Last modified: 2012-08-23 19:04:12 UTC
There was a missing </small> in a users's signature in the [[Template talk:High-traffic]] page. The software (I'm guessing it's HTML tidy) correctly closed the missing tag, but then incorrectly reopened it on every block for several sections (starting at the "Comments" section). It only ended (in the "Category" section) after finding a matching <small>...</small> pair. It should not reopen a tag on the next block after closing it on a block's closing tag.
This is deliberate. The idea is that <small> This is lots of text. I expect it all to be small. </small> should work, so that HTML neophytes need not be troubled by block vs. inline tags (which is very unintuitive: why *shouldn't* you be able to declare multiple paragraphs emphasized all in one go?). It will occasionally have weird effects like this, and more subtle ones when it comes to CSS or JavaScript (because the nesting won't be as intended). Possibly we should disable it, if possible, but keep in mind that this will undoubtedly break a large number of pages.
I don't think changing it would affect many pages; every time I've seen where the intention was to change the size of text for more than one block element, it was done via CSS (often in a template). Even if it's the case, it would be better to explicitly do the closing/reopening in the parser, instead of letting tidy do the work, since with tidy there's a greater chance of it spilling (sometimes even into the interface).