repo: fix issue of fork repository no check the limit of users' repository (#5346)

models/repo.go

@@ -2348,6 +2348,10 @@ func HasForkedRepo(ownerID, repoID int64) (*Repository, bool, error) {
 
 // ForkRepository creates a fork of target repository under another user domain.
 func ForkRepository(doer, owner *User, baseRepo *Repository, name, desc string) (_ *Repository, err error) {
+	if !owner.CanCreateRepo() {
+		return nil, errors.ReachLimitOfRepo{owner.RepoCreationNum()}
+	}
+
 	repo := &Repository{
 		OwnerID:       owner.ID,
 		Owner:         owner,

routes/repo/pull.go

@@ -126,6 +126,8 @@ func ForkPost(c *context.Context, f form.CreateRepo) {
 	if err != nil {
 		c.Data["Err_RepoName"] = true
 		switch {
+		case errors.IsReachLimitOfRepo(err):
+			c.RenderWithErr(c.Tr("repo.form.reach_limit_of_creation", c.User.RepoCreationNum()), FORK, &f)
 		case models.IsErrRepoAlreadyExist(err):
 			c.RenderWithErr(c.Tr("repo.settings.new_owner_has_same_repo"), FORK, &f)
 		case models.IsErrNameReserved(err):