The charsetalias.properties file is gone in Firefox 4? Most web sites in Hong Kong use the Big5-HKSCS charset but declare the charset as Big5. Without charsetalias.properties, the encoding needs to be manually changed very often when viewing them.

Question

I have been defining Big5 as an alias of Big5-HKSCS in charsetalias.properties. This makes Firefox renders pages declared as "Big5" to be rendered in Big5-HKSCS instead. Big5-HKSCS is a standard published by the Hong Kong government because the Big5 charset does not contain many common Chinese characters used in Hong Kong. However, Big5-HKSCS is just an extension of Big5, so most (if not all) Chinese web sites in Hong Kong using Big5-HKSCS declare their pages to be in Big5 in the <meta> tag.
I am now trying out Firefox 4 RC and found that the charsetalias.properties file is no longer there. So in order to read pages containing characters that are in Big5-HKSCS but not in Big5, I need to switch the encoding manually. This is extremely inconvenient. Can you consider bringing charsetalias.properties back?
[http://groups.google.com/group/mozilla.dev.i18n/browse_thread/thread/415caa98a6246a00 Someone noticed this issue as well.]

Answer 1

Here's the script I was working on.
It determines the encoding of the site by checking a couple of different ways the meta tag can supply encodings. One way is to have a charset attribute on a meta tag, and the other way is to have a meta tag with http-equiv="content-type" and have charset= be part of the content attribute.
(note: I think [https://developer.mozilla.org/en/DOM/document.characterSet document.characterSet()] might be a far more reliable way to detect encoding since it doesn't depend on the specific way the meta tag was written. But I haven't tested it.)
Debugging messages showed that it could detect the specified encodings fine on the few test pages I was trying it on. The problem is in the way I change the encoding.
It currently uses .setAttribute to attempt to modify the meta tags once it finds the encodings. Unfortunately, this doesn't change the selected encoding in Firefox. It doesn't affect the page source, either.
I have to replace those setAttribute calls with something that will actually affect the selected encoding in Firefox.... but I'm not sure what would accomplish that.
http://pastebin.com/Yt7fygXe
Just a little warning, it's case- and whitespace-sensitive because I didn't get around to using regular expressions yet. So if a page says charset="BIG5", you'll probably need to make it uppercase in the script as well. Sorry, I'm lazy!
Nonetheless, I ''hope'' this is a start...