assert,util: fix stale nested cycle memo entries

Temporary nested cycle-tracking entries could remain in the memory set
after a successful comparison. If a later sibling comparison reused one
of those objects, deepStrictEqual could incorrectly fail for equivalent
structures.
This cleans up the temporary nested entries after the nested
comparison returns.
Fixes: #62422
PR-URL: #62509Fixes: #62422
Reviewed-By: Jordan Harband <ljharb@gmail.com>

Author: BridgeAR

lib/internal/util/comparisons.js

@@ -520,6 +520,10 @@ function handleCycles(val1, val2, mode, keys1, keys2, memos, iterationType) {
 memos.deep=true;
 constresult=objEquiv(val1,val2,mode,keys1,keys2,memos,iterationType);
 memos.deep=false;
+if(memos.set!==undefined){
+memos.set.delete(memos.c);
+memos.set.delete(memos.d);
+}
 returnresult;
 }
 memos.set=newSafeSet();

test/parallel/test-assert-deep.js

@@ -248,6 +248,14 @@ function assertOnlyDeepEqual(a, b, err) {
 );
 }
 
+functionactivateMemoizedCycleDetection(){
+constcircA={};
+circA.self=circA;
+constcircB={};
+circB.self=circB;
+assert.deepStrictEqual(circA,circB);
+}
+
 test('es6 Maps and Sets',()=>{
 assertDeepAndStrictEqual(newSet(),newSet());
 assertDeepAndStrictEqual(newMap(),newMap());
@@ -597,6 +605,36 @@ test('GH-14441. Circular structures should be consistent', () => {
 }
 });
 
+test('deepStrictEqual handles shared expected array elements after cycle detection',()=>{
+constsharedExpected={outer: {inner: 0}};
+constactualValues=[{outer: {inner: 0}},{outer: {inner: 0}}];
+constexpectedValues=[sharedExpected,sharedExpected];
+
+activateMemoizedCycleDetection();
+
+assertDeepAndStrictEqual(actualValues[0],expectedValues[0]);
+assertDeepAndStrictEqual(actualValues[1],expectedValues[1]);
+assertDeepAndStrictEqual(actualValues,expectedValues);
+});
+
+test('deepStrictEqual handles cross-root aliases after cycle detection',()=>{
+activateMemoizedCycleDetection();
+
+constnestedExpected={};
+nestedExpected.loop=nestedExpected;
+nestedExpected.payload={value: 1};
+
+constexpected={};
+expected.loop=nestedExpected;
+expected.payload={value: 1};
+
+constactual={};
+actual.loop=expected;
+actual.payload={value: 1};
+
+assertDeepAndStrictEqual(actual,expected);
+});
+
 // https://github.com/nodejs/node-v0.x-archive/pull/7178
 test('Ensure reflexivity of deepEqual with `arguments` objects.',()=>{
 constargs=(function(){returnarguments;})();