Is there any reason a poster would use single quotes embedded within double quotes (or vice versa), inside of a tag

The only reason to do that would be in a TITLE or ALT attribute,

TITLE="Commentary on 'Hush' by Joss"

which I can't see people using very much, or in JavaScript, where you need to do things like

onmouseover="alert('hello world')"

but we've specifically outlawed that by regex.

Oh, and if you're inline-stylesheeting you might want to do

style="font-family:'Times New Roman'"

for font names with spaces.

not just href

Didn't think of that. It's just unbroken attributes of all kinds isn't it? Though the link tag causes the worst problems.

EDIT: full HTML compatibilitycakes, in the example above, you shouldn't put quotes inside quotes, you should use the entity code for quotes, so you'd put

TITLE="Commentary on 'Hush' by Joss"

or

TITLE='Commentary on "Hush" by Joss'

and the use of double quotes is more correct for backward compatibility. I can't quote chapter and verse but some browsers only like double quotes.

I don't think link tags cause worse havoc than any other tag where mismatched quotes are concerned. In all cases, they cause a (potentially) large chunk of html to be ignored by the browser.

I'm no regex expert so I've no idea if this is doable, but is there a way to look inside every tag that takes parameters (like a href or font) and "close" every "open" single or double quote? It wouldn't be too different from what John H has already done with open tags, would it?

I don't think link tags cause worse havoc than any other tag where mismatched quotes are concerned.

I was thinking of that unable-to-edit, ita-had-to-get-under-the-hood thing. Has that been fixed?

That's the same havoc -- doesn't matter which tag broke it. The key difference is if you open with a ' or a " -- affects where it gets closed.

Jon's coded the fix. I haven't implemented it yet.

Yeah, I fixed that. That happened because the t form tags got caught inside the open quoted mess. I moved the tags to points further up and down the page. Probelem Sol-ved.

Jon's coded the fix. I haven't implemented it yet.

Speaking of which (and I don't mean to sound like I'm harassing you. Really), how's the implementation going for that all all the other mods?

I'm sifting them out one by one and looking at them that way, Jon. I want to make sure there's no cross-pollination of weirdness.

Not suggesting for a moment that we don't all write perfect code the first time, or anything.

And then I have to check they don't conflict with any of the changes I implemented in the meanwhile.

Not suggesting for a moment that we don't all write perfect code the first time, or anything.

Heh. I'd be shocked if you didn't find an error somewhere.

t off to see Harry Potter with my brother

I'm no regex expert so I've no idea if this is doable, but is there a way to look inside every tag that takes parameters (like a href or font) and "close" every "open" single or double quote?

I think that's heading toward a parser again.

How about this -- we grab the contents of every tag, and count the quotes in it. If it's not an even number, throw the error. Brute force again...

I like John's idea. We can require attribute authors to use the entity forms for quotes inside of attributes, if they want to use them in odd quantities.