Also find correct column width of wide characters.
Use unicodedata.east_asian_width() to determine wide/full width
characters if available. Otherwise, return character count as before.
#!/bin/sh
mkdir t
cd t
hg init
mkdir a
echo foo > a/a
echo bar > a/b
hg ci -Am "0" -d "0 0"
hg co -C 0
hg mv a b
hg ci -m "1 mv a/ b/" -d "0 0"
hg co -C 0
echo baz > a/c
echo quux > a/d
hg add a/c
hg ci -m "2 add a/c" -d "0 0"
hg merge --debug 1
echo a/* b/*
hg st -C
hg ci -m "3 merge 2+1" -d "0 0"
hg debugrename b/c
hg co -C 1
hg merge --debug 2
echo a/* b/*
hg st -C
hg ci -m "4 merge 1+2" -d "0 0"
hg debugrename b/c