dev-libs/apr: Fixed build with sys-devel/autoconf-2.70

Thanks-to: Sergei Trofimovich <[email protected]>
Closes: https://bugs.gentoo.org/750353
Package-Manager: Portage-3.0.12, Repoman-3.0.2
Signed-off-by: Lars Wendler <[email protected]>

dev-libs/apr/apr-1.7.0-r1.ebuild

@@ -30,6 +30,7 @@ PATCHES=(
 	"${FILESDIR}"/${PN}-1.5.0-cross-types.patch
 	"${FILESDIR}"/${PN}-1.5.0-sysroot.patch #385775
 	"${FILESDIR}"/${PN}-1.6.3-skip-known-failing-tests.patch
+	"${FILESDIR}"/${PN}-1.7.0-autoconf-2.70.patch #750353
 )
 
 src_prepare() {

dev-libs/apr/files/apr-1.7.0-autoconf-2.70.patch

@@ -0,0 +1,64 @@
+From 5593f23e8e062da108ed585535e7281b87346ee1 Mon Sep 17 00:00:00 2001
+From: Sergei Trofimovich <[email protected]>
+Date: Wed, 25 Nov 2020 09:36:25 +0000
+Subject: [PATCH] build/apr_common.m4: avoid explicit inclusion of
+ '"confdefs.h"'
+
+The failure is observed on `autoconf-2.69d` (soon to be released
+as `autoconf-2.70`). There `int64_t` detection fails as:
+
+```
+$ autoreconf && ./configure
+...
+checking whether int64_t and int use fmt %d... no
+checking whether int64_t and long use fmt %ld... no
+checking whether int64_t and long long use fmt %lld... no
+configure: error: could not determine the string function for int64_t
+```
+
+This happens because `./configure` always stumbles on warning:
+
+```
+configure:3350: gcc -c -g -O2 -Werror  conftest.c >&5
+In file included from conftest.c:31:
+confdefs.h:22: error: "__STDC_WANT_IEC_60559_ATTRIBS_EXT__" redefined [-Werror]
+   22 | #define __STDC_WANT_IEC_60559_ATTRIBS_EXT__ 1
+      |
+```
+
+It's triggered by double inclusion of `"confdefs.h"` contents:
+explicitly in `APR_TRY_COMPILE_NO_WARNING` macro and implicitly
+via `AC_LANG_SOURCE` use.
+
+To fix it and avoid having to define `main()` declaration the change
+uses `AC_LANG_PROGRAM` instead.
+
+Tested on both `autoconf-2.69` and `autoconf-2.69d`.
+
+Bug: https://bugs.gentoo.org/738156
+Bug: https://bugs.gentoo.org/750353
+Signed-off-by: Sergei Trofimovich <[email protected]>
+---
+ build/apr_common.m4 | 8 ++------
+ 1 file changed, 2 insertions(+), 6 deletions(-)
+
+diff --git a/build/apr_common.m4 b/build/apr_common.m4
+index f4e2dfd0a7..6f5782e674 100644
+--- a/build/apr_common.m4
++++ b/build/apr_common.m4
+@@ -504,13 +504,9 @@ AC_DEFUN([APR_TRY_COMPILE_NO_WARNING],
+    CFLAGS="$CFLAGS -Werror"
+  fi
+  AC_COMPILE_IFELSE(
+-  [AC_LANG_SOURCE(
+-   [#include "confdefs.h"
+-   ]
+-   [[$1]]
+-   [int main(int argc, const char *const *argv) {]
++  [AC_LANG_PROGRAM(
++   [[$1]],
+    [[$2]]
+-   [   return 0; }]
+   )], [CFLAGS=$apr_save_CFLAGS
+ $3],  [CFLAGS=$apr_save_CFLAGS
+ $4])