From 8cd41468c0ba5c4a8a7ca70b6c9141d6131db1c1 Mon Sep 17 00:00:00 2001
From: Tonis Tiigi <tonistiigi@gmail.com>
Date: Wed, 27 May 2020 14:58:16 -0700
Subject: [PATCH] cache: avoid nil dereference

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
---
 cache/refs.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/cache/refs.go b/cache/refs.go
index 91e41b142855..d932f4e96c04 100644
--- a/cache/refs.go
+++ b/cache/refs.go
@@ -180,7 +180,10 @@ func (cr *cacheRecord) Size(ctx context.Context) (int64, error) {
 		cr.mu.Unlock()
 		return usage.Size, nil
 	})
-	return s.(int64), err
+	if err != nil {
+		return 0, err
+	}
+	return s.(int64), nil
 }
 
 func (cr *cacheRecord) Parent() ImmutableRef {