message: Changed nil to NULL for C pointers
diff: mallocWithSize:([strings[i] lengthOfBytesUsingEncoding:NSUTF8StringEncoding] + 1) *
  sizeof(char)
  error:error];
  - if (!cStrings[i]) return nil;
  + if (!cStrings[i]) return NULL;
  strcpy(cStrings[i], strings[i].UTF8String);
  }
  