From 4210c6dd4c7726af12ab8c3ca6785c620f4723ce Mon Sep 17 00:00:00 2001
From: Christopher Willis-Ford <cwillisf@media.mit.edu>
Date: Wed, 14 Mar 2018 16:17:29 -0700
Subject: [PATCH] Fix stack check in `stepThread`
The previous logic seemed to be expecting `peekStack` to return 0 when
the stack was empty, but its return type is `?string` and it returns
`undefined` when the stack is empty. The `!== 0` check would never pass,
then, leading to problems with (for example) the "say/think and wait"
blocks.
---
src/engine/sequencer.js | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/engine/sequencer.js b/src/engine/sequencer.js
index 2db6054b7..ce65163d4 100644
--- a/src/engine/sequencer.js
+++ b/src/engine/sequencer.js
@@ -175,7 +175,7 @@ class Sequencer {
thread.popStack();
}
// Save the current block ID to notice if we did control flow.
- while ((currentBlockId = thread.peekStack()) !== 0) {
+ while ((currentBlockId = thread.peekStack())) {
let isWarpMode = thread.peekStackFrame().warpMode;
if (isWarpMode && !thread.warpTimer) {
// Initialize warp-mode timer if it hasn't been already.