title: HTACCESS Rewrite Underscores to Hyphens when file doesn't exist
body: <p>Ok so I've scoured other people's answered questions, but nothing seems to work?  What I want is to redirect all .html files containing underscores, to the same file name using hyphens UNLESS the underscored file exists.</p>
  
  <p>Here's my current .htaccess:</p>
  
  <pre><code>RewriteEngine On
  RewriteCond %{REQUEST_URI} ^(.*).html$
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteRule ^([^_]*)_([^_]*_.*) $1-$2 [N]
  RewriteRule ^([^_]*)_([^_]*)$ /testing/$1-$2 [L,R=302]
  </code></pre>
  
  <p>The result:
  1. When I navigate to /this_file_does_not_exist.html I am rewritten to /testing/this-file-does-not-exist.html</p>
  
  <ol start="2">
  <li>When I navigate to /this_file_does_exist.html I am still rewritten to /testing/this-file-does-exist.html</li>
  </ol>
  
  <p>Where am I going wrong?</p>