Fixes a crash for resumed images with long keys (#383)

* Fixes a crash for resumed images with long keys

Keys that are long would get their key hashed. This meant that when en/decoding
the object, it wouldn't be recognized as an object that needed to be un/archived.

* Add changelog entry

CHANGELOG.md

@@ -3,6 +3,7 @@
 - [fixed] Fixes a deadlock with canceling processor tasks [#374](https://github.com/pinterest/PINRemoteImage/pull/374) [zachwaugh](https://github.com/zachwaugh)
 - [fixed] Fixes a deadlock in the retry system. [garrettmoon](https://github.com/garrettmoon)
 - [fixed] Fixes a threadsafety issue in accessing callbacks. [garrettmoon](https://github.com/garrettmoon)
+- [fixed] Fixes a crash with resumed downloads when a key is long. [garrettmoon](https://github.com/garrettmoon)
 - [new] PINRemoteImageManager now respects the request timeout value of session configuration. [garrettmoon](https://github.com/garrettmoon)
 - [new] Updated to latest PINCache beta 5. [garrettmoon](https://github.com/garrettmoon)
 - [new] Added support for getting NSURLResponse from a PINRemoteImageManagerResult object. [garrettmoon](https://github.com/garrettmoon)

Source/Classes/PINRemoteImageManager.m

@@ -1517,9 +1517,6 @@ - (NSString *)cacheKeyForURL:(NSURL *)url processorKey:(NSString *)processorKey
     if (processorKey.length > 0) {
         cacheKey = [cacheKey stringByAppendingFormat:@"-<%@>", processorKey];
     }
-    if (resume) {
-        cacheKey = [PINRemoteImageCacheKeyResumePrefix stringByAppendingString:cacheKey];
-    }
 
     //PINDiskCache uses this key as the filename of the file written to disk
     //Due to the current filesystem used in Darwin, this name must be limited to 255 chars.
@@ -1542,6 +1539,10 @@ - (NSString *)cacheKeyForURL:(NSURL *)url processorKey:(NSString *)processorKey
         }
         cacheKey = [hexString copy];
     }
+    //The resume key must not be hashed, it is used to decide whether or not to decode from the disk cache.
+    if (resume) {
+      cacheKey = [PINRemoteImageCacheKeyResumePrefix stringByAppendingString:cacheKey];
+    }
 
     return cacheKey;
 }