1 files changed, 38 insertions, 0 deletions
diff --git a/layout/base/tests/bug1896051.html b/layout/base/tests/bug1896051.html
new file mode 100644
index 0000000000..ba35339475
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+++ b/layout/base/tests/bug1896051.html
@@ -0,0 +1,38 @@
+<!doctype html>
+<html class="reftest-wait">
+<script src="/tests/SimpleTest/EventUtils.js"></script>
+<script src="/tests/SimpleTest/SimpleTest.js"></script>
+<style>
+  textarea {
+    font: 13px / 1 monospace;
+    border: 1px solid;
+    padding: 0;
+    overflow: hidden;
+    resize: none;
+  }
+</style>
+<textarea rows=5>
+a
+b
+c
+d
+</textarea>
+<script>
+SimpleTest.waitForFocus(function() {
+  let textarea = document.querySelector("textarea");
+  textarea.focus();
+  if (navigator.platform.startsWith("Mac")) {
+    // On mac there is no page down key that moves the selection, afaict.
+    // (Fn+Arrow moves the scroll position but not selection).
+    // Do the next thing which would be something like Cmd+Down to move to the
+    // end. That tests a different code-path altogether, but for this test it
+    // doesn't matter.
+    synthesizeKey("KEY_ArrowDown", { metaKey: true });
+  } else {
+    synthesizeKey("KEY_PageDown");
+  }
+  setTimeout(() => {
+    document.documentElement.removeAttribute("class")
+  }, 0);
+});
+</script>