bug#23752: [PATCH] grep: try fgrep matcher for case insensitive matching by grep -F in multibyte locale

[Paul Eggert]

Thanks for that performance improvement. I rebased the patch (1st attachment) 
and wrote some followup changes (2nd attachment) and installed them into the 
Savannah master.

> If a pattern has any multibyte character, grep -F is still slow.

Suppose all the multibyte characters in the pattern are non-letters, so that 
case-folding does not affect them. Could grep -iF be fast in that case?

Is the problem that some encodings allow two different representations for the 
same character, and we want the pattern to match both representations?

0001-grep-speed-up-iF-in-multibyte-locales.txt
Description: Text document

0002-grep-avoid-code-duplication-with-iF.txt
Description: Text document