fix 500 when reviewer is deleted with integration tests (#6856)

integrations/pull_review_test.go

+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+package integrations
+
+import (
+	"net/http"
+	"testing"
+)
+
+func TestPullView_ReviewerMissed(t *testing.T) {
+	prepareTestEnv(t)
+	session := loginUser(t, "user1")
+
+	req := NewRequest(t, "GET", "/pulls")
+	session.MakeRequest(t, req, http.StatusOK)
+
+	req = NewRequest(t, "GET", "/user2/repo1/pulls/3")
+	session.MakeRequest(t, req, http.StatusOK)
+}

models/fixtures/comment.yml

   tree_path: "README.md"
   created_unix: 946684812
   invalidated: true
+
+-
+  id: 7
+  type: 21 # code comment
+  poster_id: 100
+  issue_id: 3
+  content: "a review from a deleted user"
+  line: -4
+  review_id: 10
+  tree_path: "README.md"
+  created_unix: 946684812
+  invalidated: true

models/fixtures/review.yml

   content: "New review 3 rejected"
   updated_unix: 946684810
   created_unix: 946684810
+
+-
+  id: 10
+  type: 3
+  reviewer_id: 100
+  issue_id: 3
+  content: "a deleted user's review"
+  updated_unix: 946684810
+  created_unix: 946684810

models/issue_comment.go

 			return err
 		}
 	}
+	c.Review.Issue = c.Issue
 	return nil
 }
 

routers/repo/issue.go

 	// Render comments and and fetch participants.
 	participants[0] = issue.Poster
 	for _, comment = range issue.Comments {
+		comment.Issue = issue
+
 		if err := comment.LoadPoster(); err != nil {
 			ctx.ServerError("LoadPoster", err)
 			return
 				continue
 			}
 			if err = comment.Review.LoadAttributes(); err != nil {
-				ctx.ServerError("Review.LoadAttributes", err)
-				return
+				if !models.IsErrUserNotExist(err) {
+					ctx.ServerError("Review.LoadAttributes", err)
+					return
+				}
+				comment.Review.Reviewer = models.NewGhostUser()
 			}
 			if err = comment.Review.LoadCodeComments(); err != nil {
 				ctx.ServerError("Review.LoadCodeComments", err)