Fix DM -r

dm/DMJsonWriter.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "DMJsonWriter.h"
 
 #include "ProcStats.h"
@@ skipping 92 matching lines @@
     Json::Value root;
     const char* data = (const char*)json->data();
     if (!reader.parse(data, data+json->size(), root)) {
         return false;
     }
 
     const Json::Value& results = root["results"];
     BitmapResult br;
     for (unsigned i = 0; i < results.size(); i++) {
         const Json::Value& r = results[i];
-        br.name          = r["key"]["name"].asCString();
-        br.config        = r["key"]["config"].asCString();
-        br.sourceType    = r["key"]["source_type"].asCString();
-        br.sourceOptions = r["key"]["source_options"].asCString();
-        br.ext           = r["options"]["ext"].asCString();
-        br.md5           = r["md5"].asCString();
+        br.name       = r["key"]["name"].asCString();
+        br.config     = r["key"]["config"].asCString();
+        br.sourceType = r["key"]["source_type"].asCString();
+        br.ext        = r["options"]["ext"].asCString();
+        br.md5        = r["md5"].asCString();
+
+        if (!r["key"]["source_options"].isNull()) {
+            br.sourceOptions = r["key"]["source_options"].asCString();
+        }
         callback(br);
     }
     return true;
 }
 
 } // namespace DM