replace Python standard textwrap by MBCS sensitive one for i18n text...
replace Python standard textwrap by MBCS sensitive one for i18n text
Mercurial has problem around text wrapping/filling in MBCS encoding
environment, because standard 'textwrap' module of Python can not
treat it correctly. It splits byte sequence for one character into two
lines.
According to unicode specification, "east asian width" classifies
characters into:
W(ide), N(arrow), F(ull-width), H(alf-width), A(mbiguous)
W/N/F/H can be always recognized as 2/1/2/1 bytes in byte sequence,
but 'A' can not. Size of 'A' depends on language in which it is used.
Unicode specification says:
If the context(= language) cannot be established reliably they
should be treated as narrow characters by default
but many of class 'A' characters are full-width, at least, in Japanese
environment.
So, this patch treats class 'A' characters as full-width always for
safety wrapping.
This patch focuses only on MBCS safe-ness, not on writing/printing
rule strict wrapping for each languages
MBCS sensitive textwrap class is originally implemented
by ITO Nobuaki <daydream.trippers@gmail.com>.
