use unsigneds for unary minus, too

lbaselib.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lbaselib.c,v 1.278 2013/07/05 14:35:49 roberto Exp roberto $
+** $Id: lbaselib.c,v 1.279 2013/07/05 14:39:15 roberto Exp roberto $
 ** Basic library
 ** See Copyright Notice in lua.h
 */
@@ -63,7 +63,7 @@ static int b_str2int (const char *s, const char *e, int base, lua_Integer *pn) {
   s += strspn(s, SPACECHARS);  /* skip trailing spaces */
   if (s != e)  /* invalid trailing characters? */
     return 0;
-  *pn = (neg) ? -(lua_Integer)n : (lua_Integer)n;
+  *pn = (lua_Integer)((neg) ? (0u - n) : n);
   return 1;
 }
 

lobject.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lobject.c,v 2.66 2013/06/04 19:36:42 roberto Exp roberto $
+** $Id: lobject.c,v 2.67 2013/06/25 18:58:32 roberto Exp roberto $
 ** Some generic functions over Lua objects
 ** See Copyright Notice in lua.h
 */
@@ -78,7 +78,7 @@ static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
     case LUA_OPMUL:return intop(*, v1, v2);
     case LUA_OPMOD: return luaV_mod(L, v1, v2);
     case LUA_OPPOW: return luaV_pow(v1, v2);
-    case LUA_OPUNM: return -v1;
+    case LUA_OPUNM: return intop(-, 0, v1);
     default: lua_assert(0); return 0;
   }
 }
@@ -260,8 +260,7 @@ int luaO_str2int (const char *s, size_t len, lua_Integer *result) {
   while (lisspace(cast_uchar(*s))) s++;  /* skip trailing spaces */
   if (empty || s != ends) return 0;  /* something wrong in the numeral */
   else {
-    if (neg) *result = -cast(lua_Integer, a);
-    else *result = cast(lua_Integer, a);
+    *result = cast_integer((neg) ? 0u - a : a);
     return 1;
   }
 }

lvm.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 2.174 2013/06/19 14:27:00 roberto Exp roberto $
+** $Id: lvm.c,v 2.175 2013/06/20 15:02:49 roberto Exp roberto $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -334,7 +334,7 @@ lua_Integer luaV_div (lua_State *L, lua_Integer x, lua_Integer y) {
     if (y == 0)
       luaG_runerror(L, "attempt to divide by zero");
     else  /* -1 */
-      return -x;   /* avoid overflow with 0x80000... */
+      return intop(-, 0, x);   /* avoid overflow with 0x80000... */
   }
   else {
     lua_Integer d = x / y;  /* perform division */
@@ -699,7 +699,7 @@ void luaV_execute (lua_State *L) {
         lua_Number nb;
         if (ttisinteger(rb)) {
           lua_Integer ib = ivalue(rb);
-          setivalue(ra, -ib);
+          setivalue(ra, intop(-, 0, ib));
         }
         else if (tonumber(rb, &nb)) {
           setnvalue(ra, luai_numunm(L, nb));