From 58c890f17ed6cadcd9cc47574e08587f0a3801cf Mon Sep 17 00:00:00 2001
From: Oliver Letterer <oliver.letterer@gmail.com>
Date: Wed, 8 May 2013 20:22:07 +0200
Subject: [PATCH] Adds missing [self.response
 respondsToSelector:@selector(allHeaderFields)] check.

---
 AFNetworking/AFHTTPRequestOperation.m | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/AFNetworking/AFHTTPRequestOperation.m b/AFNetworking/AFHTTPRequestOperation.m
index 80b61f8..4d9dd55 100644
--- a/AFNetworking/AFHTTPRequestOperation.m
+++ b/AFNetworking/AFHTTPRequestOperation.m
@@ -186,7 +186,7 @@ static void AFSwizzleClassMethodWithClassAndSelectorUsingBlock(Class klass, SEL
     }
 
     NSMutableURLRequest *mutableURLRequest = [self.request mutableCopy];
-    if ([[self.response allHeaderFields] valueForKey:@"ETag"]) {
+    if ([self.response respondsToSelector:@selector(allHeaderFields)] && [[self.response allHeaderFields] valueForKey:@"ETag"]) {
         [mutableURLRequest setValue:[[self.response allHeaderFields] valueForKey:@"ETag"] forHTTPHeaderField:@"If-Range"];
     }
     [mutableURLRequest setValue:[NSString stringWithFormat:@"bytes=%llu-", offset] forHTTPHeaderField:@"Range"];