Refresh the refernce of the closed PR when reopening (#24231)

Close #24213 
Replace #23830

#### Cause

- Before, in order to making PR can get latest commit after reopening,
the `ref`(${REPO_PATH}/refs/pull/${PR_INDEX}/head) of evrey closed PR
will be updated when pushing commits to the `head branch` of the closed
PR.

#### Changes

- For closed PR , won't perform these behavior: insert`comment`, push
`notification` (UI and email), exectue
[pushToBaseRepo](https://github.com/go-gitea/gitea/blob/74225033413dc0f2b308bbe069f6d185b551e364/services/pull/pull.go#L409)
function and trigger `action` any more when pushing to the `head branch`
of the closed PR.
- Refresh the reference of the PR when reopening the closed PR (**even
if the head branch has been deleted before**). Make the reference of PR
consistent with the `head branch`.

Author: sillyguodong

Diff for: models/issues/pull.go

@@ -433,6 +433,10 @@ func (pr *PullRequest) GetGitRefName() string {
 	return fmt.Sprintf("%s%d/head", git.PullPrefix, pr.Index)
 }
 
+func (pr *PullRequest) GetGitHeadBranchRefName() string {
+	return fmt.Sprintf("%s%s", git.BranchPrefix, pr.HeadBranch)
+}
+
 // IsChecking returns true if this pull request is still checking conflict.
 func (pr *PullRequest) IsChecking() bool {
 	return pr.Status == PullRequestStatusChecking

Diff for: models/issues/pull_list.go

@@ -51,16 +51,11 @@ func listPullRequestStatement(baseRepoID int64, opts *PullRequestsOptions) (*xor
 }
 
 // GetUnmergedPullRequestsByHeadInfo returns all pull requests that are open and has not been merged
-// by given head information (repo and branch).
-// arg `includeClosed` controls whether the SQL returns closed PRs
-func GetUnmergedPullRequestsByHeadInfo(repoID int64, branch string, includeClosed bool) ([]*PullRequest, error) {
+func GetUnmergedPullRequestsByHeadInfo(repoID int64, branch string) ([]*PullRequest, error) {
 	prs := make([]*PullRequest, 0, 2)
 	sess := db.GetEngine(db.DefaultContext).
 		Join("INNER", "issue", "issue.id = pull_request.issue_id").
-		Where("head_repo_id = ? AND head_branch = ? AND has_merged = ? AND flow = ?", repoID, branch, false, PullRequestFlowGithub)
-	if !includeClosed {
-		sess.Where("issue.is_closed = ?", false)
-	}
+		Where("head_repo_id = ? AND head_branch = ? AND has_merged = ? AND issue.is_closed = ? AND flow = ?", repoID, branch, false, false, PullRequestFlowGithub)
 	return prs, sess.Find(&prs)
 }
 
@@ -74,7 +69,7 @@ func CanMaintainerWriteToBranch(p access_model.Permission, branch string, user *
 		return false
 	}
 
-	prs, err := GetUnmergedPullRequestsByHeadInfo(p.Units[0].RepoID, branch, false)
+	prs, err := GetUnmergedPullRequestsByHeadInfo(p.Units[0].RepoID, branch)
 	if err != nil {
 		return false
 	}

Diff for: models/issues/pull_test.go

@@ -118,7 +118,7 @@ func TestHasUnmergedPullRequestsByHeadInfo(t *testing.T) {
 
 func TestGetUnmergedPullRequestsByHeadInfo(t *testing.T) {
 	assert.NoError(t, unittest.PrepareTestDatabase())
-	prs, err := issues_model.GetUnmergedPullRequestsByHeadInfo(1, "branch2", false)
+	prs, err := issues_model.GetUnmergedPullRequestsByHeadInfo(1, "branch2")
 	assert.NoError(t, err)
 	assert.Len(t, prs, 1)
 	for _, pr := range prs {

Diff for: routers/web/repo/issue.go

@@ -37,6 +37,7 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/markup"
 	"code.gitea.io/gitea/modules/markup/markdown"
+	repo_module "code.gitea.io/gitea/modules/repository"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/templates/vars"
@@ -2784,7 +2785,8 @@ func NewComment(ctx *context.Context) {
 				pr, err = issues_model.GetUnmergedPullRequest(ctx, pull.HeadRepoID, pull.BaseRepoID, pull.HeadBranch, pull.BaseBranch, pull.Flow)
 				if err != nil {
 					if !issues_model.IsErrPullRequestNotExist(err) {
-						ctx.ServerError("GetUnmergedPullRequest", err)
+						ctx.Flash.Error(ctx.Tr("repo.issues.dependency.pr_close_blocked"))
+						ctx.Redirect(fmt.Sprintf("%s/pulls/%d", ctx.Repo.RepoLink, pull.Index))
 						return
 					}
 				}
@@ -2794,6 +2796,57 @@ func NewComment(ctx *context.Context) {
 					issue.PullRequest.HeadCommitID = ""
 					pull_service.AddToTaskQueue(issue.PullRequest)
 				}
+
+				// check whether the ref of PR <refs/pulls/pr_index/head> in base repo is consistent with the head commit of head branch in the head repo
+				// get head commit of PR
+				prHeadRef := pull.GetGitRefName()
+				if err := pull.LoadBaseRepo(ctx); err != nil {
+					ctx.ServerError("Unable to load base repo", err)
+					return
+				}
+				prHeadCommitID, err := git.GetFullCommitID(ctx, pull.BaseRepo.RepoPath(), prHeadRef)
+				if err != nil {
+					ctx.ServerError("Get head commit Id of pr fail", err)
+					return
+				}
+
+				// get head commit of branch in the head repo
+				if err := pull.LoadHeadRepo(ctx); err != nil {
+					ctx.ServerError("Unable to load head repo", err)
+					return
+				}
+				if ok := git.IsBranchExist(ctx, pull.HeadRepo.RepoPath(), pull.BaseBranch); !ok {
+					// todo localize
+					ctx.Flash.Error("The origin branch is delete, cannot reopen.")
+					ctx.Redirect(fmt.Sprintf("%s/pulls/%d", ctx.Repo.RepoLink, pull.Index))
+					return
+				}
+				headBranchRef := pull.GetGitHeadBranchRefName()
+				headBranchCommitID, err := git.GetFullCommitID(ctx, pull.HeadRepo.RepoPath(), headBranchRef)
+				if err != nil {
+					ctx.ServerError("Get head commit Id of head branch fail", err)
+					return
+				}
+
+				err = pull.LoadIssue(ctx)
+				if err != nil {
+					ctx.ServerError("load the issue of pull request error", err)
+					return
+				}
+
+				if prHeadCommitID != headBranchCommitID {
+					// force push to base repo
+					err := git.Push(ctx, pull.HeadRepo.RepoPath(), git.PushOptions{
+						Remote: pull.BaseRepo.RepoPath(),
+						Branch: pull.HeadBranch + ":" + prHeadRef,
+						Force:  true,
+						Env:    repo_module.InternalPushingEnvironment(pull.Issue.Poster, pull.BaseRepo),
+					})
+					if err != nil {
+						ctx.ServerError("force push error", err)
+						return
+					}
+				}
 			}
 
 			if pr != nil {
@@ -2822,6 +2875,7 @@ func NewComment(ctx *context.Context) {
 					log.Trace("Issue [%d] status changed to closed: %v", issue.ID, issue.IsClosed)
 				}
 			}
+
 		}
 
 		// Redirect to comment hashtag if there is any actual content.

Diff for: services/pull/pull.go

@@ -257,7 +257,8 @@ func AddTestPullRequestTask(doer *user_model.User, repoID int64, branch string,
 		// If you don't let it run all the way then you will lose data
 		// TODO: graceful: AddTestPullRequestTask needs to become a queue!
 
-		prs, err := issues_model.GetUnmergedPullRequestsByHeadInfo(repoID, branch, true)
+		// GetUnmergedPullRequestsByHeadInfo() only return open and unmerged PR.
+		prs, err := issues_model.GetUnmergedPullRequestsByHeadInfo(repoID, branch)
 		if err != nil {
 			log.Error("Find pull requests [head_repo_id: %d, head_branch: %s]: %v", repoID, branch, err)
 			return
@@ -274,12 +275,9 @@ func AddTestPullRequestTask(doer *user_model.User, repoID int64, branch string,
 				continue
 			}
 
-			// If the PR is closed, someone still push some commits to the PR,
-			// 1. We will insert comments of commits, but hidden until the PR is reopened.
-			// 2. We won't send any notification.
 			AddToTaskQueue(pr)
 			comment, err := CreatePushPullComment(ctx, doer, pr, oldCommitID, newCommitID)
-			if err == nil && comment != nil && !pr.Issue.IsClosed {
+			if err == nil && comment != nil {
 				notification.NotifyPullRequestPushCommits(ctx, doer, pr, comment)
 			}
 		}
@@ -294,10 +292,6 @@ func AddTestPullRequestTask(doer *user_model.User, repoID int64, branch string,
 			}
 			if err == nil {
 				for _, pr := range prs {
-					if pr.Issue.IsClosed {
-						// The closed PR never trigger action or webhook
-						continue
-					}
 					if newCommitID != "" && newCommitID != git.EmptySHA {
 						changed, err := checkIfPRContentChanged(ctx, pr, oldCommitID, newCommitID)
 						if err != nil {
@@ -503,7 +497,7 @@ func (errs errlist) Error() string {
 
 // CloseBranchPulls close all the pull requests who's head branch is the branch
 func CloseBranchPulls(doer *user_model.User, repoID int64, branch string) error {
-	prs, err := issues_model.GetUnmergedPullRequestsByHeadInfo(repoID, branch, false)
+	prs, err := issues_model.GetUnmergedPullRequestsByHeadInfo(repoID, branch)
 	if err != nil {
 		return err
 	}
@@ -539,7 +533,7 @@ func CloseRepoBranchesPulls(ctx context.Context, doer *user_model.User, repo *re
 
 	var errs errlist
 	for _, branch := range branches {
-		prs, err := issues_model.GetUnmergedPullRequestsByHeadInfo(repo.ID, branch.Name, false)
+		prs, err := issues_model.GetUnmergedPullRequestsByHeadInfo(repo.ID, branch.Name)
 		if err != nil {
 			return err
 		}