Don't list root repository on compare page if pulls not allowed (#24183)

Fix #24165

Author: lunny

routers/web/repo/compare.go

@@ -459,7 +459,7 @@ func ParseCompareInfo(ctx *context.Context) *CompareInfo {
 		rootRepo.ID != ci.HeadRepo.ID &&
 		rootRepo.ID != baseRepo.ID {
 		canRead := access_model.CheckRepoUnitUser(ctx, rootRepo, ctx.Doer, unit.TypeCode)
-		if canRead {
+		if canRead && rootRepo.AllowsPulls() {
 			ctx.Data["RootRepo"] = rootRepo
 			if !fileOnly {
 				branches, tags, err := getBranchesAndTagsForRepo(ctx, rootRepo)