Prevent NPE whilst migrating if there is a team request review (#19855)

A pr.Reviewer may be nil when migrating from Gitea if this is a team
request review.

We do not migrate teams therefore we cannot map these requests, but we can
migrate user requests.

Signed-off-by: Andrew Thornton <art27@cantab.net>

services/migrations/error.go

@@ -8,7 +8,7 @@ package migrations
 import (
 	"errors"
 
-	"github.com/google/go-github/v39/github"
+	"github.com/google/go-github/v45/github"
 )
 
 // ErrRepoNotCreated returns the error that repository not created

services/migrations/gitea_downloader.go

@@ -639,6 +639,11 @@ func (g *GiteaDownloader) GetReviews(reviewable base.Reviewable) ([]*base.Review
 		}
 
 		for _, pr := range prl {
+			if pr.Reviewer == nil {
+				// Presumably this is a team review which we cannot migrate at present but we have to skip this review as otherwise the review will be mapped on to an incorrect user.
+				// TODO: handle team reviews
+				continue
+			}
 
 			rcl, _, err := g.client.ListPullReviewComments(g.repoOwner, g.repoName, reviewable.GetForeignIndex(), pr.ID)
 			if err != nil {
@@ -664,7 +669,7 @@ func (g *GiteaDownloader) GetReviews(reviewable base.Reviewable) ([]*base.Review
 				})
 			}
 
-			allReviews = append(allReviews, &base.Review{
+			review := &base.Review{
 				ID:           pr.ID,
 				IssueIndex:   reviewable.GetLocalIndex(),
 				ReviewerID:   pr.Reviewer.ID,
@@ -675,7 +680,9 @@ func (g *GiteaDownloader) GetReviews(reviewable base.Reviewable) ([]*base.Review
 				CreatedAt:    pr.Submitted,
 				State:        string(pr.State),
 				Comments:     reviewComments,
-			})
+			}
+
+			allReviews = append(allReviews, review)
 		}
 
 		if len(prl) < g.maxPerPage {

services/migrations/gitea_uploader.go

@@ -696,6 +696,8 @@ func convertReviewState(state string) models.ReviewType {
 		return models.ReviewTypeReject
 	case base.ReviewStateCommented:
 		return models.ReviewTypeComment
+	case base.ReviewStateRequestReview:
+		return models.ReviewTypeRequest
 	default:
 		return models.ReviewTypePending
 	}

services/migrations/github.go

@@ -21,7 +21,7 @@ import (
 	"code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/util"
 
-	"github.com/google/go-github/v39/github"
+	"github.com/google/go-github/v45/github"
 	"golang.org/x/oauth2"
 )
 
@@ -778,6 +778,7 @@ func (g *GithubDownloaderV3) GetReviews(reviewable base.Reviewable) ([]*base.Rev
 	opt := &github.ListOptions{
 		PerPage: g.maxPerPage,
 	}
+	// Get approve/request change reviews
 	for {
 		g.waitAndPickClient()
 		reviews, resp, err := g.getClient().PullRequests.ListReviews(g.ctx, g.repoOwner, g.repoName, int(reviewable.GetForeignIndex()), opt)
@@ -817,5 +818,28 @@ func (g *GithubDownloaderV3) GetReviews(reviewable base.Reviewable) ([]*base.Rev
 		}
 		opt.Page = resp.NextPage
 	}
+	// Get requested reviews
+	for {
+		g.waitAndPickClient()
+		reviewers, resp, err := g.getClient().PullRequests.ListReviewers(g.ctx, g.repoOwner, g.repoName, int(reviewable.GetForeignIndex()), opt)
+		if err != nil {
+			return nil, fmt.Errorf("error while listing repos: %v", err)
+		}
+		g.setRate(&resp.Rate)
+		for _, user := range reviewers.Users {
+			r := &base.Review{
+				ReviewerID:   user.GetID(),
+				ReviewerName: user.GetLogin(),
+				State:        base.ReviewStateRequestReview,
+				IssueIndex:   reviewable.GetLocalIndex(),
+			}
+			allReviews = append(allReviews, r)
+		}
+		// TODO: Handle Team requests
+		if resp.NextPage == 0 {
+			break
+		}
+		opt.Page = resp.NextPage
+	}
 	return allReviews, nil
 }