1 files changed, 30 insertions, 0 deletions
diff --git a/toolkit/components/printing/tests/file_window_print.html b/toolkit/components/printing/tests/file_window_print.html
new file mode 100644
index 0000000000..7a05cf4511
--- /dev/null
+++ b/toolkit/components/printing/tests/file_window_print.html
@@ -0,0 +1,30 @@
+<!doctype html>
+<meta charset="utf-8">
+<div id="before-print">Before print</div>
+<canvas id="canvas" width="100" height="100"></canvas>
+<script>
+  onload = function() {
+    // window.print() is special until after the load event is finished firing.
+    setTimeout(function() {
+      // This fires a timer which would trigger a navigation and prevent the
+      // test from completing if it happens during window.print().
+      let meta = document.createElement("meta");
+      meta.setAttribute("http-equiv", "refresh");
+      meta.setAttribute("content", "0; url=/unlikely-to-be-found");
+      document.head.appendChild(meta);
+      // This one should block until we're done printing, and block the
+      // navigation too.
+      window.print();
+      meta.remove();
+      document.body.insertAdjacentHTML('beforeend', `<div id="after-first-print">After first print</div>`);
+
+      let canvas = document.getElementById("canvas");
+      canvas.mozPrintCallback = function() {};
+
+      // This one shouldn't, because the print callbacks need to run.
+      window.print();
+
+      document.body.insertAdjacentHTML('beforeend', `<div id="after-second-print">After second print</div>`);
+    }, 0);
+  }
+</script>