Chrome Version       : 56.0.2914.3
OS Version: Ubuntu 14.04/macOS 10.12
URLs (if applicable) : https://jsbin.com/wodaxiloge/1/edit?html,output
Other browsers tested:
  Add OK or FAIL after other browsers where you have tested this issue:
     Safari 5:
  Firefox 4.x: OK
     IE 7/8/9:

What steps will reproduce the problem?
1. Open JSbin link above
2. Click in the output pane to focus it, then press tab to focus the link
3. Observe that the link has a focus outline around it
4. Uncomment the CSS line for `outline: auto`
5. Repeat steps 2 and 3

What is the expected result?

The focus outline should be the same as in step 3

What happens instead of that?

The focus outline is cropped down significantly. This is particularly noticeable on macOS, which has larger focus outlines than Windows/Linux.

Please provide any additional information below. Attach a screenshot if
possible.

UserAgentString: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2914.3 Safari/537.36

This is an issue in MD History ( issue 655503 ), but we have a workaround available.