view tests/test-encoding-textwrap.t @ 49000:dd6b67d5c256 stable

rust: fix unsound `OwningDirstateMap`

As per the previous patch, `OwningDirstateMap` is unsound. Self-referential
structs are difficult to implement correctly in Rust since the compiler is
free to move structs around as much as it wants to. They are also very rarely
needed in practice, so the state-of-the-art on how they should be done within
the Rust rules is still a bit new.

The crate `ouroboros` is an attempt at providing a safe way (in the Rust sense)
of declaring self-referential structs. It is getting a lot attention and was
improved very quickly when soundness issues were found in the past: rather than
relying on our own (limited) review circle, we might as well use the de-facto
common crate to fix this problem. This will give us a much better chance of
finding issues should any new ones be discovered as well as the benefit of
fewer `unsafe` APIs of our own.

I was starting to think about how I would present a safe API to the old struct
but soon realized that the callback-based approach was already done in
`ouroboros`, along with a lot more care towards refusing incorrect structs.

In short: we don't return a mutable reference to the `DirstateMap` anymore, we
expect users of its API to pass a `FnOnce` that takes the map as an argument.
This allows our `OwningDirstateMap` to control the input and output lifetimes
of the code that modifies it to prevent such issues.

Changing to `ouroboros` meant changing every API with it, but it is relatively
low churn in the end. It correctly identified the example buggy modification of
`copy_map_insert` outlined in the previous patch as violating the borrow rules.

Differential Revision: https://phab.mercurial-scm.org/D12429

Test text wrapping for multibyte characters

  $ mkdir t
  $ cd t

define commands to display help text

  $ cat << EOF > show.py
  > from mercurial import registrar
  > 
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > 
  > # Japanese full-width characters:
  > @command(b'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(b'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(b'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(b'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 ..