(tp unit.Type) (result bool) {
+	if err := db.WithContext(func(ctx *db.Context) error {
+		result = repo.UnitEnabledCtx(ctx, tp)
+		return nil
+	}); err != nil {
+		log.Error("repo.UnitEnabled: %v", err)
+	}
+	return
+}
+
+// UnitEnabled if this repository has the given unit enabled
+func (repo *Repository) UnitEnabledCtx(ctx context.Context, tp unit.Type) bool {
+	if err := repo.LoadUnits(ctx); err != nil {
 		log.Warn("Error loading repository (ID: %d) units: %s", repo.ID, err.Error())
 	}
 	for _, unit := range repo.Units {
diff --git a/models/repo_permission.go b/models/repo_permission.go
index bc31b873f2..8ba6b86145 100644
--- a/models/repo_permission.go
+++ b/models/repo_permission.go
@@ -331,10 +331,11 @@ func IsUserRealRepoAdmin(repo *repo_model.Repository, user *user_model.User) (bo
 
 // IsUserRepoAdmin return true if user has admin right of a repo
 func IsUserRepoAdmin(repo *repo_model.Repository, user *user_model.User) (bool, error) {
-	return isUserRepoAdmin(db.DefaultContext, repo, user)
+	return IsUserRepoAdminCtx(db.DefaultContext, repo, user)
 }
 
-func isUserRepoAdmin(ctx context.Context, repo *repo_model.Repository, user *user_model.User) (bool, error) {
+// IsUserRepoAdminCtx return true if user has admin right of a repo
+func IsUserRepoAdminCtx(ctx context.Context, repo *repo_model.Repository, user *user_model.User) (bool, error) {
 	if user == nil || repo == nil {
 		return false, nil
 	}
diff --git a/modules/convert/convert.go b/modules/convert/convert.go
index bd06f4dbf4..3a12ed8f1f 100644
--- a/modules/convert/convert.go
+++ b/modules/convert/convert.go
@@ -87,7 +87,7 @@ func ToBranch(repo *repo_model.Repository, b *git.Branch, c *git.Commit, bp *mod
 			return nil, err
 		}
 		branch.UserCanPush = bp.CanUserPush(user.ID)
-		branch.UserCanMerge = models.IsUserMergeWhitelisted(bp, user.ID, permission)
+		branch.UserCanMerge = models.IsUserMergeWhitelisted(db.DefaultContext, bp, user.ID, permission)
 	}
 
 	return branch, nil
diff --git a/modules/git/commit_test.go b/modules/git/commit_test.go
index aac7de5d46..fb8c22dfd3 100644
--- a/modules/git/commit_test.go
+++ b/modules/git/commit_test.go
@@ -67,6 +67,7 @@ empty commit`
 	gitRepo, err := openRepositoryWithDefaultContext(filepath.Join(testReposDir, "repo1_bare"))
 	assert.NoError(t, err)
 	assert.NotNil(t, gitRepo)
+	defer gitRepo.Close()
 
 	commitFromReader, err := CommitFromReader(gitRepo, sha, strings.NewReader(commitString))
 	assert.NoError(t, err)
@@ -111,6 +112,7 @@ func TestHasPreviousCommit(t *testing.T) {
 
 	repo, err := openRepositoryWithDefaultContext(bareRepo1Path)
 	assert.NoError(t, err)
+	defer repo.Close()
 
 	commit, err := repo.GetCommit("8006ff9adbf0cb94da7dad9e537e53817f9fa5c0")
 	assert.NoError(t, err)
diff --git a/routers/api/v1/repo/pull.go b/routers/api/v1/repo/pull.go
index 9517802183..d6f349e332 100644
--- a/routers/api/v1/repo/pull.go
+++ b/routers/api/v1/repo/pull.go
@@ -726,7 +726,8 @@ func MergePullRequest(ctx *context.APIContext) {
 	//     "$ref": "#/responses/error"
 
 	form := web.GetForm(ctx).(*forms.MergePullRequestForm)
-	pr, err := models.GetPullRequestByIndex(ctx.Repo.Repository.ID, ctx.ParamsInt64(":index"))
+
+	pr, err := models.GetPullRequestByIndexCtx(ctx, ctx.Repo.Repository.ID, ctx.ParamsInt64(":index"))
 	if err != nil {
 		if models.IsErrPullRequestNotExist(err) {
 			ctx.NotFound("GetPullRequestByIndex", err)
@@ -741,7 +742,7 @@ func MergePullRequest(ctx *context.APIContext) {
 		return
 	}
 
-	if err := pr.LoadIssue(); err != nil {
+	if err := pr.LoadIssueCtx(ctx); err != nil {
 		ctx.Error(http.StatusInternalServerError, "LoadIssue", err)
 		return
 	}
@@ -749,7 +750,7 @@ func MergePullRequest(ctx *context.APIContext) {
 
 	if ctx.IsSigned {
 		// Update issue-user.
-		if err = pr.Issue.ReadBy(ctx.Doer.ID); err != nil {
+		if err = pr.Issue.ReadBy(ctx, ctx.Doer.ID); err != nil {
 			ctx.Error(http.StatusInternalServerError, "ReadBy", err)
 			return
 		}
@@ -758,6 +759,7 @@ func MergePullRequest(ctx *context.APIContext) {
 	manuallMerge := repo_model.MergeStyle(form.Do) == repo_model.MergeStyleManuallyMerged
 	force := form.ForceMerge != nil && *form.ForceMerge
 
+	// start with merging by checking
 	if err := pull_service.CheckPullMergable(ctx, ctx.Doer, &ctx.Repo.Permission, pr, manuallMerge, force); err != nil {
 		if errors.Is(err, pull_service.ErrIsClosed) {
 			ctx.NotFound()
@@ -798,15 +800,14 @@ func MergePullRequest(ctx *context.APIContext) {
 	}
 
 	// set defaults to propagate needed fields
-	if err := form.SetDefaults(pr); err != nil {
+	if err := form.SetDefaults(ctx, pr); err != nil {
 		ctx.ServerError("SetDefaults", fmt.Errorf("SetDefaults: %v", err))
 		return
 	}
 
-	if err := pull_service.Merge(ctx, pr, ctx.Doer, ctx.Repo.GitRepo, repo_model.MergeStyle(form.Do), form.HeadCommitID, form.MergeTitleField); err != nil {
+	if err := pull_service.Merge(pr, ctx.Doer, ctx.Repo.GitRepo, repo_model.MergeStyle(form.Do), form.HeadCommitID, form.MergeTitleField); err != nil {
 		if models.IsErrInvalidMergeStyle(err) {
 			ctx.Error(http.StatusMethodNotAllowed, "Invalid merge style", fmt.Errorf("%s is not allowed an allowed merge style for this repository", repo_model.MergeStyle(form.Do)))
-			return
 		} else if models.IsErrMergeConflicts(err) {
 			conflictError := err.(models.ErrMergeConflicts)
 			ctx.JSON(http.StatusConflict, conflictError)
@@ -818,28 +819,25 @@ func MergePullRequest(ctx *context.APIContext) {
 			ctx.JSON(http.StatusConflict, conflictError)
 		} else if git.IsErrPushOutOfDate(err) {
 			ctx.Error(http.StatusConflict, "Merge", "merge push out of date")
-			return
 		} else if models.IsErrSHADoesNotMatch(err) {
 			ctx.Error(http.StatusConflict, "Merge", "head out of date")
-			return
 		} else if git.IsErrPushRejected(err) {
 			errPushRej := err.(*git.ErrPushRejected)
 			if len(errPushRej.Message) == 0 {
 				ctx.Error(http.StatusConflict, "Merge", "PushRejected without remote error message")
-				return
+			} else {
+				ctx.Error(http.StatusConflict, "Merge", "PushRejected with remote message: "+errPushRej.Message)
 			}
-			ctx.Error(http.StatusConflict, "Merge", "PushRejected with remote message: "+errPushRej.Message)
-			return
+		} else {
+			ctx.Error(http.StatusInternalServerError, "Merge", err)
 		}
-		ctx.Error(http.StatusInternalServerError, "Merge", err)
 		return
 	}
-
 	log.Trace("Pull request merged: %d", pr.ID)
 
 	if form.DeleteBranchAfterMerge {
 		// Don't cleanup when there are other PR's that use this branch as head branch.
-		exist, err := models.HasUnmergedPullRequestsByHeadInfo(pr.HeadRepoID, pr.HeadBranch)
+		exist, err := models.HasUnmergedPullRequestsByHeadInfo(ctx, pr.HeadRepoID, pr.HeadBranch)
 		if err != nil {
 			ctx.ServerError("HasUnmergedPullRequestsByHeadInfo", err)
 			return
@@ -873,7 +871,7 @@ func MergePullRequest(ctx *context.APIContext) {
 			}
 			return
 		}
-		if err := models.AddDeletePRBranchComment(ctx.Doer, pr.BaseRepo, pr.Issue.ID, pr.HeadBranch); err != nil {
+		if err := models.AddDeletePRBranchComment(ctx, ctx.Doer, pr.BaseRepo, pr.Issue.ID, pr.HeadBranch); err != nil {
 			// Do not fail here as branch has already been deleted
 			log.Error("DeleteBranch: %v", err)
 		}
diff --git a/routers/private/hook_pre_receive.go b/routers/private/hook_pre_receive.go
index 731b36fc1e..d2203a1f99 100644
--- a/routers/private/hook_pre_receive.go
+++ b/routers/private/hook_pre_receive.go
@@ -311,7 +311,7 @@ func preReceiveBranch(ctx *preReceiveContext, oldCommitID, newCommitID, refFullN
 
 		// Now check if the user is allowed to merge PRs for this repository
 		// Note: we can use ctx.perm and ctx.user directly as they will have been loaded above
-		allowedMerge, err := pull_service.IsUserAllowedToMerge(pr, ctx.userPerm, ctx.user)
+		allowedMerge, err := pull_service.IsUserAllowedToMerge(ctx, pr, ctx.userPerm, ctx.user)
 		if err != nil {
 			log.Error("Error calculating if allowed to merge: %v", err)
 			ctx.JSON(http.StatusInternalServerError, private.Response{
diff --git a/routers/web/repo/issue.go b/routers/web/repo/issue.go
index a54ad3306b..cf919e0c32 100644
--- a/routers/web/repo/issue.go
+++ b/routers/web/repo/issue.go
@@ -1295,7 +1295,7 @@ func ViewIssue(ctx *context.Context) {
 
 	if ctx.IsSigned {
 		// Update issue-user.
-		if err = issue.ReadBy(ctx.Doer.ID); err != nil {
+		if err = issue.ReadBy(ctx, ctx.Doer.ID); err != nil {
 			ctx.ServerError("ReadBy", err)
 			return
 		}
@@ -1557,7 +1557,7 @@ func ViewIssue(ctx *context.Context) {
 				ctx.ServerError("GetUserRepoPermission", err)
 				return
 			}
-			ctx.Data["AllowMerge"], err = pull_service.IsUserAllowedToMerge(pull, perm, ctx.Doer)
+			ctx.Data["AllowMerge"], err = pull_service.IsUserAllowedToMerge(ctx, pull, perm, ctx.Doer)
 			if err != nil {
 				ctx.ServerError("IsUserAllowedToMerge", err)
 				return
@@ -1606,12 +1606,11 @@ func ViewIssue(ctx *context.Context) {
 			if ctx.Doer != nil {
 				showMergeInstructions = pull.ProtectedBranch.CanUserPush(ctx.Doer.ID)
 			}
-			cnt := pull.ProtectedBranch.GetGrantedApprovalsCount(pull)
-			ctx.Data["IsBlockedByApprovals"] = !pull.ProtectedBranch.HasEnoughApprovals(pull)
-			ctx.Data["IsBlockedByRejection"] = pull.ProtectedBranch.MergeBlockedByRejectedReview(pull)
-			ctx.Data["IsBlockedByOfficialReviewRequests"] = pull.ProtectedBranch.MergeBlockedByOfficialReviewRequests(pull)
+			ctx.Data["IsBlockedByApprovals"] = !pull.ProtectedBranch.HasEnoughApprovals(ctx, pull)
+			ctx.Data["IsBlockedByRejection"] = pull.ProtectedBranch.MergeBlockedByRejectedReview(ctx, pull)
+			ctx.Data["IsBlockedByOfficialReviewRequests"] = pull.ProtectedBranch.MergeBlockedByOfficialReviewRequests(ctx, pull)
 			ctx.Data["IsBlockedByOutdatedBranch"] = pull.ProtectedBranch.MergeBlockedByOutdatedBranch(pull)
-			ctx.Data["GrantedApprovals"] = cnt
+			ctx.Data["GrantedApprovals"] = pull.ProtectedBranch.GetGrantedApprovalsCount(ctx, pull)
 			ctx.Data["RequireSigned"] = pull.ProtectedBranch.RequireSignedCommits
 			ctx.Data["ChangedProtectedFiles"] = pull.ChangedProtectedFiles
 			ctx.Data["IsBlockedByChangedProtectedFiles"] = len(pull.ChangedProtectedFiles) != 0
@@ -1641,7 +1640,7 @@ func ViewIssue(ctx *context.Context) {
 			(!pull.HasMerged || ctx.Data["HeadBranchCommitID"] == ctx.Data["PullHeadCommitID"])
 
 		if isPullBranchDeletable && pull.HasMerged {
-			exist, err := models.HasUnmergedPullRequestsByHeadInfo(pull.HeadRepoID, pull.HeadBranch)
+			exist, err := models.HasUnmergedPullRequestsByHeadInfo(ctx, pull.HeadRepoID, pull.HeadBranch)
 			if err != nil {
 				ctx.ServerError("HasUnmergedPullRequestsByHeadInfo", err)
 				return
diff --git a/routers/web/repo/pull.go b/routers/web/repo/pull.go
index 99faa54138..6cda560f3c 100644
--- a/routers/web/repo/pull.go
+++ b/routers/web/repo/pull.go
@@ -290,7 +290,7 @@ func checkPullInfo(ctx *context.Context) *models.Issue {
 
 	if ctx.IsSigned {
 		// Update issue-user.
-		if err = issue.ReadBy(ctx.Doer.ID); err != nil {
+		if err = issue.ReadBy(ctx, ctx.Doer.ID); err != nil {
 			ctx.ServerError("ReadBy", err)
 			return nil
 		}
@@ -866,6 +866,7 @@ func MergePullRequest(ctx *context.Context) {
 	manuallMerge := repo_model.MergeStyle(form.Do) == repo_model.MergeStyleManuallyMerged
 	forceMerge := form.ForceMerge != nil && *form.ForceMerge
 
+	// start with merging by checking
 	if err := pull_service.CheckPullMergable(ctx, ctx.Doer, &ctx.Repo.Permission, pr, manuallMerge, forceMerge); err != nil {
 		if errors.Is(err, pull_service.ErrIsClosed) {
 			if issue.IsPull {
@@ -899,7 +900,6 @@ func MergePullRequest(ctx *context.Context) {
 		} else {
 			ctx.ServerError("WebCheck", err)
 		}
-
 		return
 	}
 
@@ -909,14 +909,12 @@ func MergePullRequest(ctx *context.Context) {
 			if models.IsErrInvalidMergeStyle(err) {
 				ctx.Flash.Error(ctx.Tr("repo.pulls.invalid_merge_option"))
 				ctx.Redirect(issue.Link())
-				return
 			} else if strings.Contains(err.Error(), "Wrong commit ID") {
 				ctx.Flash.Error(ctx.Tr("repo.pulls.wrong_commit_id"))
 				ctx.Redirect(issue.Link())
-				return
+			} else {
+				ctx.ServerError("MergedManually", err)
 			}
-
-			ctx.ServerError("MergedManually", err)
 			return
 		}
 
@@ -925,16 +923,15 @@ func MergePullRequest(ctx *context.Context) {
 	}
 
 	// set defaults to propagate needed fields
-	if err := form.SetDefaults(pr); err != nil {
+	if err := form.SetDefaults(ctx, pr); err != nil {
 		ctx.ServerError("SetDefaults", fmt.Errorf("SetDefaults: %v", err))
 		return
 	}
 
-	if err := pull_service.Merge(ctx, pr, ctx.Doer, ctx.Repo.GitRepo, repo_model.MergeStyle(form.Do), form.HeadCommitID, form.MergeTitleField); err != nil {
+	if err := pull_service.Merge(pr, ctx.Doer, ctx.Repo.GitRepo, repo_model.MergeStyle(form.Do), form.HeadCommitID, form.MergeTitleField); err != nil {
 		if models.IsErrInvalidMergeStyle(err) {
 			ctx.Flash.Error(ctx.Tr("repo.pulls.invalid_merge_option"))
 			ctx.Redirect(issue.Link())
-			return
 		} else if models.IsErrMergeConflicts(err) {
 			conflictError := err.(models.ErrMergeConflicts)
 			flashError, err := ctx.RenderToString(tplAlertDetails, map[string]interface{}{
@@ -948,7 +945,6 @@ func MergePullRequest(ctx *context.Context) {
 			}
 			ctx.Flash.Error(flashError)
 			ctx.Redirect(issue.Link())
-			return
 		} else if models.IsErrRebaseConflicts(err) {
 			conflictError := err.(models.ErrRebaseConflicts)
 			flashError, err := ctx.RenderToString(tplAlertDetails, map[string]interface{}{
@@ -962,22 +958,18 @@ func MergePullRequest(ctx *context.Context) {
 			}
 			ctx.Flash.Error(flashError)
 			ctx.Redirect(issue.Link())
-			return
 		} else if models.IsErrMergeUnrelatedHistories(err) {
 			log.Debug("MergeUnrelatedHistories error: %v", err)
 			ctx.Flash.Error(ctx.Tr("repo.pulls.unrelated_histories"))
 			ctx.Redirect(issue.Link())
-			return
 		} else if git.IsErrPushOutOfDate(err) {
 			log.Debug("MergePushOutOfDate error: %v", err)
 			ctx.Flash.Error(ctx.Tr("repo.pulls.merge_out_of_date"))
 			ctx.Redirect(issue.Link())
-			return
 		} else if models.IsErrSHADoesNotMatch(err) {
 			log.Debug("MergeHeadOutOfDate error: %v", err)
 			ctx.Flash.Error(ctx.Tr("repo.pulls.head_out_of_date"))
 			ctx.Redirect(issue.Link())
-			return
 		} else if git.IsErrPushRejected(err) {
 			log.Debug("MergePushRejected error: %v", err)
 			pushrejErr := err.(*git.ErrPushRejected)
@@ -997,11 +989,12 @@ func MergePullRequest(ctx *context.Context) {
 				ctx.Flash.Error(flashError)
 			}
 			ctx.Redirect(issue.Link())
-			return
+		} else {
+			ctx.ServerError("Merge", err)
 		}
-		ctx.ServerError("Merge", err)
 		return
 	}
+	log.Trace("Pull request merged: %d", pr.ID)
 
 	if err := stopTimerIfAvailable(ctx.Doer, issue); err != nil {
 		ctx.ServerError("CreateOrStopIssueStopwatch", err)
@@ -1012,7 +1005,7 @@ func MergePullRequest(ctx *context.Context) {
 
 	if form.DeleteBranchAfterMerge {
 		// Don't cleanup when other pr use this branch as head branch
-		exist, err := models.HasUnmergedPullRequestsByHeadInfo(pr.HeadRepoID, pr.HeadBranch)
+		exist, err := models.HasUnmergedPullRequestsByHeadInfo(ctx, pr.HeadRepoID, pr.HeadBranch)
 		if err != nil {
 			ctx.ServerError("HasUnmergedPullRequestsByHeadInfo", err)
 			return
@@ -1193,7 +1186,7 @@ func CleanUpPullRequest(ctx *context.Context) {
 	}
 
 	// Don't cleanup when there are other PR's that use this branch as head branch.
-	exist, err := models.HasUnmergedPullRequestsByHeadInfo(pr.HeadRepoID, pr.HeadBranch)
+	exist, err := models.HasUnmergedPullRequestsByHeadInfo(ctx, pr.HeadRepoID, pr.HeadBranch)
 	if err != nil {
 		ctx.ServerError("HasUnmergedPullRequestsByHeadInfo", err)
 		return
@@ -1304,7 +1297,7 @@ func deleteBranch(ctx *context.Context, pr *models.PullRequest, gitRepo *git.Rep
 		return
 	}
 
-	if err := models.AddDeletePRBranchComment(ctx.Doer, pr.BaseRepo, pr.IssueID, pr.HeadBranch); err != nil {
+	if err := models.AddDeletePRBranchComment(ctx, ctx.Doer, pr.BaseRepo, pr.IssueID, pr.HeadBranch); err != nil {
 		// Do not fail here as branch has already been deleted
 		log.Error("DeleteBranch: %v", err)
 	}
diff --git a/services/asymkey/sign.go b/services/asymkey/sign.go
index 876cb7c205..6b17c017fc 100644
--- a/services/asymkey/sign.go
+++ b/services/asymkey/sign.go
@@ -317,7 +317,7 @@ Loop:
 			if protectedBranch == nil {
 				return false, "", nil, &ErrWontSign{approved}
 			}
-			if protectedBranch.GetGrantedApprovalsCount(pr) < 1 {
+			if protectedBranch.GetGrantedApprovalsCount(ctx, pr) < 1 {
 				return false, "", nil, &ErrWontSign{approved}
 			}
 		case baseSigned:
diff --git a/services/forms/repo_form.go b/services/forms/repo_form.go
index f40e99a044..5c3adc1cd3 100644
--- a/services/forms/repo_form.go
+++ b/services/forms/repo_form.go
@@ -6,6 +6,7 @@
 package forms
 
 import (
+	stdContext "context"
 	"net/http"
 	"net/url"
 	"strings"
@@ -601,7 +602,7 @@ func (f *MergePullRequestForm) Validate(req *http.Request, errs binding.Errors)
 }
 
 // SetDefaults if not provided for mergestyle and commit message
-func (f *MergePullRequestForm) SetDefaults(pr *models.PullRequest) (err error) {
+func (f *MergePullRequestForm) SetDefaults(ctx stdContext.Context, pr *models.PullRequest) (err error) {
 	if f.Do == "" {
 		f.Do = "merge"
 	}
@@ -610,9 +611,9 @@ func (f *MergePullRequestForm) SetDefaults(pr *models.PullRequest) (err error) {
 	if len(f.MergeTitleField) == 0 {
 		switch f.Do {
 		case "merge", "rebase-merge":
-			f.MergeTitleField, err = pr.GetDefaultMergeMessage()
+			f.MergeTitleField, err = pr.GetDefaultMergeMessage(ctx)
 		case "squash":
-			f.MergeTitleField, err = pr.GetDefaultSquashMessage()
+			f.MergeTitleField, err = pr.GetDefaultSquashMessage(ctx)
 		}
 	}
 
diff --git a/services/issue/status.go b/services/issue/status.go
index 1af4508b09..d2b4fc303e 100644
--- a/services/issue/status.go
+++ b/services/issue/status.go
@@ -5,6 +5,8 @@
 package issue
 
 import (
+	"context"
+
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/models/db"
 	user_model "code.gitea.io/gitea/models/user"
@@ -14,10 +16,16 @@ import (
 
 // ChangeStatus changes issue status to open or closed.
 func ChangeStatus(issue *models.Issue, doer *user_model.User, closed bool) error {
-	comment, err := models.ChangeIssueStatus(issue, doer, closed)
+	return changeStatusCtx(db.DefaultContext, issue, doer, closed)
+}
+
+// changeStatusCtx changes issue status to open or closed.
+// TODO: if context is not db.DefaultContext we get a deadlock!!!
+func changeStatusCtx(ctx context.Context, issue *models.Issue, doer *user_model.User, closed bool) error {
+	comment, err := models.ChangeIssueStatus(ctx, issue, doer, closed)
 	if err != nil {
 		if models.IsErrDependenciesLeft(err) && closed {
-			if err := models.FinishIssueStopwatchIfPossible(db.DefaultContext, doer, issue); err != nil {
+			if err := models.FinishIssueStopwatchIfPossible(ctx, doer, issue); err != nil {
 				log.Error("Unable to stop stopwatch for issue[%d]#%d: %v", issue.ID, issue.Index, err)
 			}
 		}
@@ -25,7 +33,7 @@ func ChangeStatus(issue *models.Issue, doer *user_model.User, closed bool) error
 	}
 
 	if closed {
-		if err := models.FinishIssueStopwatchIfPossible(db.DefaultContext, doer, issue); err != nil {
+		if err := models.FinishIssueStopwatchIfPossible(ctx, doer, issue); err != nil {
 			return err
 		}
 	}
diff --git a/services/pull/check.go b/services/pull/check.go
index eb3b17d555..64eb93104e 100644
--- a/services/pull/check.go
+++ b/services/pull/check.go
@@ -14,6 +14,7 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/models/unit"
 	user_model "code.gitea.io/gitea/models/user"
@@ -59,70 +60,72 @@ func AddToTaskQueue(pr *models.PullRequest) {
 }
 
 // CheckPullMergable check if the pull mergable based on all conditions (branch protection, merge options, ...)
-func CheckPullMergable(ctx context.Context, doer *user_model.User, perm *models.Permission, pr *models.PullRequest, manuallMerge, force bool) error {
-	if pr.HasMerged {
-		return ErrHasMerged
-	}
+func CheckPullMergable(stdCtx context.Context, doer *user_model.User, perm *models.Permission, pr *models.PullRequest, manuallMerge, force bool) error {
+	return db.WithTx(func(ctx context.Context) error {
+		if pr.HasMerged {
+			return ErrHasMerged
+		}
 
-	if err := pr.LoadIssue(); err != nil {
-		return err
-	} else if pr.Issue.IsClosed {
-		return ErrIsClosed
-	}
+		if err := pr.LoadIssueCtx(ctx); err != nil {
+			return err
+		} else if pr.Issue.IsClosed {
+			return ErrIsClosed
+		}
 
-	if allowedMerge, err := IsUserAllowedToMerge(pr, *perm, doer); err != nil {
-		return err
-	} else if !allowedMerge {
-		return ErrUserNotAllowedToMerge
-	}
+		if allowedMerge, err := IsUserAllowedToMerge(ctx, pr, *perm, doer); err != nil {
+			return err
+		} else if !allowedMerge {
+			return ErrUserNotAllowedToMerge
+		}
 
-	if manuallMerge {
-		// don't check rules to "auto merge", doer is going to mark this pull as merged manually
-		return nil
-	}
+		if manuallMerge {
+			// don't check rules to "auto merge", doer is going to mark this pull as merged manually
+			return nil
+		}
 
-	if pr.IsWorkInProgress() {
-		return ErrIsWorkInProgress
-	}
+		if pr.IsWorkInProgress() {
+			return ErrIsWorkInProgress
+		}
 
-	if !pr.CanAutoMerge() {
-		return ErrNotMergableState
-	}
+		if !pr.CanAutoMerge() {
+			return ErrNotMergableState
+		}
 
-	if pr.IsChecking() {
-		return ErrIsChecking
-	}
+		if pr.IsChecking() {
+			return ErrIsChecking
+		}
 
-	if err := CheckPullBranchProtections(ctx, pr, false); err != nil {
-		if models.IsErrDisallowedToMerge(err) {
-			if force {
-				if isRepoAdmin, err2 := models.IsUserRepoAdmin(pr.BaseRepo, doer); err2 != nil {
-					return err2
-				} else if !isRepoAdmin {
-					return err
+		if err := CheckPullBranchProtections(ctx, pr, false); err != nil {
+			if models.IsErrDisallowedToMerge(err) {
+				if force {
+					if isRepoAdmin, err2 := models.IsUserRepoAdminCtx(ctx, pr.BaseRepo, doer); err2 != nil {
+						return err2
+					} else if !isRepoAdmin {
+						return err
+					}
 				}
+			} else {
+				return err
 			}
-		} else {
-			return err
 		}
-	}
 
-	if _, err := isSignedIfRequired(ctx, pr, doer); err != nil {
-		return err
-	}
+		if _, err := isSignedIfRequired(ctx, pr, doer); err != nil {
+			return err
+		}
 
-	if noDeps, err := models.IssueNoDependenciesLeft(pr.Issue); err != nil {
-		return err
-	} else if !noDeps {
-		return ErrDependenciesLeft
-	}
+		if noDeps, err := models.IssueNoDependenciesLeft(ctx, pr.Issue); err != nil {
+			return err
+		} else if !noDeps {
+			return ErrDependenciesLeft
+		}
 
-	return nil
+		return nil
+	}, stdCtx)
 }
 
 // isSignedIfRequired check if merge will be signed if required
 func isSignedIfRequired(ctx context.Context, pr *models.PullRequest, doer *user_model.User) (bool, error) {
-	if err := pr.LoadProtectedBranch(); err != nil {
+	if err := pr.LoadProtectedBranchCtx(ctx); err != nil {
 		return false, err
 	}
 
@@ -266,7 +269,7 @@ func manuallyMerged(ctx context.Context, pr *models.PullRequest) bool {
 		pr.Merger = merger
 		pr.MergerID = merger.ID
 
-		if merged, err := pr.SetMerged(); err != nil {
+		if merged, err := pr.SetMerged(ctx); err != nil {
 			log.Error("PullRequest[%d].setMerged : %v", pr.ID, err)
 			return false
 		} else if !merged {
diff --git a/services/pull/merge.go b/services/pull/merge.go
index 330dffd5c7..ad93b9779f 100644
--- a/services/pull/merge.go
+++ b/services/pull/merge.go
@@ -17,6 +17,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/models/unit"
 	user_model "code.gitea.io/gitea/models/user"
@@ -34,11 +35,11 @@ import (
 // Merge merges pull request to base repository.
 // Caller should check PR is ready to be merged (review and status checks)
 // FIXME: add repoWorkingPull make sure two merges does not happen at same time.
-func Merge(ctx context.Context, pr *models.PullRequest, doer *user_model.User, baseGitRepo *git.Repository, mergeStyle repo_model.MergeStyle, expectedHeadCommitID, message string) (err error) {
-	if err = pr.LoadHeadRepoCtx(ctx); err != nil {
+func Merge(pr *models.PullRequest, doer *user_model.User, baseGitRepo *git.Repository, mergeStyle repo_model.MergeStyle, expectedHeadCommitID, message string) error {
+	if err := pr.LoadHeadRepo(); err != nil {
 		log.Error("LoadHeadRepo: %v", err)
 		return fmt.Errorf("LoadHeadRepo: %v", err)
-	} else if err = pr.LoadBaseRepoCtx(ctx); err != nil {
+	} else if err := pr.LoadBaseRepo(); err != nil {
 		log.Error("LoadBaseRepo: %v", err)
 		return fmt.Errorf("LoadBaseRepo: %v", err)
 	}
@@ -59,7 +60,9 @@ func Merge(ctx context.Context, pr *models.PullRequest, doer *user_model.User, b
 		go AddTestPullRequestTask(doer, pr.BaseRepo.ID, pr.BaseBranch, false, "", "")
 	}()
 
-	pr.MergedCommitID, err = rawMerge(ctx, pr, doer, mergeStyle, expectedHeadCommitID, message)
+	// TODO: make it able to do this in a database session
+	mergeCtx := context.Background()
+	pr.MergedCommitID, err = rawMerge(mergeCtx, pr, doer, mergeStyle, expectedHeadCommitID, message)
 	if err != nil {
 		return err
 	}
@@ -68,18 +71,18 @@ func Merge(ctx context.Context, pr *models.PullRequest, doer *user_model.User, b
 	pr.Merger = doer
 	pr.MergerID = doer.ID
 
-	if _, err := pr.SetMerged(); err != nil {
+	if _, err := pr.SetMerged(db.DefaultContext); err != nil {
 		log.Error("setMerged [%d]: %v", pr.ID, err)
 	}
 
-	if err := pr.LoadIssue(); err != nil {
+	if err := pr.LoadIssueCtx(db.DefaultContext); err != nil {
 		log.Error("loadIssue [%d]: %v", pr.ID, err)
 	}
 
-	if err := pr.Issue.LoadRepo(ctx); err != nil {
+	if err := pr.Issue.LoadRepo(db.DefaultContext); err != nil {
 		log.Error("loadRepo for issue [%d]: %v", pr.ID, err)
 	}
-	if err := pr.Issue.Repo.GetOwner(ctx); err != nil {
+	if err := pr.Issue.Repo.GetOwner(db.DefaultContext); err != nil {
 		log.Error("GetOwner for issue repo [%d]: %v", pr.ID, err)
 	}
 
@@ -89,17 +92,17 @@ func Merge(ctx context.Context, pr *models.PullRequest, doer *user_model.User, b
 	cache.Remove(pr.Issue.Repo.GetCommitsCountCacheKey(pr.BaseBranch, true))
 
 	// Resolve cross references
-	refs, err := pr.ResolveCrossReferences()
+	refs, err := pr.ResolveCrossReferences(db.DefaultContext)
 	if err != nil {
 		log.Error("ResolveCrossReferences: %v", err)
 		return nil
 	}
 
 	for _, ref := range refs {
-		if err = ref.LoadIssue(); err != nil {
+		if err = ref.LoadIssueCtx(db.DefaultContext); err != nil {
 			return err
 		}
-		if err = ref.Issue.LoadRepo(ctx); err != nil {
+		if err = ref.Issue.LoadRepo(db.DefaultContext); err != nil {
 			return err
 		}
 		close := ref.RefAction == references.XRefActionCloses
@@ -112,7 +115,6 @@ func Merge(ctx context.Context, pr *models.PullRequest, doer *user_model.User, b
 			}
 		}
 	}
-
 	return nil
 }
 
@@ -504,6 +506,8 @@ func rawMerge(ctx context.Context, pr *models.PullRequest, doer *user_model.User
 	}
 
 	// Push back to upstream.
+	// TODO: this cause an api call to "/api/internal/hook/post-receive/...",
+	//       that prevents us from doint the whole merge in one db transaction
 	if err := pushCmd.Run(&git.RunOpts{
 		Env:    env,
 		Dir:    tmpBasePath,
@@ -645,17 +649,17 @@ func getDiffTree(ctx context.Context, repoPath, baseBranch, headBranch string) (
 }
 
 // IsUserAllowedToMerge check if user is allowed to merge PR with given permissions and branch protections
-func IsUserAllowedToMerge(pr *models.PullRequest, p models.Permission, user *user_model.User) (bool, error) {
+func IsUserAllowedToMerge(ctx context.Context, pr *models.PullRequest, p models.Permission, user *user_model.User) (bool, error) {
 	if user == nil {
 		return false, nil
 	}
 
-	err := pr.LoadProtectedBranch()
+	err := pr.LoadProtectedBranchCtx(ctx)
 	if err != nil {
 		return false, err
 	}
 
-	if (p.CanWrite(unit.TypeCode) && pr.ProtectedBranch == nil) || (pr.ProtectedBranch != nil && models.IsUserMergeWhitelisted(pr.ProtectedBranch, user.ID, p)) {
+	if (p.CanWrite(unit.TypeCode) && pr.ProtectedBranch == nil) || (pr.ProtectedBranch != nil && models.IsUserMergeWhitelisted(ctx, pr.ProtectedBranch, user.ID, p)) {
 		return true, nil
 	}
 
@@ -668,7 +672,7 @@ func CheckPullBranchProtections(ctx context.Context, pr *models.PullRequest, ski
 		return fmt.Errorf("LoadBaseRepo: %v", err)
 	}
 
-	if err = pr.LoadProtectedBranch(); err != nil {
+	if err = pr.LoadProtectedBranchCtx(ctx); err != nil {
 		return fmt.Errorf("LoadProtectedBranch: %v", err)
 	}
 	if pr.ProtectedBranch == nil {
@@ -685,17 +689,17 @@ func CheckPullBranchProtections(ctx context.Context, pr *models.PullRequest, ski
 		}
 	}
 
-	if !pr.ProtectedBranch.HasEnoughApprovals(pr) {
+	if !pr.ProtectedBranch.HasEnoughApprovals(ctx, pr) {
 		return models.ErrDisallowedToMerge{
 			Reason: "Does not have enough approvals",
 		}
 	}
-	if pr.ProtectedBranch.MergeBlockedByRejectedReview(pr) {
+	if pr.ProtectedBranch.MergeBlockedByRejectedReview(ctx, pr) {
 		return models.ErrDisallowedToMerge{
 			Reason: "There are requested changes",
 		}
 	}
-	if pr.ProtectedBranch.MergeBlockedByOfficialReviewRequests(pr) {
+	if pr.ProtectedBranch.MergeBlockedByOfficialReviewRequests(ctx, pr) {
 		return models.ErrDisallowedToMerge{
 			Reason: "There are official review requests",
 		}
@@ -721,52 +725,58 @@ func CheckPullBranchProtections(ctx context.Context, pr *models.PullRequest, ski
 }
 
 // MergedManually mark pr as merged manually
-func MergedManually(pr *models.PullRequest, doer *user_model.User, baseGitRepo *git.Repository, commitID string) (err error) {
-	prUnit, err := pr.BaseRepo.GetUnit(unit.TypePullRequests)
-	if err != nil {
-		return
-	}
-	prConfig := prUnit.PullRequestsConfig()
-
-	// Check if merge style is correct and allowed
-	if !prConfig.IsMergeStyleAllowed(repo_model.MergeStyleManuallyMerged) {
-		return models.ErrInvalidMergeStyle{ID: pr.BaseRepo.ID, Style: repo_model.MergeStyleManuallyMerged}
-	}
+func MergedManually(pr *models.PullRequest, doer *user_model.User, baseGitRepo *git.Repository, commitID string) error {
+	if err := db.WithTx(func(ctx context.Context) error {
+		prUnit, err := pr.BaseRepo.GetUnitCtx(ctx, unit.TypePullRequests)
+		if err != nil {
+			return err
+		}
+		prConfig := prUnit.PullRequestsConfig()
 
-	if len(commitID) < 40 {
-		return fmt.Errorf("Wrong commit ID")
-	}
+		// Check if merge style is correct and allowed
+		if !prConfig.IsMergeStyleAllowed(repo_model.MergeStyleManuallyMerged) {
+			return models.ErrInvalidMergeStyle{ID: pr.BaseRepo.ID, Style: repo_model.MergeStyleManuallyMerged}
+		}
 
-	commit, err := baseGitRepo.GetCommit(commitID)
-	if err != nil {
-		if git.IsErrNotExist(err) {
+		if len(commitID) < 40 {
 			return fmt.Errorf("Wrong commit ID")
 		}
-		return
-	}
 
-	ok, err := baseGitRepo.IsCommitInBranch(commitID, pr.BaseBranch)
-	if err != nil {
-		return
-	}
-	if !ok {
-		return fmt.Errorf("Wrong commit ID")
-	}
+		commit, err := baseGitRepo.GetCommit(commitID)
+		if err != nil {
+			if git.IsErrNotExist(err) {
+				return fmt.Errorf("Wrong commit ID")
+			}
+			return err
+		}
+		commitID = commit.ID.String()
 
-	pr.MergedCommitID = commitID
-	pr.MergedUnix = timeutil.TimeStamp(commit.Author.When.Unix())
-	pr.Status = models.PullRequestStatusManuallyMerged
-	pr.Merger = doer
-	pr.MergerID = doer.ID
+		ok, err := baseGitRepo.IsCommitInBranch(commitID, pr.BaseBranch)
+		if err != nil {
+			return err
+		}
+		if !ok {
+			return fmt.Errorf("Wrong commit ID")
+		}
 
-	merged := false
-	if merged, err = pr.SetMerged(); err != nil {
-		return
-	} else if !merged {
-		return fmt.Errorf("SetMerged failed")
+		pr.MergedCommitID = commitID
+		pr.MergedUnix = timeutil.TimeStamp(commit.Author.When.Unix())
+		pr.Status = models.PullRequestStatusManuallyMerged
+		pr.Merger = doer
+		pr.MergerID = doer.ID
+
+		merged := false
+		if merged, err = pr.SetMerged(ctx); err != nil {
+			return err
+		} else if !merged {
+			return fmt.Errorf("SetMerged failed")
+		}
+		return nil
+	}); err != nil {
+		return err
 	}
 
 	notification.NotifyMergePullRequest(pr, doer)
-	log.Info("manuallyMerged[%d]: Marked as manually merged into %s/%s by commit id: %s", pr.ID, pr.BaseRepo.Name, pr.BaseBranch, commit.ID.String())
+	log.Info("manuallyMerged[%d]: Marked as manually merged into %s/%s by commit id: %s", pr.ID, pr.BaseRepo.Name, pr.BaseBranch, commitID)
 	return nil
 }
diff --git a/services/pull/update.go b/services/pull/update.go
index 2d845e8504..08ff1cedfc 100644
--- a/services/pull/update.go
+++ b/services/pull/update.go
@@ -116,13 +116,13 @@ func IsUserAllowedToUpdate(ctx context.Context, pull *models.PullRequest, user *
 		return false, false, err
 	}
 
-	mergeAllowed, err = IsUserAllowedToMerge(pr, headRepoPerm, user)
+	mergeAllowed, err = IsUserAllowedToMerge(ctx, pr, headRepoPerm, user)
 	if err != nil {
 		return false, false, err
 	}
 
 	if pull.AllowMaintainerEdit {
-		mergeAllowedMaintainer, err := IsUserAllowedToMerge(pr, baseRepoPerm, user)
+		mergeAllowedMaintainer, err := IsUserAllowedToMerge(ctx, pr, baseRepoPerm, user)
 		if err != nil {
 			return false, false, err
 		}
diff --git a/templates/repo/issue/view_content/pull.tmpl b/templates/repo/issue/view_content/pull.tmpl
index fef868af1f..8c43ace32e 100644
--- a/templates/repo/issue/view_content/pull.tmpl
+++ b/templates/repo/issue/view_content/pull.tmpl
@@ -329,7 +329,7 @@
 									{{.CsrfTokenHtml}}
 									<input type="hidden" name="head_commit_id" value="{{.PullHeadCommitID}}">
 									<div class="field">
-										<input type="text" name="merge_title_field" value="{{.Issue.PullRequest.GetDefaultMergeMessage}}">
+										<input type="text" name="merge_title_field" value="{{.Issue.PullRequest.GetDefaultMergeMessage $.Context}}">
 									</div>
 									<div class="field">
 										<textarea name="merge_message_field" rows="5" placeholder="{{$.i18n.Tr "repo.editor.commit_message_desc"}}">Reviewed-on: {{$.Issue.HTMLURL}}&#13;&#10;{{$approvers}}</textarea>
@@ -375,7 +375,7 @@
 									{{.CsrfTokenHtml}}
 									<input type="hidden" name="head_commit_id" value="{{.PullHeadCommitID}}">
 									<div class="field">
-										<input type="text" name="merge_title_field" value="{{.Issue.PullRequest.GetDefaultMergeMessage}}">
+										<input type="text" name="merge_title_field" value="{{.Issue.PullRequest.GetDefaultMergeMessage $.Context}}">
 									</div>
 									<div class="field">
 										<textarea name="merge_message_field" rows="5" placeholder="{{$.i18n.Tr "repo.editor.commit_message_desc"}}">Reviewed-on: {{$.Issue.HTMLURL}}&#13;&#10;{{$approvers}}</textarea>
@@ -401,7 +401,7 @@
 									{{.CsrfTokenHtml}}
 									<input type="hidden" name="head_commit_id" value="{{.PullHeadCommitID}}">
 									<div class="field">
-										<input type="text" name="merge_title_field" value="{{.Issue.PullRequest.GetDefaultSquashMessage}}">
+										<input type="text" name="merge_title_field" value="{{.Issue.PullRequest.GetDefaultSquashMessage $.Context}}">
 									</div>
 									<div class="field">
 										<textarea name="merge_message_field" rows="5" placeholder="{{$.i18n.Tr "repo.editor.commit_message_desc"}}">{{.GetCommitMessages}}Reviewed-on: {{$.Issue.HTMLURL}}&#13;&#10;{{$approvers}}</textarea>