ui: add special-purpose atexit functionality
In spite of its longstanding use, Python's built-in atexit code is
not suitable for Mercurial's purposes, for several reasons:
* Handlers run after application code has finished.
* Because of this, the code that runs handlers swallows exceptions
(since there's no possible stacktrace to associate errors with).
If we're lucky, we'll get something spat out to stderr (if stderr
still works), which of course isn't any use in a big deployment
where it's important that exceptions get logged and aggregated.
* Mercurial's current atexit handlers make unfortunate assumptions
about process state (specifically stdio) that, coupled with the
above problems, make it impossible to deal with certain categories
of error (try "hg status > /dev/full" on a Linux box).
* In Python 3, the atexit implementation is completely hidden, so
we can't hijack the platform's atexit code to run handlers at a
time of our choosing.
As a result, here's a perfectly cromulent atexit-like implementation
over which we have control. This lets us decide exactly when the
handlers run (after each request has completed), and control what
the process state is when that occurs (and afterwards).
Test text wrapping for multibyte characters
$ mkdir t
$ cd t
define commands to display help text
$ cat << EOF > show.py
> from mercurial import cmdutil
>
> cmdtable = {}
> command = cmdutil.command(cmdtable)
>
> # Japanese full-width characters:
> @command('show_full_ja', [], '')
> def show_full_ja(ui, **opts):
> u'''\u3042\u3044\u3046\u3048\u304a\u304b\u304d\u304f\u3051 \u3042\u3044\u3046\u3048\u304a\u304b\u304d\u304f\u3051 \u3042\u3044\u3046\u3048\u304a\u304b\u304d\u304f\u3051
>
> \u3042\u3044\u3046\u3048\u304a\u304b\u304d\u304f\u3051 \u3042\u3044\u3046\u3048\u304a\u304b\u304d\u304f\u3051 \u3042\u3044\u3046\u3048\u304a\u304b\u304d\u304f\u3051 \u3042\u3044\u3046\u3048\u304a\u304b\u304d\u304f\u3051
>
> \u3042\u3044\u3046\u3048\u304a\u304b\u304d\u304f\u3051\u3042\u3044\u3046\u3048\u304a\u304b\u304d\u304f\u3051\u3042\u3044\u3046\u3048\u304a\u304b\u304d\u304f\u3051\u3042\u3044\u3046\u3048\u304a\u304b\u304d\u304f\u3051
> '''
>
> # Japanese half-width characters:
> @command('show_half_ja', [], '')
> def show_half_ja(ui, *opts):
> u'''\uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79 \uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79 \uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79 \uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79
>
> \uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79 \uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79 \uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79 \uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79 \uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79 \uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79 \uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79 \uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79
>
> \uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79\uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79\uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79\uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79\uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79\uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79\uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79\uff71\uff72\uff73\uff74\uff75\uff76\uff77\uff78\uff79
> '''
>
> # Japanese ambiguous-width characters:
> @command('show_ambig_ja', [], '')
> def show_ambig_ja(ui, **opts):
> u'''\u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb \u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb \u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb
>
> \u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb \u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb \u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb \u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb \u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb \u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb \u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb
>
> \u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb\u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb\u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb\u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb\u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb\u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb\u03b1\u03b2\u03b3\u03b4\u03c5\u03b6\u03b7\u03b8\u25cb
> '''
>
> # Russian ambiguous-width characters:
> @command('show_ambig_ru', [], '')
> def show_ambig_ru(ui, **opts):
> u'''\u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438 \u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438 \u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438 \u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438 \u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438
>
> \u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438 \u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438 \u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438 \u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438 \u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438 \u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438
>
> \u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438\u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438\u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438\u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438\u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438\u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438\u041d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0438
> '''
> EOF
"COLUMNS=60" means that there is no lines which has grater than 58 width
(1) test text wrapping for non-ambiguous-width characters
(1-1) display Japanese full-width characters in cp932
$ COLUMNS=60 hg --encoding cp932 --config extensions.show=./show.py help show_full_ja
hg show_full_ja
\x82\xa0\x82\xa2\x82\xa4\x82\xa6\x82\xa8\x82\xa9\x82\xab\x82\xad\x82\xaf \x82\xa0\x82\xa2\x82\xa4\x82\xa6\x82\xa8\x82\xa9\x82\xab\x82\xad\x82\xaf \x82\xa0\x82\xa2\x82\xa4\x82\xa6\x82\xa8\x82\xa9\x82\xab\x82\xad\x82\xaf (esc)
\x82\xa0\x82\xa2\x82\xa4\x82\xa6\x82\xa8\x82\xa9\x82\xab\x82\xad\x82\xaf \x82\xa0\x82\xa2\x82\xa4\x82\xa6\x82\xa8\x82\xa9\x82\xab\x82\xad\x82\xaf (esc)
\x82\xa0\x82\xa2\x82\xa4\x82\xa6\x82\xa8\x82\xa9\x82\xab\x82\xad\x82\xaf \x82\xa0\x82\xa2\x82\xa4\x82\xa6\x82\xa8\x82\xa9\x82\xab\x82\xad\x82\xaf (esc)
\x82\xa0\x82\xa2\x82\xa4\x82\xa6\x82\xa8\x82\xa9\x82\xab\x82\xad\x82\xaf\x82\xa0\x82\xa2\x82\xa4\x82\xa6\x82\xa8\x82\xa9\x82\xab\x82\xad\x82\xaf\x82\xa0\x82\xa2\x82\xa4\x82\xa6\x82\xa8\x82\xa9\x82\xab\x82\xad\x82\xaf (esc)
\x82\xa0\x82\xa2\x82\xa4\x82\xa6\x82\xa8\x82\xa9\x82\xab\x82\xad\x82\xaf (esc)
(some details hidden, use --verbose to show complete help)
(1-2) display Japanese full-width characters in utf-8
$ COLUMNS=60 hg --encoding utf-8 --config extensions.show=./show.py help show_full_ja
hg show_full_ja
\xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a\xe3\x81\x8b\xe3\x81\x8d\xe3\x81\x8f\xe3\x81\x91 \xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a\xe3\x81\x8b\xe3\x81\x8d\xe3\x81\x8f\xe3\x81\x91 \xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a\xe3\x81\x8b\xe3\x81\x8d\xe3\x81\x8f\xe3\x81\x91 (esc)
\xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a\xe3\x81\x8b\xe3\x81\x8d\xe3\x81\x8f\xe3\x81\x91 \xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a\xe3\x81\x8b\xe3\x81\x8d\xe3\x81\x8f\xe3\x81\x91 (esc)
\xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a\xe3\x81\x8b\xe3\x81\x8d\xe3\x81\x8f\xe3\x81\x91 \xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a\xe3\x81\x8b\xe3\x81\x8d\xe3\x81\x8f\xe3\x81\x91 (esc)
\xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a\xe3\x81\x8b\xe3\x81\x8d\xe3\x81\x8f\xe3\x81\x91\xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a\xe3\x81\x8b\xe3\x81\x8d\xe3\x81\x8f\xe3\x81\x91\xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a\xe3\x81\x8b\xe3\x81\x8d\xe3\x81\x8f\xe3\x81\x91 (esc)
\xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a\xe3\x81\x8b\xe3\x81\x8d\xe3\x81\x8f\xe3\x81\x91 (esc)
(some details hidden, use --verbose to show complete help)
(1-3) display Japanese half-width characters in cp932
$ COLUMNS=60 hg --encoding cp932 --config extensions.show=./show.py help show_half_ja
hg show_half_ja
\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 \xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 \xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 \xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 (esc)
\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 \xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 \xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 \xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 \xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 (esc)
\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 \xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 \xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 (esc)
\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 (esc)
\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9 (esc)
(some details hidden, use --verbose to show complete help)
(1-4) display Japanese half-width characters in utf-8
$ COLUMNS=60 hg --encoding utf-8 --config extensions.show=./show.py help show_half_ja
hg show_half_ja
\xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 \xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 \xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 \xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 (esc)
\xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 \xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 \xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 \xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 \xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 (esc)
\xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 \xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 \xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 (esc)
\xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9\xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9\xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9\xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9\xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9\xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 (esc)
\xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9\xef\xbd\xb1\xef\xbd\xb2\xef\xbd\xb3\xef\xbd\xb4\xef\xbd\xb5\xef\xbd\xb6\xef\xbd\xb7\xef\xbd\xb8\xef\xbd\xb9 (esc)
(some details hidden, use --verbose to show complete help)
(2) test text wrapping for ambiguous-width characters
(2-1) treat width of ambiguous characters as narrow (default)
(2-1-1) display Japanese ambiguous-width characters in cp932
$ COLUMNS=60 hg --encoding cp932 --config extensions.show=./show.py help show_ambig_ja
hg show_ambig_ja
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b \x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b \x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b \x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b \x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b \x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b \x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b \x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
(some details hidden, use --verbose to show complete help)
(2-1-2) display Japanese ambiguous-width characters in utf-8
$ COLUMNS=60 hg --encoding utf-8 --config extensions.show=./show.py help show_ambig_ja
hg show_ambig_ja
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b \xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b \xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b \xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b \xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b \xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b \xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b \xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
(some details hidden, use --verbose to show complete help)
(2-1-3) display Russian ambiguous-width characters in cp1251
$ COLUMNS=60 hg --encoding cp1251 --config extensions.show=./show.py help show_ambig_ru
hg show_ambig_ru
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
(some details hidden, use --verbose to show complete help)
(2-1-4) display Russian ambiguous-width characters in utf-8
$ COLUMNS=60 hg --encoding utf-8 --config extensions.show=./show.py help show_ambig_ru
hg show_ambig_ru
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
(some details hidden, use --verbose to show complete help)
(2-2) treat width of ambiguous characters as wide
(2-2-1) display Japanese ambiguous-width characters in cp932
$ COLUMNS=60 HGENCODINGAMBIGUOUS=wide hg --encoding cp932 --config extensions.show=./show.py help show_ambig_ja
hg show_ambig_ja
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b \x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b \x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b \x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b \x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b \x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
\x83\xbf\x83\xc0\x83\xc1\x83\xc2\x83\xd2\x83\xc4\x83\xc5\x83\xc6\x81\x9b (esc)
(some details hidden, use --verbose to show complete help)
(2-2-2) display Japanese ambiguous-width characters in utf-8
$ COLUMNS=60 HGENCODINGAMBIGUOUS=wide hg --encoding utf-8 --config extensions.show=./show.py help show_ambig_ja
hg show_ambig_ja
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b \xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b \xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b \xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b \xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b \xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
\xce\xb1\xce\xb2\xce\xb3\xce\xb4\xcf\x85\xce\xb6\xce\xb7\xce\xb8\xe2\x97\x8b (esc)
(some details hidden, use --verbose to show complete help)
(2-2-3) display Russian ambiguous-width characters in cp1251
$ COLUMNS=60 HGENCODINGAMBIGUOUS=wide hg --encoding cp1251 --config extensions.show=./show.py help show_ambig_ru
hg show_ambig_ru
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 \xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
\xcd\xe0\xf1\xf2\xf0\xee\xe9\xea\xe8 (esc)
(some details hidden, use --verbose to show complete help)
(2-2-4) display Russian ambiguous-width characters in utf-8
$ COLUMNS=60 HGENCODINGAMBIGUOUS=wide hg --encoding utf-8 --config extensions.show=./show.py help show_ambig_ru
hg show_ambig_ru
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 \xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
\xd0\x9d\xd0\xb0\xd1\x81\xd1\x82\xd1\x80\xd0\xbe\xd0\xb9\xd0\xba\xd0\xb8 (esc)
(some details hidden, use --verbose to show complete help)
$ cd ..