From a1960e91a815b2cc9ac233579983eb9026b2409a Mon Sep 17 00:00:00 2001
From: Aaron Jacobs <jacobsa@google.com>
Date: Tue, 17 Mar 2015 12:45:06 +1100
Subject: [PATCH] Fixed a panic.

---
 samples/cachingfs/caching_fs_test.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/samples/cachingfs/caching_fs_test.go b/samples/cachingfs/caching_fs_test.go
index ee78f43..48e0e70 100644
--- a/samples/cachingfs/caching_fs_test.go
+++ b/samples/cachingfs/caching_fs_test.go
@@ -63,6 +63,11 @@ func (t *CachingFSTest) setUp(
 }
 
 func (t *CachingFSTest) TearDown() {
+	// Was the file system mounted?
+	if t.mfs == nil {
+		return
+	}
+
 	// Unmount the file system. Try again on "resource busy" errors.
 	delay := 10 * time.Millisecond
 	for {