Re: Regression: git no longer works with musl libc's regex impl

On 06/10/16 20:18, Ævar Arnfjörð Bjarmason wrote:

On Tue, Oct 4, 2016 at 6:08 PM, Johannes Schindelin
[off-list ref] wrote:

quoted

As to making NO_REGEX conditional on REG_STARTEND: you are talking about
apples and oranges here. NO_REGEX is a Makefile flag, while REG_STARTEND
is a C preprocessor macro.

Unless you can convince the rest of the Git developers (you would not
convince me) to simulate autoconf by compiling an executable every time
`make` is run, to determine whether REG_STARTEND is defined, this is a
no-go.

But just to clarify, does anyone have any objection to making our
configure.ac compile a C program to check for this sort of thing?
Because that seems like the easiest solution to this class of problem.

Err, you do know that we already do that, right?

[see commit a1e3b669 ("autoconf: don't use platform regex if it lacks REG_STARTEND", 17-08-2010)]

In fact, if you run the auto tools on cygwin, you get a different setting
for NO_REGEX than via config.mak.uname. Which is why I don't run configure
on cygwin. :-D

[The issue is exposed by t7008-grep-binary.sh, where the cygwin native
regex library matches '.' in a pattern with the NUL character. ie the
test_expect_failure test passes.]

ATB,
Ramsay Jones