bug#64242: [PATCH] Fix VC package build when there is no docs dir

[Philip Kaludercic <philipk@posteo.net>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Daniel Semyonov <daniel@dsemy.com>
>> Cc: 64242@debbugs.gnu.org
>> Date: Fri, 23 Jun 2023 09:32:01 +0300
>> 
>> >>>>> Eli Zaretskii writes:
>> 
>>     > What do you mean by "isn't a directory"?  FILE is supposed to be a
>>     > documentation file, not a directory, see the doc string of this
>>     > function.  Do you mean that FILE is a relative file name so that
>>     > file-name-directory returns nil for it?  If so, I think the
>>     > correct fix would be to reverse the order:
>> 
>>     >   (docs-directory (file-name-directory (expand-file-name file)))
>> 
>> Yeah, you're completely right, this was a misunderstanding on my part;
>> my fix just happened to also work so I made some incorrect assumptions.
>> 
>> After some further testing, this seems to happen for packages for which
>> the doc file is in the base directory of the package (which causes
>> 'file-name-directory' to return nil as the doc file name is relative to
>> the package dir).
>> 
>> I attached an updated patch.
>> 
>>     > Can you show a recipe to reproduce this problem, preferably
>>     > starting from "emacs -Q"?
>> 
>> 1. $ emacs -Q
>> 2. M-x package-vc-install RET eat RET
>> 3. A few seconds later,
>>    "package-vc--unpack-1: Wrong type argument: stringp, nil"
>> 
>>     > And finally, this issue exists on the emacs-29 release branch as
>>     > well, doesn't it?
>> 
>> I haven't tested it, but I don't see a reason it wont.
>
> Philip, any comments or objections to installing this on the emacs-29
> branch?

I have none.  There were just come complains last time, because we made
the change too soon, so I believe the consensus was to wait for a bit
longer and then it was just forgotten.

> Thanks.