prefix of multibyte on grep-2.6.2

[Norihiro Tanaka]

Hi,

I have tested grep-2.6.2. However, I seem the fix for prefix of
multibyte is insufficient.

Please run following test case.

--
#!/bin/sh
# This would mistakenly print a line prior to grep-2.6.2.
: ${srcdir=.}
. "$srcdir/init.sh"; path_prepend_ ../src

encode() { echo "$1" | tr ABC '\357\274\241'; }

fail=0

for LOC in en_US.UTF-8 $LOCALE_FR_UTF8; do
  for opt in '' '-F'; do
    out=out-$opt-$LOC
    encode ABCABC | LC_ALL=$LOC grep $opt "$(encode ABCA)" > $out 2>&1
    test $? = 1 || fail=1
    compare $out /dev/null || fail=1
  done
done

Exit $fail
--

We will have to run is_mb_middle check up to end of matching string.