jsvObjectIterator is now safe even if not called on something iterable

ChangeLog

@@ -36,6 +36,7 @@
             Fix debugging of switch statements (fix #2562)
             Network: enable parsing of 'https' URL and TLS flag even even TLS not built in (#2410)
             removeListener while executing events no longer stops subsequent listeners from executing (#2151)
+            jsvObjectIterator is now safe even if not called on something iterable
 
      2v24 : Bangle.js2: Add 'Bangle.touchRd()', 'Bangle.touchWr()'
             Bangle.js2: After Bangle.showTestScreen, put Bangle.js into a hard off state (not soft off)

src/jsvariterator.c

@@ -494,14 +494,14 @@ void jsvStringIteratorAppendString(JsvStringIterator *it, JsVar *str, size_t sta
 // --------------------------------------------------------------------------------------------
 
 void jsvObjectIteratorNew(JsvObjectIterator *it, JsVar *obj) {
-  assert(jsvIsArray(obj) || jsvIsObject(obj) || jsvIsFunction(obj) || jsvIsGetterOrSetter(obj));
-  it->var = jsvLockSafe(jsvGetFirstChild(obj));
+  assert(!obj || jsvHasChildren(obj));
+  it->var = jsvHasChildren(obj) ? jsvLockSafe(jsvGetFirstChild(obj)) : 0;
 }
 
 /// Clone the iterator
 void jsvObjectIteratorClone(JsvObjectIterator *dstit, JsvObjectIterator *it) {
   *dstit = *it;
-  if (dstit->var) jsvLockAgain(dstit->var);
+  jsvLockAgainSafe(dstit->var);
 }
 
 /// Move to next item