[BugFix] [API] Pull.API.Convert: Only try to get HeadBranch if HeadRepo exist (#10029) (#10088)

models/pull.go

@@ -420,7 +420,7 @@ func (pr *PullRequest) apiFormat(e Engine) *api.PullRequest {
 		err        error
 	)
 	if err = pr.Issue.loadRepo(e); err != nil {
-		log.Error("loadRepo[%d]: %v", pr.ID, err)
+		log.Error("pr.Issue.loadRepo[%d]: %v", pr.ID, err)
 		return nil
 	}
 	apiIssue := pr.Issue.apiFormat(e)
@@ -431,19 +431,14 @@ func (pr *PullRequest) apiFormat(e Engine) *api.PullRequest {
 			return nil
 		}
 	}
-	if pr.HeadRepo == nil {
+	if pr.HeadRepoID != 0 && pr.HeadRepo == nil {
 		pr.HeadRepo, err = getRepositoryByID(e, pr.HeadRepoID)
-		if err != nil {
+		if err != nil && !IsErrRepoNotExist(err) {
 			log.Error("GetRepositoryById[%d]: %v", pr.ID, err)
 			return nil
 		}
 	}
 
-	if err = pr.Issue.loadRepo(e); err != nil {
-		log.Error("pr.Issue.loadRepo[%d]: %v", pr.ID, err)
-		return nil
-	}
-
 	apiPullRequest := &api.PullRequest{
 		ID:        pr.ID,
 		URL:       pr.Issue.HTMLURL(),
@@ -495,6 +490,7 @@ func (pr *PullRequest) apiFormat(e Engine) *api.PullRequest {
 		apiPullRequest.Base = apiBaseBranchInfo
 	}
 
+	if pr.HeadRepo != nil {
 		headBranch, err = pr.HeadRepo.GetBranch(pr.HeadBranch)
 		if err != nil {
 			if git.IsErrBranchNotExist(err) {
@@ -523,6 +519,13 @@ func (pr *PullRequest) apiFormat(e Engine) *api.PullRequest {
 			}
 			apiPullRequest.Head = apiHeadBranchInfo
 		}
+	} else {
+		apiPullRequest.Head = &api.PRBranchInfo{
+			Name:   pr.HeadBranch,
+			Ref:    fmt.Sprintf("refs/pull/%d/head", pr.Index),
+			RepoID: -1,
+		}
+	}
 
 	if pr.Status != PullRequestStatusChecking {
 		mergeable := !(pr.Status == PullRequestStatusConflict || pr.Status == PullRequestStatusError) && !pr.IsWorkInProgress()