Comment 37 for bug 66015

User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.0.13) Gecko/2009080316 Ubuntu/8.10 (intrepid) Firefox/3.0.13
Build Identifier: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.0.13) Gecko/2009080316 Ubuntu/8.10 (intrepid) Firefox/3.0.13

It seems that the code for finding spelling dictionaries in inlineSpellCheckUI.js expects nonstandard dictionary names. On Linux, most spelling dictionaries have a file name like lc_RC where lc = language code (e.g. "en") and RC = region code (e.g. "US"), separated by an underscore. By contrast, Mozilla expects the separator to be a hyphen.

On a Fedora 12 alpha Live CD, when you install hunspell-en (the dictionary pack for English for hunspell) you get a language menu with unreadable computer-ish names like "en_GB" and "en_US". On Windows (and Debian, because they have a workaround in place), you get human-readable names like "English / United Kingdom" and "English / United States" in the spelling dictionary language menu.

Reproducible: Always

Steps to Reproduce:
1. Navigate to a page with a <textarea> or other spell-checkable element
2. Type in some typos
3. Right-click in the textarea, and inspect the Languages > submenu in the menu you got when you right-clicked
Actual Results:
 en_AU
 en_ZA
 en_GB
 en_US

Expected Results:
 English / Australia
 English / South Africa
 English / United Kingdom
 English / United States

https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/66015 is a related Ubuntu bug which has lots of triage notes (and also a fair amount of noise).

Note that Ubuntu inherited the Debian workaround, which has a problem (which is really the topic of the Ubuntu bug in question): it displays *both* the underscored names and the human-readable names.