From 777a93918fa17d337bb6224d0a5f325747382d7b Mon Sep 17 00:00:00 2001
From: Linus Groh <mail@linusgroh.de>
Date: Sun, 4 Jul 2021 17:59:07 +0100
Subject: [PATCH] LibJS: Handle invalid and symbol PropertyName in its
 AK::Formatter

This would previously crash as we used to_string() without checking the
type first. Circumvent that by handling invalid and numeric ones
separately and then using to_string_or_symbol().
---
 Userland/Libraries/LibJS/Runtime/PropertyName.h | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/Userland/Libraries/LibJS/Runtime/PropertyName.h b/Userland/Libraries/LibJS/Runtime/PropertyName.h
index 107b6098ea..8df48475ad 100644
--- a/Userland/Libraries/LibJS/Runtime/PropertyName.h
+++ b/Userland/Libraries/LibJS/Runtime/PropertyName.h
@@ -230,9 +230,14 @@ namespace AK {
 
 template<>
 struct Formatter<JS::PropertyName> : Formatter<StringView> {
-    void format(FormatBuilder& builder, JS::PropertyName const& value)
+    void format(FormatBuilder& builder, JS::PropertyName const& property_name)
     {
-        Formatter<StringView>::format(builder, value.to_string());
+        if (!property_name.is_valid())
+            Formatter<StringView>::format(builder, "<invalid PropertyName>");
+        else if (property_name.is_number())
+            Formatter<StringView>::format(builder, String::number(property_name.as_number()));
+        else
+            Formatter<StringView>::format(builder, property_name.to_string_or_symbol().to_display_string());
     }
 };