[Buildroot] [PATCH 1/1] package/bird: fix build with autoconf >= 2.70

[Fabrice Fontaine]

Fix the following build failure raised since bump of autoconf to version
2.71 in commit ecd54b65c1f998a7ccd91f7c523e4ff38c4781da:

checking for glob.h... no
configure: error: glob.h not found.

Fixes:
 - http://autobuild.buildroot.org/results/d7aab7df196e0f6d6389b87ff29da7c2971e6b6d

Signed-off-by: Fabrice Fontaine <fontaine.fabrice at gmail.com>
---
 ...gure.ac-fix-build-with-autoconf-2.70.patch | 43 +++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 package/bird/0001-configure.ac-fix-build-with-autoconf-2.70.patch

diff --git a/package/bird/0001-configure.ac-fix-build-with-autoconf-2.70.patch b/package/bird/0001-configure.ac-fix-build-with-autoconf-2.70.patch
new file mode 100644
index 0000000000..b412a55ead
--- /dev/null
+++ b/package/bird/0001-configure.ac-fix-build-with-autoconf-2.70.patch
@@ -0,0 +1,43 @@
+From aa5bc6d2e59c5257d777a45ee4a0e0a784c44244 Mon Sep 17 00:00:00 2001
+From: Fabrice Fontaine <fontaine.fabrice at gmail.com>
+Date: Fri, 5 Nov 2021 20:58:41 +0100
+Subject: [PATCH] configure.ac: fix build with autoconf >= 2.70
+
+On some embedded toolchains, glob.h detection fails because -g is
+wrongly added (even when CFLAGS is overwritten):
+
+configure:5881: checking for glob.h
+configure:5904: /home/giuliobenetti/autobuild/run/instance-2/output-1/host/bin/mips64el-linux-gcc -o conftest -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -Os -g0  -pthread -fno-strict-aliasing -fno-strict-overflow -flto -Wall -Wextra -Wstrict-prototypes -Wno-parentheses -Wno-pointer-sign -Wno-missing-field-initializers -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -pthread -flto=4 -g conftest.c  >&5
+/home/giuliobenetti/autobuild/run/instance-2/output-1/host/opt/ext-toolchain/bin/../lib/gcc/mips64el-buildroot-linux-uclibc/8.4.0/../../../../mips64el-buildroot-linux-uclibc/bin/ld: /tmp/ccldlED9.ltrans0.ltrans.o:(.debug_info+0x2a): undefined reference to `conftest.c.fb729d13'
+/home/giuliobenetti/autobuild/run/instance-2/output-1/host/opt/ext-toolchain/bin/../lib/gcc/mips64el-buildroot-linux-uclibc/8.4.0/../../../../mips64el-buildroot-linux-uclibc/bin/ld: /tmp/ccldlED9.ltrans0.ltrans.o:(.debug_info+0x2f): undefined reference to `conftest.c.fb729d13'
+
+This build failure is raised since autoconf 2.70 and
+https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=76754e04fce5f6a7701bec57b057020585df2ae3
+because ac_test_CFLAGS is now set to ${CFLAGS+y} instead of
+${CFLAGS+set}
+
+Fixes:
+ - http://autobuild.buildroot.org/results/d7aab7df196e0f6d6389b87ff29da7c2971e6b6d
+
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice at gmail.com>
+[Upstream status: sent to bird-users at network.cz]
+---
+ configure.ac | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/configure.ac b/configure.ac
+index 64181d29..b4b3fcfb 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -114,7 +114,7 @@ AC_SEARCH_LIBS([clock_gettime], [rt posix4],
+ AC_CANONICAL_HOST
+ 
+ # Store this value because ac_test_CFLAGS is overwritten by AC_PROG_CC
+-if test "$ac_test_CFLAGS" != set ; then
++if ! test $ac_test_CFLAGS ; then
+   bird_cflags_default=yes
+ fi
+ 
+-- 
+2.33.0
+
-- 
2.33.0