LibWeb: Fix dialog.requestClose() crash

lukewarlow · awesomekling · commit 62f4cebbee3c · 2025-02-04T12:22:25.000+01:00
The spec previously asserted that close watcher was not null.

This could lead to a crash in some situations,
so instead we skip to close the dialog.
diff --git a/Libraries/LibWeb/HTML/HTMLDialogElement.cpp b/Libraries/LibWeb/HTML/HTMLDialogElement.cpp
@@ -242,8 +242,11 @@ void HTMLDialogElement::request_close(Optional<String> return_value)
     // 1. If this does not have an open attribute, then return.
     if (!has_attribute(AttributeNames::open))
         return;
-    // 2. Assert: this's close watcher is not null.
-    VERIFY(m_close_watcher);
+    // ADHOC: 2. If this's close watcher is null, then close the dialog this with returnValue, and return. See https://github.com/whatwg/html/pull/10983
+    if (!m_close_watcher) {
+        close_the_dialog(move(return_value));
+        return;
+    }
     // 3. Set dialog's enable close watcher for requestClose() to true.
     // ADHOC: Implemented slightly differently to the spec, as the spec is unnecessarily complex.
     m_close_watcher->set_enabled(true);
diff --git a/Tests/LibWeb/Crash/wpt-import/html/semantics/interactive-elements/the-dialog-element/dialog-requestclose-crash.html b/Tests/LibWeb/Crash/wpt-import/html/semantics/interactive-elements/the-dialog-element/dialog-requestclose-crash.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+
+<!-- This test passes if it does not crash. -->
+
+<dialog id="dialog" open>Dialog</dialog>
+
+<script>
+    window.onload = () => {
+        dialog.requestClose();
+    }
+</script>
