Fix crash in JS_NewSymbol when description is NULL

Author: engsr6982

quickjs.c

@@ -3404,6 +3404,15 @@ static JSValue JS_NewSymbolFromAtom(JSContext *ctx, JSAtom descr,
 /* `description` may be pure ASCII or UTF-8 encoded */
 JSValue JS_NewSymbol(JSContext *ctx, const char *description, bool is_global)
 {
+    if (description == NULL) {
+        if (!is_global) {
+            /* Local symbol without description: Symbol() */
+            return JS_NewSymbolInternal(ctx, NULL, JS_ATOM_TYPE_SYMBOL);
+        }
+        /* Global symbol without description: Symbol.for() 
+           Per ES spec, ToString(undefined) becomes "undefined" */
+        description = "undefined";    
+    }
     JSAtom atom = JS_NewAtom(ctx, description);
     if (atom == JS_ATOM_NULL)
         return JS_EXCEPTION;