From: Junio C Hamano <gitster@pobox.com>
Date: Mon, 09 Apr 2018 04:54:31 GMT
Subject: Re: [PATCH 1/1] perl: fix installing modules from contrib
Message-ID: <xmqqpo39569k.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <87tvssva2c.fsf@evledraar.gmail.com>

Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:

>>
>> +perllibdir:
>> +	@echo $(perllibdir_SQ)

This use of _SQ variant is fishy, isn't it?  Judging from the output
of 

    $ git grep _SQ Makefile

e.g.

    Makefile:	$(INSTALL) $^ '$(DESTDIR_SQ)$(gitexec_instdir_SQ)'
    Makefile:	$(INSTALL) $^ '$(DESTDIR_SQ)$(gitexec_instdir_SQ)'
    Makefile:	$(INSTALL) $^ '$(DESTDIR_SQ)$(gitexec_instdir_SQ)'

I'd expect that any _SQ variant must be referenced inside a single
quote pair.  In fact, that is why a single quote (and nothing else)
in the base variable is replaced with the magic "'\''" sequence,
first stepping out of the current sq context, append a single sq
(escaped with a backslash from the shell), and then stepping back
into another sq context.

I think nobody saw breakage only because they do not have two
consecutive SPs (or any single quote) in their path to $perllibdir.
If we depend on such limitation, there is no point using _SQ
variant, but we already have _SQ variant, let's use it correctly.