From 149bbb78752cdd84b7c7fd9c720f566cf48aced9 Mon Sep 17 00:00:00 2001
From: Gordon Williams <gw@pur3.co.uk>
Date: Mon, 15 Jan 2024 14:29:21 +0000
Subject: [PATCH] Throw Exception when a Promise tries to resolve with another
 Promise (#2450)

---
 ChangeLog            | 1 +
 src/jswrap_promise.c | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index ccec89e437..24a86161c7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,5 @@
      2v21 : nRF52: free up 800b more flash by removing vector table padding
+            Throw Exception when a Promise tries to resolve with another Promise (#2450)
 
      2v20 : Ensure String.charCodeAt returns NaN for out of bounds chars
             Bangle.js2: When rendering overlays, *do not* use the current FG/BG color for 1 bit overlays
diff --git a/src/jswrap_promise.c b/src/jswrap_promise.c
index aa3ce23c83..9429796db5 100644
--- a/src/jswrap_promise.c
+++ b/src/jswrap_promise.c
@@ -108,6 +108,10 @@ void _jswrap_promise_resolve_or_reject(JsVar *promise, JsVar *data, JsVar *fn) {
 }
 void _jswrap_promise_resolve_or_reject_chain(JsVar *promise, JsVar *data, bool resolve) {
   const char *eventName = resolve ? JS_PROMISE_THEN_NAME : JS_PROMISE_CATCH_NAME;
+  if (_jswrap_promise_is_promise(data)) {
+    jsExceptionHere(JSET_ERROR, "Resolving a Promise with a value that is a Promise is not currently supported");
+    return;
+  }
   // if we didn't have a catch, traverse the chain looking for one
   JsVar *fn = jsvObjectGetChildIfExists(promise, eventName);
   if (!fn) {