Port configure script to C99

Related to:

  <https://fedoraproject.org/wiki/Changes/PortingToModernC>
  <https://fedoraproject.org/wiki/Toolchain/PortingToModernC>

pam-1.5.2-configure-c99.patch

@@ -0,0 +1,35 @@
+From f07fc9cac78851d3dfad1e8c54ee2671e6351853 Mon Sep 17 00:00:00 2001
+From: Sam James <sam@gentoo.org>
+Date: Sun, 11 Sep 2022 16:37:59 +0100
+Subject: [PATCH] configure.ac: fix implicit function declaration in mail spool
+ directory check
+
+Fixes the following error with Clang 15 (which makes implicit function
+declarations an error by default):
+```
++error: call to undeclared library function 'exit' with type 'void (int) __attribute__((noreturn))'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
+ exit(0);
+ ^
+ note: include the header <stdlib.h> or explicitly provide a declaration for 'exit'
+```
+
+Signed-off-by: Sam James <sam@gentoo.org>
+---
+ configure.ac | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/configure.ac b/configure.ac
+index 79113ad1..b12c8892 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -297,6 +297,7 @@ if test x$with_mailspool != x ; then
+ else
+ 	AC_RUN_IFELSE([AC_LANG_SOURCE([[
+ #include <paths.h>
++#include <stdlib.h>
+ int main() {
+ #ifdef _PATH_MAILDIR
+ exit(0);
+-- 
+2.40.0
+

pam.spec

@@ -4,7 +4,7 @@
 Summary: An extensible library which provides authentication for applications
 Name: pam
 Version: 1.5.2
-Release: 17%{?dist}
+Release: 18%{?dist}
 # The library is BSD licensed with option to relicense as GPLv2+
 # - this option is redundant as the BSD license allows that anyway.
 # pam_timestamp and pam_loginuid modules are GPLv2+.
@@ -26,6 +26,7 @@ Patch1:  pam-1.5.2-redhat-modules.patch
 Patch2:  pam-1.5.0-noflex.patch
 Patch3:  pam-1.3.0-unix-nomsg.patch
 Patch4:  pam-1.5.2-pwhistory-config.patch
+Patch5:  pam-1.5.2-configure-c99.patch
 
 %{load:%{SOURCE3}}
 
@@ -120,6 +121,7 @@ cp %{SOURCE18} .
 %patch2 -p1 -b .noflex
 %patch3 -p1 -b .nomsg
 %patch4 -p1 -b .pwhistory-config
+%patch5 -p1 -b .configure-c99
 
 autoreconf -i
 
@@ -355,6 +357,9 @@ done
 %{_pam_libdir}/libpam_misc.so.%{so_ver}*
 
 %changelog
+* Tue Apr 25 2023 Arjun Shankar <arjun@redhat.com> - 1.5.2-18
+- Port configure script to C99
+
 * Thu Feb  9 2023 Iker Pedrosa <ipedrosa@redhat.com> - 1.5.2-17
 - Remove pam_console (#2166692)
 - Rebase to pam-redhat-1.2.0