title: EGit - more than 200 bases exception on merge
body: <p>I was trying to merge the master branch into another branch.</p>
  
  <p>I recieved the following wierd exception:</p>
  
  <pre><code>An internal error occurred during: "Merging with refs/heads/master".
  Exception caught during execution of merge command. org.eclipse.jgit.errors.NoMergeBaseException: No merge     base could be determined. Reason=CONFLICTS_DURING_MERGE_BASE_CALCULATION. "More than 200 merge bases for:
  a f66d2b5e393e04cea11e4b92a54e71bb6180cd5e
  b 8ca54ccc2c1df01813049f13d7ab88d0a7d28060 found:
  count 2"
  </code></pre>
  
  <p>Any ideas what this is?</p>
  
  <p>PS: Other branches do merge into master just fine.</p>