Subject: bug#51800: 29.0.50; vc-{cvs,dav,rcs,sccs}-responsible-p should not return t

From: TAKAHASHI Yoshio <[email-masked]>
Date: Sat, 13 Nov 2021 10:24:20 +0900

Hi,

vc-*-responsible-p should not return t.
it should return nil or path string.

for example, `vc-rcs-responsible-p' returns the result of
`file-directory-p', that is t or nil.
if it returns t, the caller, `vc-backend-for-registration', raises an
error, because it expects SEQUENCE.

-- 
tkh