Index: configure
===================================================================
--- configure	(Revision 59488)
+++ configure	(Arbeitskopie)
@@ -4427,25 +4427,29 @@
 then
     case $GCC in
     yes)
-        if test "$CC" != 'g++' ; then
+	if test "$CC" != 'g++' ; then
 	    STRICT_PROTO="-Wstrict-prototypes"
 	fi
-        # For gcc 4.x we need to use -fwrapv so lets check if its supported
-        if "$CC" -v --help 2>/dev/null |grep -- -fwrapv > /dev/null; then
-           WRAP="-fwrapv"
-        fi
+	# For gcc 4.x we need to use -fwrapv so lets check if its supported
+	if "$CC" -v --help 2>/dev/null |grep -- -fwrapv > /dev/null; then
+		WRAP="-fwrapv"
+	fi
+	# For gcc 4.x we use -Wstrict-overflow for extra warnings
+	if "$CC" -v --help 2>/dev/null |grep -- -Wstrict-overflow > /dev/null; then
+		STRICT_OVERFLOW="-Wstrict-overflow"
+	fi
 	case $ac_cv_prog_cc_g in
 	yes)
 	    if test "$Py_DEBUG" = 'true' ; then
 		# Optimization messes up debuggers, so turn it off for
 		# debug builds.
-		OPT="-g -Wall $STRICT_PROTO"
+		OPT="-std=gnu89 -g -Wall -Werror $STRICT_PROTO $STRICT_OVERFLOW"
 	    else
-		OPT="-g $WRAP -O3 -Wall $STRICT_PROTO"
+		OPT="-std=gnu89 -g $WRAP -O3 -Wall -Werror $STRICT_PROTO $STRICT_OVERFLOW"
 	    fi
 	    ;;
 	*)
-	    OPT="-O3 -Wall $STRICT_PROTO"
+	    OPT="-O3 -Wall -Werror $STRICT_PROTO"
 	    ;;
 	esac
 	case $ac_sys_system in
Index: configure.in
===================================================================
--- configure.in	(Revision 59488)
+++ configure.in	(Arbeitskopie)
@@ -754,25 +754,29 @@
 then
     case $GCC in
     yes)
-        if test "$CC" != 'g++' ; then
+	if test "$CC" != 'g++' ; then
 	    STRICT_PROTO="-Wstrict-prototypes"
 	fi
-        # For gcc 4.x we need to use -fwrapv so lets check if its supported
-        if "$CC" -v --help 2>/dev/null |grep -- -fwrapv > /dev/null; then
-           WRAP="-fwrapv"
-        fi
+	# For gcc 4.x we need to use -fwrapv so lets check if its supported
+	if "$CC" -v --help 2>/dev/null |grep -- -fwrapv > /dev/null; then
+		WRAP="-fwrapv"
+	fi
+	# For gcc 4.x we use -Wstrict-overflow for extra warnings
+	if "$CC" -v --help 2>/dev/null |grep -- -Wstrict-overflow > /dev/null; then
+		STRICT_OVERFLOW="-Wstrict-overflow"
+	fi
 	case $ac_cv_prog_cc_g in
 	yes)
 	    if test "$Py_DEBUG" = 'true' ; then
 		# Optimization messes up debuggers, so turn it off for
 		# debug builds.
-		OPT="-g -Wall $STRICT_PROTO"
+		OPT="-std=gnu89 -g -Wall -Werror $STRICT_PROTO $STRICT_OVERFLOW"
 	    else
-		OPT="-g $WRAP -O3 -Wall $STRICT_PROTO"
+		OPT="-std=gnu89 -g $WRAP -O3 -Wall -Werror $STRICT_PROTO $STRICT_OVERFLOW"
 	    fi
 	    ;;
 	*)
-	    OPT="-O3 -Wall $STRICT_PROTO"
+	    OPT="-O3 -Wall -Werror $STRICT_PROTO"
 	    ;;
 	esac
 	case $ac_sys_system in