Port configure script to C99

Related to:

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

lldpd-configure-c99.patch

@@ -0,0 +1,33 @@
+Include <stdio.h> to avoid an implicit declaration of the printf
+function.  Otherwise, the check always fails with compilers that
+do not support implicit function declarations (a C feature removed
+in 1999).
+
+Submitted upstream: <https://github.com/lldpd/lldpd/pull/565>
+
+diff --git a/configure b/configure
+index 931bb75d69c1149d..d34641df4b3d8aed 100755
+--- a/configure
++++ b/configure
+@@ -18675,7 +18675,7 @@ else
+ 
+     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+ /* end confdefs.h.  */
+-
++#include <stdio.h>
+ int
+ main ()
+ {
+diff --git a/m4/progname.m4 b/m4/progname.m4
+index 28ac1748f7005139..63ddda6ab9003e5d 100644
+--- a/m4/progname.m4
++++ b/m4/progname.m4
+@@ -3,7 +3,7 @@
+ #
+ AC_DEFUN([lldp_CHECK___PROGNAME],[
+   AC_CACHE_CHECK([whether libc defines __progname], lldp_cv_check___progname, [
+-    AC_TRY_LINK([],
++    AC_TRY_LINK([#include <stdio.h>],
+ 	[ extern char *__progname; printf("%s", __progname); ],
+ 	[ lldp_cv_check___progname="yes" ],
+ 	[ lldp_cv_check___progname="no" ])

lldpd.spec

@@ -10,7 +10,7 @@
 
 Name:     lldpd
 Version:  1.0.4
-Release:  10%{?dist}
+Release:  11%{?dist}
 Summary:  ISC-licensed implementation of LLDP
 
 License:  ISC
@@ -21,6 +21,7 @@ Source2:  %{name}-tmpfiles
 Source3:  %{name}-fedora.sysconfig
 Source4:  %{name}-el6.init
 Source5:  %{name}-el7.service
+Patch0: lldpd-configure-c99.patch
 
 BuildRequires: gcc
 BuildRequires: readline-devel
@@ -62,7 +63,7 @@ Summary: %{summary}
 %{name} development libraries and headers
 
 %prep
-%autosetup
+%autosetup -p1
 
 
 %build
@@ -173,6 +174,9 @@ fi
 
 
 %changelog
+* Thu Dec  8 2022 Florian Weimer <fweimer@redhat.com> - 1.0.4-11
+- Port configure script to C99
+
 * Thu Jul 21 2022 Fedora Release Engineering <releng@fedoraproject.org> - 1.0.4-10
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_37_Mass_Rebuild