On the main page of StackExchange sites, hovering over any question link produces a quick preview of the body of the question, which is a very nice feature. However, newlines in the body are reproduced as newlines in the hover-text source. This causes Firefox 3.6 to silently drop the newlines, mashing together text from different paragraphs in jarring, poorly-punctuated fashion (e.g. "… by clicking DraftsI'd like to see …", or "…deleted their own question?I provided an answer…"). It would be nice if the backend could replaced newlines with spaces instead.
You're taking that part of the spec out of context. Here it is in full:
In certain cases, authors may specify the value of an attribute without any quotation marks. The attribute value may only contain letters (a-z and A-Z), digits (0-9), hyphens (ASCII decimal 45), periods (ASCII decimal 46), underscores (ASCII decimal 95), and colons (ASCII decimal 58). We recommend using quotation marks even when it is possible to eliminate them.
In other words, you're limited to that small set of characters (which, you should note, does not include spaces) iff you don't put the attribute in quotes.
CDATA is a sequence of characters from the document character set and may include character entities. User agents should interpret attribute values as follows:
- Replace character entities with characters,
- Ignore line feeds,
- Replace each carriage return or tab with a single space.
Given that, it's clear that line feeds, carriage returns, and tabs are valid characters.
What it appears you'd like is for SO to change their line feeds (per the spec, ignored by FF) to carriage returns (per the spec, converted into spaces). Is that correct?