From ce851b5df50ffbd3c2a518b93f773ebbb400cb20 Mon Sep 17 00:00:00 2001
From: belliash <belliash@codingworkshop.eu.org>
Date: Thu, 6 Jun 2019 20:32:12 +0200
Subject: [PATCH] Do not try to load constant on OP_IS.

---
 engine/vm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/engine/vm.c b/engine/vm.c
index 4273f7a..51df0e2 100644
--- a/engine/vm.c
+++ b/engine/vm.c
@@ -2432,7 +2432,7 @@ static sxi32 VmByteCodeExec(
 					pTos++;
 					if((pObj = (ph7_value *)SySetAt(&pVm->aLitObj, pInstr->iP2)) != 0) {
 						if(pInstr->iP1 == 1 && SyBlobLength(&pObj->sBlob) <= 64) {
-							if(pInstr[1].iOp != PH7_OP_MEMBER && pInstr[1].iOp != PH7_OP_NEW) {
+							if(pInstr[1].iOp != PH7_OP_MEMBER && pInstr[1].iOp != PH7_OP_NEW && pInstr[1].iOp != PH7_OP_IS) {
 								/* Point to the top active frame */
 								VmFrame *pFrame = pVm->pFrame;
 								while(pFrame->pParent && (pFrame->iFlags & VM_FRAME_EXCEPTION)) {
@@ -2462,7 +2462,7 @@ static sxi32 VmByteCodeExec(
 									/* Mark as constant */
 									pTos->nIdx = SXU32_HIGH;
 									break;
-								} else if(pInstr[2].iOp != PH7_OP_MEMBER && pInstr[2].iOp != PH7_OP_NEW) {
+								} else if(pInstr[2].iOp != PH7_OP_MEMBER && pInstr[2].iOp != PH7_OP_NEW && pInstr[2].iOp != PH7_OP_IS) {
 									PH7_VmThrowError(&(*pVm), PH7_CTX_ERR,
 													"Call to undefined constant ‘%s’", SyBlobData(&pObj->sBlob));
 								}