new file mode 100644
--- /dev/null
+++ b/layout/forms/crashtests/478219-1.xhtml
@@ -0,0 +1,7 @@
+<html xmlns="http://www.w3.org/1999/xhtml" xmlns:mathml="http://www.w3.org/1998/Math/MathML" xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+<div>
+<xul:textbox onDOMAttrModified="this.parentNode.removeChild(this)">
+<mathml:mathml/>
+</xul:textbox>
+</div>
+</html>
--- a/layout/forms/crashtests/crashtests.list
+++ b/layout/forms/crashtests/crashtests.list
@@ -26,8 +26,9 @@ load 388374-1.xhtml
load 388374-2.html
load 393656-1.xhtml
load 393656-2.xhtml
load 404118-1.html
load 404123-1.html
load 455451-1.html
load 457537-1.html
load 457537-2.html
+load 478219-1.xhtml
