fix: remove artificial delay for PR update (#7773)

- I was not able to find a reasoning in the pull request (https://github.com/go-gitea/gitea/pull/9784) for the existence of this `time.Sleep`. The best I could come up with during manual testing is that there's a brief moment where 'this pull request is missing fork information' is shown, this was caused by an incorrect condition.
- Added integration test.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/7773
Reviewed-by: 0ko <0ko@noreply.codeberg.org>
Reviewed-by: Otto <otto@codeberg.org>
Co-authored-by: Gusted <postmaster@gusted.xyz>
Co-committed-by: Gusted <postmaster@gusted.xyz>

models/fixtures/pull_request.yml

@@ -65,6 +65,7 @@
   merge_base: 985f0301dba5e7b34be866819cd15ad3d8f508ee
   has_merged: false
   allow_maintainer_edit: true
+  commits_behind: 1
 
 -
   id: 6

routers/web/repo/pull.go

@@ -14,7 +14,6 @@ import (
 	"net/url"
 	"strconv"
 	"strings"
-	"time"
 
 	"forgejo.org/models"
 	activities_model "forgejo.org/models/activities"
@@ -728,7 +727,7 @@ func PrepareViewPullInfo(ctx *context.Context, issue *issues_model.Issue) *git.C
 	ctx.Data["HeadBranchCommitID"] = headBranchSha
 	ctx.Data["PullHeadCommitID"] = sha
 
-	if pull.HeadRepo == nil || !headBranchExist || (!pull.Issue.IsClosed && (headBranchSha != sha)) {
+	if pull.HeadRepo == nil || !headBranchExist || (!pull.Issue.IsClosed && !pull.IsChecking() && (headBranchSha != sha)) {
 		ctx.Data["IsPullRequestBroken"] = true
 		if pull.IsSameRepo() {
 			ctx.Data["HeadTarget"] = pull.HeadBranch
@@ -1208,8 +1207,6 @@ func UpdatePullRequest(ctx *context.Context) {
 		return
 	}
 
-	time.Sleep(1 * time.Second)
-
 	ctx.Flash.Success(ctx.Tr("repo.pulls.update_branch_success"))
 	ctx.Redirect(issue.Link())
 }

tests/integration/pull_update_test.go

@@ -273,3 +273,19 @@ func createOutdatedPR(t *testing.T, actor, forkOrg *user_model.User) *issues_mod
 
 	return issue.PullRequest
 }
+
+func TestStatusDuringUpdate(t *testing.T) {
+	onGiteaRun(t, func(t *testing.T, u *url.URL) {
+		session := loginUser(t, "user2")
+
+		// Adjust this pull request to be in the conflict checker and having a head
+		// branch that is pointing to the an incorrect commit ID.
+		_, err := db.GetEngine(t.Context()).Cols("status", "head_branch").Update(&issues_model.PullRequest{ID: 5, Status: issues_model.PullRequestStatusChecking, HeadBranch: "master"})
+		require.NoError(t, err)
+
+		resp := session.MakeRequest(t, NewRequest(t, "GET", "/user2/repo1/pulls/5"), http.StatusOK)
+		htmlDoc := NewHTMLParser(t, resp.Body)
+
+		assert.Contains(t, htmlDoc.Find(".merge-section .item").Text(), "Merge conflict checking is in progress. Try again in few moments.")
+	})
+}