title: Why don't I have to commit after git merge
body: <p>I have a repo master and I do with file1.txt and file2.txt</p>
  
  <pre><code>git checkout -b fix1
  </code></pre>
  
  <p>I then change file1.txt </p>
  
  <p>and I do a </p>
  
  <pre><code>git commit -a
  </code></pre>
  
  <p>then I do  a</p>
  
  <pre><code>git checkout master
  </code></pre>
  
  <p>then I do a </p>
  
  <pre><code>git checkout -b fix2
  </code></pre>
  
  <p>I then change file2.txt </p>
  
  <p>and I do a </p>
  
  <pre><code>git commit -a
  </code></pre>
  
  <p>then <code>git checkout master</code>
  then a </p>
  
  <pre><code>git merge fix1
  git marge fix2 
  </code></pre>
  
  <p>but if I do a</p>
  
  <pre><code> commit -a 
  </code></pre>
  
  <p>I get</p>
  
  <pre>
  # On branch master
  nothing to commit (working directory clean)
  </pre>