diff --git a/layout/generic/crashtests/812879-2.html b/layout/generic/crashtests/812879-2.html
new file mode 100644
index 00000000000..10323296e08
--- /dev/null
+++ b/layout/generic/crashtests/812879-2.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<html>
+<head>
+<script>
+
+function boom()
+{
+  var table = document.createElement("table");
+  var tbody = document.createElement("tbody");
+  var td = document.createElement("td");
+  tbody.appendChild(td);
+  table.appendChild(tbody);
+  document.body.appendChild(table);
+  td.style.marginTop = "126102421%";
+  td.style.marginLeft = "126102421%";
+  td.style.cssFloat = "right";
+  td.style.pageBreakInside = "avoid";
+
+  document.documentElement.offsetHeight;
+
+  tbody.style.overflowX = "hidden";
+
+  document.documentElement.offsetHeight;
+
+  document.body.style.MozColumns = "auto";
+  tbody.style.color = "red";
+
+  document.documentElement.offsetHeight;
+}
+
+</script>
+</head>
+
+<body onload="boom();"></body>
+</html>
diff --git a/layout/generic/crashtests/812879.html b/layout/generic/crashtests/812879.html
new file mode 100644
index 00000000000..67a0ac70c95
--- /dev/null
+++ b/layout/generic/crashtests/812879.html
@@ -0,0 +1,6 @@
+<!DOCTYPE html>
+<html>
+<body onload="document.getElementById('x').style.overflowX = 'hidden';">
+<table><tbody id="x"><tr><td style="margin-top: 126102421%; margin-right: 126102421%; float: right; page-break-inside: avoid;"></td></tr></tbody></table>
+</body>
+</html>
diff --git a/layout/generic/crashtests/crashtests.list b/layout/generic/crashtests/crashtests.list
index 841e335ba93..4e2081b689a 100644
--- a/layout/generic/crashtests/crashtests.list
+++ b/layout/generic/crashtests/crashtests.list
@@ -494,6 +494,8 @@ load 804089-1.xhtml
 load 807565-1.html
 load 807565-2.html
 load 810726.html
+load 812879.html
+load 812879-2.html
 load 825810-1.html
 load 825810-2.html
 load 827076.html
