title: Xcode 6.0.1 crashes when merging 2 branches
body: <p>Every time I try to merge a branch into another branch Xcode 6.0.1 crashes. </p>
  
  <p>So far I have:</p>
  
  <ol>
  <li><p>Tried from a different computer to merge the same branches (pushed them and pulled them before obviously) and it still crashes. </p></li>
  <li><p>Created a new branch from the "faulty branch" added a space in it and merged it back into the "faulty branch" with success. but couldn't merge it into the original branch i wanted to.</p></li>
  </ol>
  
  <p>Whats wrong with Xcode ? How can I merge the branches ? (there are about 100 files to merge)</p>
  
  <p><strong>EDIT 2</strong></p>
  
  <ol>
  <li><p>One of the files has a conflict, after resolving the conflict in the Xcode merge editor, it will crash not only when trying to merge but even when trying to look at on of the other files (looking at other files doesn't crash before resolving the conflict).</p></li>
  <li><p>editing one of the branches in such a way to avoid the conflict upon merging will save resolving the conflict, but Xcode will still crash when hitting merge</p></li>
  </ol>
  
  <p><strong>EDIT</strong> - adding the crash alert : </p>
  
  <pre><code>    Process:         Xcode [3146]
      Path:            /Applications/Xcode.app/Contents/MacOS/Xcode
      Identifier:      com.apple.dt.Xcode
      Version:         6.0.1 (6528)
      Build Info:      IDEFrameworks-6528000000000000~2
      App Item ID:     497799835
      App External ID: 712682811
      Code Type:       X86-64 (Native)
      Parent Process:  launchd [162]
      Responsible:     Xcode [3146]
      User ID:         501
  
      Date/Time:       2014-09-30 15:30:49.320 +0300
      OS Version:      Mac OS X 10.9.4 (13E28)
      Report Version:  11
      Anonymous UUID:  3A19C91F-0A10-76C9-10BB-C3B0EABB5390
  
  
      Crashed Thread:  0  Dispatch queue: com.apple.main-thread
  
      Exception Type:  EXC_CRASH (SIGABRT)
      Exception Codes: 0x0000000000000000, 0x0000000000000000
  
      Application Specific Information:
      Sending merge: to &lt;IDESourceControlMergeWindowController: 0x7fc4d0974a90&gt; from         &lt;NSButton: 0x7fc4cd57e7e0&gt;
      ProductBuildVersion: 6A317
      ASSERTION FAILURE in /SourceCache/IDEPlugins/IDEPlugins-                6244/IDEQuickLookEditor/Comparison/IDEQuickLookVersionsTwoUpSubmode.m:210
      Details:  primaryDocumentLocation should be an instance inheriting from         IDESourceControlDocumentLocation, but it is nil
      Object:   &lt;IDEQuickLookVersionsTwoUpSubmode: 0x7fc4d0e515d0&gt;
      Method:   -_saveMergeState
      Thread:   &lt;NSThread: 0x7fc4c9716f00&gt;{name = (null), num = 1}
      Hints:   
        0: Sending merge: to &lt;IDESourceControlMergeWindowController: 0x7fc4d0974a90&gt; from         &lt;NSButton: 0x7fc4cd57e7e0&gt;
      Backtrace:
        0  0x0000000106343f0a -[IDEAssertionHandler         handleFailureInMethod:object:fileName:lineNumber:assertionSignature:messageFormat:arguments:]         (in IDEKit)
        1  0x0000000105106baf _DVTAssertionHandler (in DVTFoundation)
        2  0x0000000105106e9e _DVTAssertionFailureHandler (in DVTFoundation)
        3  0x00000001150b4cee -[IDEQuickLookVersionsTwoUpSubmode _saveMergeState] (in         IDEQuickLookEditor)
        4  0x00000001065f69f4 -[IDESourceControlConflictResolutionController         completeConflictResolution] (in IDEKit)
        5  0x000000010646d4f4 -[IDESourceControlMergeWindowController merge:] (in IDEKit)
        6  0x00007fff85a2b260 -[NSApplication sendAction:to:from:] (in AppKit)
        7  0x000000010566d200 __37-[DVTApplication sendAction:to:from:]_block_invoke (in         DVTKit)
        8  0x0000000105107ec2 DVTInvokeWithFailureHint (in DVTFoundation)
        9  0x000000010553777e -[DVTApplication sendAction:to:from:] (in DVTKit)
       10  0x00007fff85a2b0de -[NSControl sendAction:to:] (in AppKit)
       11  0x00007fff85a77c4d -[NSCell _sendActionFrom:] (in AppKit)
       12  0x00007fff85a91655 -[NSCell trackMouse:inRect:ofView:untilMouseUp:] (in AppKit)
       13  0x00007fff85a90a27 -[NSButtonCell trackMouse:inRect:ofView:untilMouseUp:] (in AppKit)
       14  0x00007fff85a9013d -[NSControl mouseDown:] (in AppKit)
       15  0x00007fff85a11a58 -[NSWindow sendEvent:] (in AppKit)
       16  0x00007fff859b05d4 -[NSApplication sendEvent:] (in AppKit)
       17  0x000000010610fc74 -[IDEApplication sendEvent:] (in IDEKit)
       18  0x00007fff858009f9 -[NSApplication run] (in AppKit)
       19  0x00007fff857eb783 NSApplicationMain (in AppKit)
       20  0x00007fff8e89d5fd start (in libdyld.dylib)
  
      Performing @selector(merge:) from sender NSButton 0x7fc4cd57e7e0
      abort() called
  
      Application Specific Signatures:
      (primaryDocumentLocation) != nil
  </code></pre>