fix: LiveQuery matcher crashes when a pointer or typed field value is null

spec/QueryTools.spec.js

@@ -777,6 +777,28 @@ describe('matchesQuery', function () {
     expect(matchesQuery(message, q)).toBe(false);
   });
 
+  it('does not match or crash when a pointer field is null (#7929)', () => {
+    // Parse Dashboard stores a cleared pointer as null rather than unsetting it.
+    const message = {
+      id: new Id('Message', 'O1'),
+      profile: null,
+    };
+    const q = new Parse.Query('Message');
+    q.equalTo('profile', Parse.Object.fromJSON({ className: 'Profile', objectId: 'abc' }));
+    expect(matchesQuery(message, q)).toBe(false);
+  });
+
+  it('does not match or crash when a typed field is null (#7929)', () => {
+    // Same null-field scenario against a non-pointer typed constraint (goes through equalObjects).
+    const obj = {
+      id: new Id('Person', 'O1'),
+      birthday: null,
+    };
+    const q = new Parse.Query('Person');
+    q.equalTo('birthday', new Date(1990, 1));
+    expect(matchesQuery(obj, q)).toBe(false);
+  });
+
   it('should support containedIn with array of pointers', () => {
     const message = {
       id: new Id('Message', 'O2'),

src/LiveQuery/QueryTools.js

@@ -264,8 +264,10 @@ function matchesKeyConstraints(object, key, constraints) {
   if (constraints.__type) {
     if (constraints.__type === 'Pointer') {
       return equalObjectsGeneric(object[key], constraints, function (obj, ptr) {
+        // A cleared pointer can be stored as null (e.g. via Parse Dashboard), guard it (#7929)
         return (
           typeof obj !== 'undefined' &&
+          obj !== null &&
           ptr.className === obj.className &&
           ptr.objectId === obj.objectId
         );

src/LiveQuery/equalObjects.js

@@ -14,6 +14,10 @@ function equalObjects(a, b) {
   if (a === b) {
     return true;
   }
+  // typeof null is 'object', so guard before dereferencing either side (#7929)
+  if (a === null || b === null) {
+    return a === b;
+  }
   if (toString.call(a) === '[object Date]') {
     if (toString.call(b) === '[object Date]') {
       return +a === +b;