#1071041 grep: Buggy multi-character collating symbol/equivalent class

Package:
grep
Source:
grep
Description:
GNU grep, egrep and fgrep
Submitter:
Date:
2024-05-13 11:06:04 UTC
Severity:
normal
#1071041#5
Date:
2024-05-13 10:22:23 UTC
From:
To:
These three commands should all return patch, but the last one does not
(and is buggy):

$ echo patch | LC_ALL=cs_CZ grep '[[.ch.]]$'
patch
$ echo patch | LC_ALL=cs_CZ grep 't[[=ch=]]$'
patch
$ echo patch | LC_ALL=cs_CZ grep '[[=ch=]]$'
$