1069954 - Remove us-ascii as a Gecko-canonical encoding

Status: RESOLVED FIXED

(Core :: Internationalization, defect)

Description

[Henri Sivonen (:hsivonen)]

For the Web, us-ascii is already an alias of windows-1252.

Our us-ascii encoding already decodes like windows-1252. It encodes differently, but we don't seem to have in-tree dependencies on that. The addons MXR is broken, though, so I can't search addons.

Comment 1

[Henri Sivonen (:hsivonen)]

Attachment: Remove the encoding

https://tbpl.mozilla.org/?tree=Try&rev=3d071d57972a

Comment 2

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Would this affect, say, what content Thunderbird considers reasonable to label as us-ascii when sending email?

Comment 3

[Henri Sivonen (:hsivonen)]

(In reply to David Baron [:dbaron] (UTC-7) (needinfo? for questions) from comment #2)
> Would this affect, say, what content Thunderbird considers reasonable to
> label as us-ascii when sending email?

Most likely not.

Longer answer:

Thunderbird, by default, avoids labeling anything as us-ascii thanks to bug 247958. Unfortunately, the pref the change this behavior is still around.

us-ascii is not the default outgoing encodoing in any Thunderbird locale, and bug 1003716 is in the process of removing UI for setting the default to us-ascii.

Per bug 999881 comment 5, Thunderbird is now not supposed to, even when replying, send email using an encoding that's not in the compose encoding menu.

In various places, there's logic similar to https://mxr.mozilla.org/comm-central/source/mail/components/compose/content/MsgComposeCommands.js#2451 : if US-ASCII, use ISO-8859-1 instead.

Converting various things is optimized not to use our normal encodings for us-ascii and ISO-8859-1:
https://mxr.mozilla.org/comm-central/source/mailnews/base/util/nsMsgI18N.cpp#44

When encoding a messages, the ASCIIness check uses NS_IsAscii instead of relying the encoder returning an error:
https://mxr.mozilla.org/comm-central/source/mailnews/base/util/nsMsgI18N.cpp#366

That said, as with other removals of stuff under intl/ that's dead code in Firefox, Thunderbird developers have the option of importing us-ascii as a Gecko-canonical encoding into c-c.

(In reply to Henri Sivonen (:hsivonen) from comment #0)
> The addons MXR is broken, though, so I can't search addons.

It looks like add-ons are unaffected.

Comment 4

[Henri Sivonen (:hsivonen)]

Thanks. Landed:
https://hg.mozilla.org/integration/mozilla-inbound/rev/90bfac52d494

Comment 5

[Henri Sivonen (:hsivonen)]

This has been merged:
https://hg.mozilla.org/mozilla-central/rev/90bfac52d494