bug: Lua can generate wrong code in functions with too many constants

1 files changed, 6 insertions, 3 deletions

diff --git a/lcode.c b/lcode.c
index 88a72df9..8bc85408 100644
--- a/lcode.c
+++ b/lcode.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lcode.c,v 2.109 2016/05/13 19:09:21 roberto Exp roberto $
+** $Id: lcode.c,v 2.110 2016/06/20 19:12:46 roberto Exp roberto $
 ** Code generator for Lua
 ** See Copyright Notice in lua.h
 */
@@ -1015,11 +1015,14 @@ static void codeunexpval (FuncState *fs, OpCode op, expdesc *e, int line) {
 ** (everything but logical operators 'and'/'or' and comparison
 ** operators).
 ** Expression to produce final result will be encoded in 'e1'.
+** Because 'luaK_exp2RK' can free registers, its calls must be
+** in "stack order" (that is, first on 'e2', which may have more
+** recent registers to be released).
 */
 static void codebinexpval (FuncState *fs, OpCode op,
                            expdesc *e1, expdesc *e2, int line) {
-  int rk1 = luaK_exp2RK(fs, e1);  /* both operands are "RK" */
-  int rk2 = luaK_exp2RK(fs, e2);
+  int rk2 = luaK_exp2RK(fs, e2);  /* both operands are "RK" */
+  int rk1 = luaK_exp2RK(fs, e1);
   freeexps(fs, e1, e2);
   e1->u.info = luaK_codeABC(fs, op, 0, rk1, rk2);  /* generate opcode */
   e1->k = VRELOCABLE;  /* all those operations are relocatable */