From 4c34bc111ce020161a2fbd962a19a9123b3e2dc4 Mon Sep 17 00:00:00 2001
From: Lunny Xiao <xiaolunwen@gmail.com>
Date: Fri, 26 Apr 2019 11:03:39 +0800
Subject: [PATCH] fix pulls broken when fork repository deleted (#6754)

* fix pulls broken when fork repository deleted

* fix lint
---
 models/error.go       | 18 ++++++++++++++++++
 models/pull.go        |  4 ++++
 routers/repo/issue.go |  7 ++++++-
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/models/error.go b/models/error.go
index 6458594a03d..febe3f3e04c 100644
--- a/models/error.go
+++ b/models/error.go
@@ -1091,6 +1091,24 @@ func (err ErrPullRequestAlreadyExists) Error() string {
 		err.ID, err.IssueID, err.HeadRepoID, err.BaseRepoID, err.HeadBranch, err.BaseBranch)
 }
 
+// ErrPullRequestHeadRepoMissing represents a "ErrPullRequestHeadRepoMissing" error
+type ErrPullRequestHeadRepoMissing struct {
+	ID         int64
+	HeadRepoID int64
+}
+
+// IsErrErrPullRequestHeadRepoMissing checks if an error is a ErrPullRequestHeadRepoMissing.
+func IsErrErrPullRequestHeadRepoMissing(err error) bool {
+	_, ok := err.(ErrPullRequestHeadRepoMissing)
+	return ok
+}
+
+// Error does pretty-printing :D
+func (err ErrPullRequestHeadRepoMissing) Error() string {
+	return fmt.Sprintf("pull request head repo missing [id: %d, head_repo_id: %d]",
+		err.ID, err.HeadRepoID)
+}
+
 // ErrInvalidMergeStyle represents an error if merging with disabled merge strategy
 type ErrInvalidMergeStyle struct {
 	ID    int64
diff --git a/models/pull.go b/models/pull.go
index d059081a44a..71a2439b2c3 100644
--- a/models/pull.go
+++ b/models/pull.go
@@ -299,6 +299,10 @@ func (pr *PullRequest) GetLastCommitStatus() (status *CommitStatus, err error) {
 		return nil, err
 	}
 
+	if pr.HeadRepo == nil {
+		return nil, ErrPullRequestHeadRepoMissing{pr.ID, pr.HeadRepoID}
+	}
+
 	headGitRepo, err := git.OpenRepository(pr.HeadRepo.RepoPath())
 	if err != nil {
 		return nil, err
diff --git a/routers/repo/issue.go b/routers/repo/issue.go
index 42661ef738a..4b76bf5ad97 100644
--- a/routers/repo/issue.go
+++ b/routers/repo/issue.go
@@ -223,7 +223,12 @@ func issues(ctx *context.Context, milestoneID int64, isPullOption util.OptionalB
 			return
 		}
 
-		if isPullOption == util.OptionalBoolTrue {
+		if issues[i].IsPull {
+			if err := issues[i].LoadPullRequest(); err != nil {
+				ctx.ServerError("LoadPullRequest", err)
+				return
+			}
+
 			commitStatus[issues[i].PullRequest.ID], _ = issues[i].PullRequest.GetLastCommitStatus()
 		}
 	}