title: how can I customize git's merge commit message?
body: <p>Every time I do a merge I need for a merge commit to be generated and I would like it to have more than just the summary of all the commits.</p>
  
  <p><strong>My question is how can I format git-fmt-merge-msg or what determines this automated message</strong> (I can do this manually after a commit by amending it and using git-log --pretty=format:'...')</p>
  
  <p>For example I would like to format it as such:</p>
  
  <pre><code> Merge branch 'test'  
      * test:  
        [BZ: #123] fifth commit subject  
        [BZ: #123] fourth commit subject  
        [BZ: #123] third commit subject  
        [BZ: #123] second commit subject  
        [BZ: #123] first commit subject  
  
   __________________________________________
   Merge details:  
       [BZ: #123] fifth commit subject  
                 at 2010-06-30 11:29:00 +0100  
         - fifth commit body  
  
       [BZ: #123] fourth commit subject  
                 at 2010-06-30 11:22:17 +0100  
         - fourth commit body  
  
       [BZ: #123] third commit subject  
                 at 2010-06-30 11:21:43 +0100  
         - third commit body  
  
       [BZ: #123] second commit subject  
                 at 2010-06-30 11:21:30 +0100  
         - second commit body  
  
       [BZ: #123] first commit subject  
                 at 2010-06-30 11:29:57 +0100  
         - first commit body
  </code></pre>