bin/57106: /usr/bin/vi doesn't handle correctly backslash in ex_line

[jbgg%disroot.org@localhost]

>Number:         57106
>Category:       bin
>Synopsis:       /usr/bin/vi doesn't handle correctly backslash in ex_line
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Dec 10 23:10:00 +0000 2022
>Originator:     Bosco G. G.
>Release:        NetBSD 7.3
>Organization:
>Environment:
NetBSD localhost 9.3 NetBSD 9.3 (GENERIC) #0: Thu Aug  4 15:30:37 UTC 2022  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64
>Description:
The editor vi doesn't handle correctly backslash when a searching.
>How-To-Repeat:
$ printf '%s\n' '/' '\' > test.txt

Opening test.txt with vi and searching with
/\\/
doesn't catch the backslash but the slash.
>Fix: