Normative: Close sync iterator when async wrapper yields rejection

spec.html

@@ -42957,7 +42957,7 @@ <h1>%AsyncFromSyncIteratorPrototype%.next ( [ _value_ ] )</h1>
             1. Else,
               1. Let _result_ be IteratorNext(_syncIteratorRecord_).
             1. IfAbruptRejectPromise(_result_, _promiseCapability_).
-            1. Return ! AsyncFromSyncIteratorContinuation(_result_, _promiseCapability_).
+            1. Return ! AsyncFromSyncIteratorContinuation(_result_, _promiseCapability_, _syncIteratorRecord_, *true*).
           </emu-alg>
         </emu-clause>
 
@@ -42983,7 +42983,7 @@ <h1>%AsyncFromSyncIteratorPrototype%.return ( [ _value_ ] )</h1>
             1. If Type(_result_) is not Object, then
               1. Perform ! Call(_promiseCapability_.[[Reject]], *undefined*, &laquo; a newly created *TypeError* object &raquo;).
               1. Return _promiseCapability_.[[Promise]].
-            1. Return ! AsyncFromSyncIteratorContinuation(_result_, _promiseCapability_).
+            1. Return ! AsyncFromSyncIteratorContinuation(_result_, _promiseCapability_, _syncIteratorRecord_, *false*).
           </emu-alg>
         </emu-clause>
 
@@ -43009,7 +43009,7 @@ <h1>%AsyncFromSyncIteratorPrototype%.throw ( [ _value_ ] )</h1>
             1. If Type(_result_) is not Object, then
               1. Perform ! Call(_promiseCapability_.[[Reject]], *undefined*, &laquo; a newly created *TypeError* object &raquo;).
               1. Return _promiseCapability_.[[Promise]].
-            1. Return ! AsyncFromSyncIteratorContinuation(_result_, _promiseCapability_).
+            1. Return ! AsyncFromSyncIteratorContinuation(_result_, _promiseCapability_, _syncIteratorRecord_, *false*).
           </emu-alg>
         </emu-clause>
       </emu-clause>
@@ -43046,6 +43046,8 @@ <h1>
           AsyncFromSyncIteratorContinuation (
             _result_: unknown,
             _promiseCapability_: a PromiseCapability Record,
+            _syncIteratorRecord_: unknown,
+            _closeIteratorOnRejection_: a Boolean,
           )
         </h1>
         <dl class="header">
@@ -43062,7 +43064,14 @@ <h1>
             1. Return ! CreateIterResultObject(_value_, _done_).
           1. Let _onFulfilled_ be ! CreateBuiltinFunction(_unwrap_, 1, *""*, &laquo; &raquo;).
           1. NOTE: _onFulfilled_ is used when processing the *"value"* property of an IteratorResult object in order to wait for its value if it is a promise and re-package the result in a new "unwrapped" IteratorResult object.
-          1. Perform ! PerformPromiseThen(_valueWrapper_, _onFulfilled_, *undefined*, _promiseCapability_).
+          1. If _closeIteratorOnRejection_ is *false*, then
+            1. Let _onRejected_ be *undefined*.
+          1. Else,
+            1. Let _closeIterator_ be a new Abstract Closure with parameters (_error_) that captures _syncIteratorRecord_ and performs the following steps when called:
+              1. Return ? IteratorClose(_syncIteratorRecord_, ThrowCompletion(_error_)).
+            1. Let _onRejected_ be ! CreateBuiltinFunction(_closeIterator_, 1, *""*, &laquo; &raquo;).
+            1. NOTE: _onRejected_ is used to close the Iterator when the *"value"* property of an IteratorResult object it yields is a rejected promise.
+          1. Perform ! PerformPromiseThen(_valueWrapper_, _onFulfilled_, _onRejected_, _promiseCapability_).
           1. Return _promiseCapability_.[[Promise]].
         </emu-alg>
       </emu-clause>