From ec081a2ef51fceecceec0250faa3dc7e56f24612 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sun, 3 Dec 2023 23:24:48 +0100
Subject: [PATCH] LibWeb: Don't crash on FormData.append() with emoji in name

If you can believe it, we were once again using StringBuilder's append()
when we really wanted append_code_point().
---
 .../expected/HTML/FormData-append-with-emoji-in-name.txt | 1 +
 .../input/HTML/FormData-append-with-emoji-in-name.html   | 9 +++++++++
 Userland/Libraries/LibWeb/Infra/Strings.cpp              | 2 +-
 3 files changed, 11 insertions(+), 1 deletion(-)
 create mode 100644 Tests/LibWeb/Text/expected/HTML/FormData-append-with-emoji-in-name.txt
 create mode 100644 Tests/LibWeb/Text/input/HTML/FormData-append-with-emoji-in-name.html

diff --git a/Tests/LibWeb/Text/expected/HTML/FormData-append-with-emoji-in-name.txt b/Tests/LibWeb/Text/expected/HTML/FormData-append-with-emoji-in-name.txt
new file mode 100644
index 0000000000..5db64a560d
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/HTML/FormData-append-with-emoji-in-name.txt
@@ -0,0 +1 @@
+   PASS (Didn't crash)
diff --git a/Tests/LibWeb/Text/input/HTML/FormData-append-with-emoji-in-name.html b/Tests/LibWeb/Text/input/HTML/FormData-append-with-emoji-in-name.html
new file mode 100644
index 0000000000..e0bfb210bc
--- /dev/null
+++ b/Tests/LibWeb/Text/input/HTML/FormData-append-with-emoji-in-name.html
@@ -0,0 +1,9 @@
+<div id=test></div>
+<script src="../include.js"></script>
+<script>
+    test(() => {
+        const formData = new FormData();
+        formData.append("🧐", "");
+        println("PASS (Didn't crash)");
+    });
+</script>
diff --git a/Userland/Libraries/LibWeb/Infra/Strings.cpp b/Userland/Libraries/LibWeb/Infra/Strings.cpp
index e71fedeaba..233313c8b0 100644
--- a/Userland/Libraries/LibWeb/Infra/Strings.cpp
+++ b/Userland/Libraries/LibWeb/Infra/Strings.cpp
@@ -85,7 +85,7 @@ ErrorOr<String> convert_to_scalar_value_string(StringView string)
     for (u32 code_point : utf8_view) {
         if (is_unicode_surrogate(code_point))
             code_point = 0xFFFD;
-        TRY(scalar_value_builder.try_append(code_point));
+        scalar_value_builder.append_code_point(code_point);
     }
     return scalar_value_builder.to_string();
 }