As seen in https://mxr.mozilla.org/comm-central/search?string=nsISaveAsCharset , m-c has two callers of nsISaveAsCharset and c-c has one. The nsPrimitiveHelpers caller shouldn't exist anymore. The nsFormSubmission caller needs to exist, but nsISaveAsCharset is needlessly complicated and the needed functionality should be implemented as cleaner code without all the unneeded features. (Additionally, nsStandardURL should call the same code as nsFormSubmission, but currently does not.)

The most notable user of nsISaveAsCharset is Enigmail for https://www.mozdev.org/bugs/show_bug.cgi?id=14392 . It's unclear if that code is still needed in Enigmail. In any case, Enigmail catches the exception if nsISaveAsCharset instantiation fails, so things might be OK. The only other addon with a notable userbase seems to be https://addons.mozilla.org/en-US/firefox/addon/custom-buttons/ , which seems to use nsISaveAsCharset for plain conversion to UTF-8...

Things may have changed since and the only reference in c-c seems unused now.

Comment on attachment 8848780 [details] [diff] [review] patch for c-c [landed in comment #4] They forgot this in bug 1202401.

Comment on attachment 8848780 [details] [diff] [review] patch for c-c [landed in comment #4] https://hg.mozilla.org/comm-central/rev/3e7abcf349c2bf5498a985c7cdc4905f7c7c129b

Now no one uses nsISaveAsCharset & nsSaveAsCharset. We can just remove them.

Comment on attachment 8893674 [details] Bug 1202362 - Remove nsISaveAsCharset & nsSaveAsCharset. https://reviewboard.mozilla.org/r/164772/#review170168 Thank you!

Pushed by VYV03354@nifty.ne.jp: https://hg.mozilla.org/integration/autoland/rev/4b913ce6d827 Remove nsISaveAsCharset & nsSaveAsCharset. r=hsivonen

https://hg.mozilla.org/projects/date/rev/4b913ce6d82781f8680c720061d766cb80cda2e7 Bug 1202362 - Remove nsISaveAsCharset & nsSaveAsCharset. r=hsivonen