issue #163 Fix bug in OP_RETURN in interpreter and MIR JIT backend; we need to reload RA after call to luaF_close() as stack may been reallocated

src/lvm.c

@@ -1809,8 +1809,10 @@ int luaV_execute (lua_State *L) {
       vmcase(OP_RETURN) {
         int b = GETARG_B(i);
 #ifdef RAVI_DEFER_STATEMENT
-        if (cl->p->sizep > 0)
+        if (cl->p->sizep > 0) {
           Protect_base(luaF_close(L, base, LUA_OK));
+          ra = RA(i);
+        }
 #else
         if (cl->p->sizep > 0) luaF_close(L, base);
 #endif

src/ravi_jitshared.c

@@ -1062,7 +1062,6 @@ static void emit_op_loadk(struct function *fn, int A, int Bx, int pc) {
 
 static void emit_op_return(struct function *fn, int A, int B, int pc) {
   (void)pc;
-  emit_reg(fn, "ra", A);
 #ifdef RAVI_DEFER_STATEMENT
   membuff_add_string(&fn->body, "if (cl->p->sizep > 0) {\n luaF_close(L, base, LUA_OK);\n");
   membuff_add_string(&fn->body, " base = ci->u.l.base;\n");
@@ -1070,6 +1069,7 @@ static void emit_op_return(struct function *fn, int A, int B, int pc) {
 #else
   membuff_add_string(&fn->body, "if (cl->p->sizep > 0) luaF_close(L, base);\n");
 #endif
+  emit_reg(fn, "ra", A);
   membuff_add_fstring(&fn->body, "result = (%d != 0 ? %d - 1 : cast_int(L->top - ra));\n", B, B);
   membuff_add_string(&fn->body, "return luaD_poscall(L, ci, ra, result);\n");
 }

tests/language/ravi_tests1.ravi

@@ -1891,6 +1891,24 @@ compile(x)
 x()
 print 'Test 83 OK'
 
+--- Test stack reallocation in defer statement
+function x(a) if a <= 0 then return else x(a-1) end end
+y = ravi.jit and 100 or 1000
+function z(...)
+    -- recursive call to make stack
+	defer x(y) end
+	return ...
+end
+do
+  local a,b,c = z(1,2,3)
+  assert(a == 1 and b == 2 and c == 3)
+  compile(x)
+  compile(z)
+  a,b,c = z(3,2,1)
+  assert(a == 3 and b == 2 and c == 1)
+end
+print 'Test 84 OK'
+
 for k,v in pairs(opcodes_coverage)
 do
   print(k, v)