On one MSE question, the comments are overlapping the related questions sidebar. Is this something to do with the weird formatting of the first comment?
Mozilla/5.0 (Windows NT 6.0; rv:16.0) Gecko/20100101 Firefox/16.0
Well, since comments won't allow the ordinary
This results in one long stream of characters without any blank space, no different than:
Each browser handles such things in its own way; I don't think there's much to be done.
Just in case, here is the culprit string of characters:
If you run the above through an ASCII converter (this one was built from scratch just now, as I didn't find any decent converter online) you will see there is no blank space but rather a character with ASCII value 822 following each letter.
This is a pretty common display bug that can be triggered in many ways: silly Unicode tricks, long code blocks, broken MathJax, missing MathJax delimiters, changing the font size in Chrome or in Firefox, etc. It was first reported a long time ago, and a server-side kluge was added to "fix" it (occasionally breaking code embedded in comments or very long URLs as a side effect), but it didn't really solve the problem completely.
The common thread in all these bug reports is that they involve some kind of an over-wide unbreakable block of text in a comment, which causes the table that contains the comments to extend to accommodate it, overflowing out of the main content area and into the sidebar.
There's a simple CSS fix that (mostly) solves this bug: just set an explicit
This will cause any over-wide comments to stay within their prescribed bounds, breaking long words if necessary, and acquiring a horizontal scroll bar if even that doesn't help, like this:
Ps. This fix is include in the latest version (v1.22) of the Stack Overflow Unofficial Patch user script. (Earlier versions had a slightly different fix, which used