From ac9c20b04848ececf3fee156dc181bc27e01dd80 Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Sat, 14 May 2016 17:11:19 +0100
Subject: [PATCH] Make IsRetryError function

---
 fs/error.go      | 9 +++++++++
 fs/operations.go | 2 +-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/fs/error.go b/fs/error.go
index 66d32af18..97c9e2ee3 100644
--- a/fs/error.go
+++ b/fs/error.go
@@ -58,6 +58,15 @@ func RetryError(err error) error {
 	return plainRetryError{err}
 }
 
+// IsRetryError returns true if err conforms to the Retry interface
+// and calling the Retry method returns true.
+func IsRetryError(err error) bool {
+	if r, ok := err.(Retry); ok {
+		return r.Retry()
+	}
+	return false
+}
+
 // isClosedConnError reports whether err is an error from use of a closed
 // network connection.
 //
diff --git a/fs/operations.go b/fs/operations.go
index 8c9568766..6c4201204 100644
--- a/fs/operations.go
+++ b/fs/operations.go
@@ -238,7 +238,7 @@ tryAgain:
 		inErr = in.Close()
 	}
 	// Retry if err returned a retry error
-	if r, ok := err.(Retry); ok && r.Retry() && tries < maxTries {
+	if IsRetryError(err) && tries < maxTries {
 		tries++
 		Log(src, "Received error: %v - low level retry %d/%d", err, tries, maxTries)
 		if removeFailedCopy(dst) {