gecko-dev/layout/reftests/tab-size/tab-size-1.html

зеркало из https://github.com/mozilla/gecko-dev.git
<!-- this test will always insert a space -->
<pre style="-moz-tab-size: 1">A&#9;X</pre>
	`<!-- this test will always insert a space -->`
	`<pre style="-moz-tab-size: 1">A X</pre>`