C99 compatibility fixes for the configure script

Related to:

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

emacs-configure-c99-1.patch

@@ -0,0 +1,51 @@
+Remove obsolete a.out linker test.  It contains an implicit
+function declaration, leading to false positives.
+
+Submitted upstream:
+
+  <https://lists.gnu.org/archive/html/emacs-devel/2022-12/msg01019.html>
+
+diff --git a/configure.ac b/configure.ac
+index 660784347bbc0dcd..cc390d40b33a1d8f 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -2493,39 +2493,6 @@ if test "${HAVE_X11}" = "yes"; then
+     export LD_RUN_PATH
+   fi
+ 
+-  if test "${opsys}" = "gnu-linux"; then
+-    AC_CACHE_CHECK([whether X on GNU/Linux needs -b to link], [emacs_cv_b_link],
+-    [AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],
+-     [[XOpenDisplay ("foo");]])],
+-     [xgnu_linux_first_failure=no],
+-     [xgnu_linux_first_failure=yes])
+-    if test "${xgnu_linux_first_failure}" = "yes"; then
+-      OLD_CPPFLAGS="$CPPFLAGS"
+-      OLD_LIBS="$LIBS"
+-      CPPFLAGS="$CPPFLAGS -b i486-linuxaout"
+-      LIBS="$LIBS -b i486-linuxaout"
+-      AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],
+-       [[XOpenDisplay ("foo");]])],
+-       [xgnu_linux_second_failure=no],
+-       [xgnu_linux_second_failure=yes])
+-      if test "${xgnu_linux_second_failure}" = "yes"; then
+-	# If we get the same failure with -b, there is no use adding -b.
+-	# So leave it out.  This plays safe.
+-        emacs_cv_b_link=no
+-      else
+-        emacs_cv_b_link=yes
+-      fi
+-      CPPFLAGS=$OLD_CPPFLAGS
+-      LIBS=$OLD_LIBS
+-    else
+-      emacs_cv_b_link=no
+-    fi])
+-    if test "x$emacs_cv_b_link" = xyes ; then
+-      LD_SWITCH_X_SITE="$LD_SWITCH_X_SITE -b i486-linuxaout"
+-      C_SWITCH_X_SITE="$C_SWITCH_X_SITE -b i486-linuxaout"
+-    fi
+-  fi
+-
+   # Reportedly, some broken Solaris systems have XKBlib.h but are missing
+   # header files included from there.
+   AC_CACHE_CHECK([for Xkb], [emacs_cv_xkb],

emacs-configure-c99-2.patch

@@ -0,0 +1,19 @@
+Avoid an implicit declaration of the malloc function.  Improves C99
+compatibility.
+
+Submitted upstream:
+
+  <https://lists.gnu.org/archive/html/emacs-devel/2022-12/msg01020.html>
+
+diff --git a/configure.ac b/configure.ac
+index cc390d40b33a1d8f..7be08de740cfc486 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -4590,6 +4590,7 @@ AC_CACHE_CHECK([whether signals can be handled on alternate stack],
+ 	       [emacs_cv_alternate_stack],
+   [AC_COMPILE_IFELSE(
+      [AC_LANG_PROGRAM([[#include <signal.h>
++			#include <stdlib.h>
+ 		      ]],
+ 		      [[stack_t ss;
+ 			struct sigaction sa;

emacs.spec

@@ -5,7 +5,7 @@ Summary:       GNU Emacs text editor
 Name:          emacs
 Epoch:         1
 Version:       28.1
-Release:       3%{?dist}
+Release:       4%{?dist}
 License:       GPLv3+ and CC0
 URL:           http://www.gnu.org/software/emacs/
 Source0:       https://ftp.gnu.org/gnu/emacs/emacs-%{version}.tar.xz
@@ -25,6 +25,8 @@ Patch1:        emacs-spellchecker.patch
 Patch2:        emacs-system-crypto-policies.patch
 Patch3:        emacs-libdir-vs-systemd.patch
 Patch4:        emacs-pdmp-fingerprint.patch
+Patch5:        emacs-configure-c99-1.patch
+Patch6:        emacs-configure-c99-2.patch
 
 BuildRequires: gcc
 BuildRequires: atk-devel
@@ -205,6 +207,8 @@ cp -p %{SOURCE3} lib/
 %patch2 -p1 -b .system-crypto-policies
 %patch3 -p1 -b .libdir-vs-systemd
 %patch4 -p1 -b .pdmp-fingerprint
+%patch5 -p1
+%patch6 -p1
 autoconf
 
 grep -v "tetris.elc" lisp/Makefile.in > lisp/Makefile.in.new \
@@ -512,6 +516,9 @@ desktop-file-validate %{buildroot}/%{_datadir}/applications/*.desktop
 %{_includedir}/emacs-module.h
 
 %changelog
+* Fri Dec 23 2022 Florian Weimer <fweimer@redhat.com> - 1:28.1-4
+- C99 compatibility fixes for the configure script
+
 * Thu Jul 21 2022 Fedora Release Engineering <releng@fedoraproject.org> - 1:28.1-3
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_37_Mass_Rebuild