Merge pull request #1405 from mmcgr/overflow

Assume 2's complement when compiling

Author: Bernhard Scholz

configure.ac

@@ -32,7 +32,7 @@ AC_CONFIG_MACRO_DIR([m4])
 
 dnl Do not set default CFLAGS and CXXFLAGS
 ENV_CXXFLAGS="$CXXFLAGS"
-CXXFLAGS=""
+CXXFLAGS=" -fwrapv "
 
 # Disable provenance
 AC_ARG_ENABLE(