[PATCH 4/3] xap_helper_cxx: accept leading spaces from pkg-config

[Eric Wong <e@80x24.org>]

Eric Wong <e@80x24.org> wrote:
> Avoid mixing autodie use in different scopes since it's likely
> to cause problems like it did in Gcf2.  While none of these
> fix known problems with test cases, it's likely worthwhile to
> avoid it anyways to avoid future surprises.

>  lib/PublicInbox/XapHelperCxx.pm | 18 ++++++++----------

That XapHelperCxx change was totally necessary for running the
C++ build on CentOS 7.x (but the test is auto-skipped on any
build failure), as is this one:

--------8<--------
Subject: [PATCH] xap_helper_cxx: accept leading spaces from pkg-config

pkg-config 0.27.1 and xapian14-core-devel (1.4.24-1.el7) on
CentOS 7.x will print a leading space when running
`pkg-config --libs --cflags xapian-core'.  This leading
space creates an empty string when `split' with /\s+/ as
a pattern.  Instead, use the documented ' ' (SP) character
to put split into "awk mode" which eats leading (and
redundant) spaces and tabs.
---
 lib/PublicInbox/XapHelperCxx.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/PublicInbox/XapHelperCxx.pm b/lib/PublicInbox/XapHelperCxx.pm
index 1250c964..9e819546 100644
--- a/lib/PublicInbox/XapHelperCxx.pm
+++ b/lib/PublicInbox/XapHelperCxx.pm
@@ -86,7 +86,7 @@ sub build () {
 	# distributed packages.
 	$^O eq 'netbsd' and $fl =~ s/(\A|[ \t])\-L([^ \t]+)([ \t]|\z)/
 				"$1-L$2 -Wl,-rpath=$2$3"/egsx;
-	my @xflags = split(/\s+/, "$fl $xflags");
+	my @xflags = split(' ', "$fl $xflags"); # ' ' awk-mode eats leading WS
 	my @cflags = grep(!/\A-(?:Wl|l|L)/, @xflags);
 	run_die([$cxx, '-c', "$prog.cpp", @cflags]);
 	run_die([$cxx, '-o', "$prog.tmp", "$prog.o", @xflags]);