diff --git a/src/test/html/longcat.html b/src/test/html/longcat.html
new file mode 100644
index 00000000000..53e13c3fcee
--- /dev/null
+++ b/src/test/html/longcat.html
@@ -0,0 +1,10 @@
+
+
+
+
+
+
+
+
+
+
diff --git a/src/test/html/longcat.js b/src/test/html/longcat.js
new file mode 100644
index 00000000000..d492c3417c4
--- /dev/null
+++ b/src/test/html/longcat.js
@@ -0,0 +1,23 @@
+var longcats = window.document.getElementsByTagName("img");
+var longcat_top = longcats[0];
+var longcat_mid = longcats[1];
+var longcat_bot = longcats[2];
+
+function wait_for_img_load(f) {
+ if (longcat_top.width != 0 && longcat_mid.width != 0 && longcat_bot.width != 0) {
+ f();
+ } else {
+ window.setTimeout(function() { wait_for_img_load(f) }, 1);
+ }
+}
+
+wait_for_img_load(function() {
+ var count = 0;
+ function elongate() {
+ let height = Math.round((Math.sin(count) + 1) * 70 + 20);
+ count += 0.2;
+ longcat_mid.height = height;
+ window.setTimeout(function() { elongate() }, 100);
+ }
+ elongate();
+});
diff --git a/src/test/html/longcatbot.png b/src/test/html/longcatbot.png
new file mode 100644
index 00000000000..10b897e88a8
Binary files /dev/null and b/src/test/html/longcatbot.png differ
diff --git a/src/test/html/longcatmid.png b/src/test/html/longcatmid.png
new file mode 100644
index 00000000000..bd9a921ac64
Binary files /dev/null and b/src/test/html/longcatmid.png differ
diff --git a/src/test/html/longcattop.png b/src/test/html/longcattop.png
new file mode 100644
index 00000000000..beb85663d3a
Binary files /dev/null and b/src/test/html/longcattop.png differ