From f34af1aa63da301ae7ee91e2300dff31702001f0 Mon Sep 17 00:00:00 2001
From: Francois-Xavier Le Bail <devel.fx.lebail@orange.fr>
Date: Mon, 29 Oct 2018 22:28:53 +0100
Subject: [PATCH] Compile with '-Wsign-compare' in devel mode if supported

---
 aclocal.m4 |  1 +
 configure  | 43 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/aclocal.m4 b/aclocal.m4
index bb322371..2b45203d 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -879,6 +879,7 @@ AC_DEFUN(AC_LBL_DEVEL,
 		    AC_LBL_CHECK_COMPILER_OPT($1, -Wpedantic)
 		    AC_LBL_CHECK_COMPILER_OPT($1, -Wpointer-arith)
 		    AC_LBL_CHECK_COMPILER_OPT($1, -Wshadow)
+		    AC_LBL_CHECK_COMPILER_OPT($1, -Wsign-compare)
 		    AC_LBL_CHECK_COMPILER_OPT($1, -Wstrict-prototypes)
 		    AC_LBL_CHECK_COMPILER_OPT($1, -Wunreachable-code-return)
 		    AC_LBL_CHECK_COMPILER_OPT($1, -Wused-but-marked-unused)
diff --git a/configure b/configure
index b76db520..25ffe864 100755
--- a/configure
+++ b/configure
@@ -7135,6 +7135,49 @@ fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 
 
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -Wsign-compare option" >&5
+$as_echo_n "checking whether the compiler supports the -Wsign-compare option... " >&6; }
+	save_CFLAGS="$CFLAGS"
+	if expr "x-Wsign-compare" : "x-W.*" >/dev/null
+	then
+	    CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wsign-compare"
+	elif expr "x-Wsign-compare" : "x-f.*" >/dev/null
+	then
+	    CFLAGS="$CFLAGS -Werror -Wsign-compare"
+	elif expr "x-Wsign-compare" : "x-m.*" >/dev/null
+	then
+	    CFLAGS="$CFLAGS -Werror -Wsign-compare"
+	else
+	    CFLAGS="$CFLAGS -Wsign-compare"
+	fi
+	cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+return 0
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+		CFLAGS="$save_CFLAGS"
+		V_CCOPT="$V_CCOPT -Wsign-compare"
+
+else
+
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+		CFLAGS="$save_CFLAGS"
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+
 	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -Wstrict-prototypes option" >&5
 $as_echo_n "checking whether the compiler supports the -Wstrict-prototypes option... " >&6; }
 	save_CFLAGS="$CFLAGS"
-- 
2.39.5