Fix forking an empty repository (#6637)

Fixes #6633

Signed-off-by: Segev Finer <segev@codeocean.com>

models/repo.go

 		Description:   desc,
 		DefaultBranch: oldRepo.DefaultBranch,
 		IsPrivate:     oldRepo.IsPrivate,
+		IsEmpty:       oldRepo.IsEmpty,
 		IsFork:        true,
 		ForkID:        oldRepo.ID,
 	}

modules/context/repo.go

 			ctx.Data["IsStaringRepo"] = models.IsStaring(ctx.User.ID, repo.ID)
 		}
 
+		if repo.IsFork {
+			RetrieveBaseRepo(ctx, repo)
+			if ctx.Written() {
+				return
+			}
+		}
+
 		// repo is empty and display enable
 		if ctx.Repo.Repository.IsEmpty {
 			ctx.Data["BranchName"] = ctx.Repo.Repository.DefaultBranch
 		ctx.Data["BranchName"] = ctx.Repo.BranchName
 		ctx.Data["CommitID"] = ctx.Repo.CommitID
 
-		if repo.IsFork {
-			RetrieveBaseRepo(ctx, repo)
-			if ctx.Written() {
-				return
-			}
-		}
-
 		// People who have push access or have forked repository can propose a new pull request.
 		if ctx.Repo.CanWrite(models.UnitTypeCode) || (ctx.IsSigned && ctx.User.HasForkedRepo(ctx.Repo.Repository.ID)) {
 			// Pull request is allowed if this is a fork repository