title: writeToFile atomically returns NO
body: <p>I have the following code:</p>
  
  <pre><code>NSString *errorStr = nil;
  NSData *plistData = [NSPropertyListSerialization dataFromPropertyList:dict
                                                                 format:NSPropertyListBinaryFormat_v1_0
                                                       errorDescription:&amp;errorStr];
  if (errorStr) {
      // Darn.
      NSLog(@"saving dictionary error %@", errorStr);
  } else {
      // [plistData writeToFile:file atomically:YES];
      // (ankit): Changing this to NO for speed.
      success = [plistData writeToFile:file atomically:NO];
  }
  </code></pre>
  
  <p>however this returns NO, for the following dictionary:</p>
  
  <pre><code>  {
      entries = (
                  {
              author = "Jada Wong";
              cellIdentifier = default;
              date = "2012-10-15 02:22:41 +0000";
              domain = Readability;
              feedUrl = "readability://feed";
              imagesAreOnPulsesubscriber = 0;
              order = 0;
              summary = "";
              templateUrl = "default_template.html";
              title = "We\U2019re Going To Try Out Dolce &amp; Gabbana\U2019s Beauty Look This Weekend";
              url = "http://www.styleite.com/media/styledish-10122012/";
          }
      );
  }
  </code></pre>
  
  <p>but it works for the following dict:</p>
  
  <pre><code>{
      entries =     (
                  {
              author = "Colleen Taylor";
              cellIdentifier = default;
              date = "2012-10-15 01:00:05 +0000";
              domain = TechCrunch;
              domainUrl = "http://techcrunch.com";
              feedUrl = "http:/asdasdm/TechCrunch";
              images =             (
                  "http://asdshot-2012-10-14-at-5-20-43-pm.png"
              );
              imagesAreOnPulsesubscriber = 1;
              lastUpdated = 1350263095;
              order = 0;
              shortLink = "http://bete.me/s/ej2Tg";
              summary = "Bonobos, the men's clothing company, has gained lots of ground since it was founded in 2007 for its presence on the web as a mostly pure e-commerce p...";
              templateUrl = "default_template.html";
              title = "Inside Bonobos\U2019 New Palo Alto Digs, Where The Startup Known For E-Commerce Is Investing In Bricks &amp; Mortar";
              url = "http://techcrunch.com/2012/10/14/bonobos-palo-alto-mike-hart/";
          }
      );
  }
  </code></pre>
  
  <p>Any idea why? It worked for different dictionary 
  The file path I am writing to is:</p>
  
  <pre><code>/var/mobile/Applications/4B60A704-BE00-4160-BFB4-AD89187FADD1/Library/Caches/StoryCache/readability:  feed
  </code></pre>
  
  <p>The error I got is:</p>
  
  <pre><code>"The operation couldn\u2019t be completed. (Cocoa error 512.)" UserInfo=0xb41580 {NSFilePath=/var/mobile/Applications/4B60A704-BE00-4160-BFB4-AD89187FADD1/Library/Caches/StoryCache/readability:  feed, NSUnderlyingError=0xbb8930 "The operation couldn\u2019t be completed. Is a directory"}
  </code></pre>