title: Git log only master branch
body: <h2>Is there any way to display in git log only commits, which have been ever pointed by master branch?</h2>
  
  <p><em>For example:</em></p>
  
  <pre><code>*   c7e0107 - (22 hours ago) Merge branch 'branch_b' - MASTER
  |\
  | *   3b90496 - (22 hours ago) Merge branch 'branch_a' into branch_b -
  | |\
  | * | 033fef1 - (22 hours ago) _____________ -
  | * | 29449c6 - (22 hours ago) _____________ - 
  * | |   cbd8a15 - (22 hours ago) Merge branch 'branch_a' - MASTER
  |\ \ \
  | | |/
  | |/|
  | * | e5e4aa4 - (22 hours ago) _____________ - 
  | * | 7215282 - (22 hours ago) _____________ - 
  | * | e9aadd9 - (22 hours ago) _____________ - 
  | * | 4824cef - (22 hours ago) _____________ - 
  * | | 4a13ff3 - (22 hours ago) _____________ - MASTER
  | |/
  |/|
  * | 77b9965 - (22 hours ago) _____________ - MASTER
  * | 47fef00 - (22 hours ago) _____________ - MASTER
  |/
  * 2cd1c2e - (22 hours ago) _____________ - MASTER
  * 768ebc8 - (22 hours ago) _____________ - MASTER
  </code></pre>
  
  <p>And I would like to display only commits described as 'MASTER'. I notice that '--first-parent' option or 'git cherry -v master' doesn't work. I can't also do it from graph because often master branch isn't on the leftmost side.</p>