1 files changed, 21 insertions, 0 deletions
diff --git a/layout/base/tests/interlinePosition-after-Selection-addRange.html b/layout/base/tests/interlinePosition-after-Selection-addRange.html
new file mode 100644
index 0000000000..8e45277249
--- /dev/null
+++ b/layout/base/tests/interlinePosition-after-Selection-addRange.html
@@ -0,0 +1,21 @@
+<!doctype html>
+<html class="reftest-wait">
+<meta charset="utf-8">
+<title>Selection.addRange() should always reset interline position</title>
+<script src="/tests/SimpleTest/SimpleTest.js"></script>
+<style>
+  div[contenteditable] {
+    padding: 1em;
+  }
+</style>
+<script>
+SimpleTest.waitForFocus(async () => {
+  const editingHost = document.querySelector("div[contenteditable]");
+  editingHost.focus();
+  getSelection().collapse(editingHost, 2);
+  SpecialPowers.wrap(getSelection()).interlinePosition = false;
+  getSelection().addRange(getSelection().getRangeAt(0));
+  document.documentElement.removeAttribute("class");
+});
+</script>
+<div contenteditable="true" spellcheck="false">abc<br><br></div>