lib/58618: mbrtocN(3) fails to keep shift state

[campbell+netbsd%mumble.net@localhost]

>Number:         58618
>Category:       lib
>Synopsis:       mbrtocN(3) fails to keep shift state
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Aug 19 12:30:00 +0000 2024
>Originator:     Taylor R Campbell
>Release:        current
>Organization:
The mbrtoNetBSD Foundation
>Environment:
>Description:
I drafted mbrtoc8, mbrtoc16, and mbrtoc32 last week for C11/C23 compliance, but the way I did it fails to keep state to process shift sequences incrementally, as in, e.g., ISO-2022-JP.
>How-To-Repeat:
Process a shift sequence like ESC ( J, and then process subsequent input under the assumption of that shift sequence.
>Fix:
Yes, please!