1 files changed, 48 insertions, 0 deletions
diff --git a/gfx/layers/apz/test/mochitest/helper_no_scalable_with_initial_scale.html b/gfx/layers/apz/test/mochitest/helper_no_scalable_with_initial_scale.html
new file mode 100644
index 0000000000..7280a26006
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+++ b/gfx/layers/apz/test/mochitest/helper_no_scalable_with_initial_scale.html
@@ -0,0 +1,48 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, minimum-scale=0.25, initial-scale=0.5, user-scalable=no">
+  <title>Tests that the layout viewport is not expanted to the minimum scale size if user-scalable=no is specified</title>
+  <script type="application/javascript" src="apz_test_utils.js"></script>
+  <script src="/tests/SimpleTest/paint_listener.js"></script>
+  <style>
+    html,body {
+      overflow: hidden;
+      margin: 0;
+    }
+    div {
+      position: absolute;
+    }
+  </style>
+</head>
+<body>
+  <div style="width: 400%; height: 400%; background: red;"></div>
+  <div style="width: 100%; height: 100%; background-color: blue"></div>
+  <script type="application/javascript">
+    const utils = SpecialPowers.getDOMWindowUtils(window);
+
+    async function test(testDriver) {
+      utils.scrollToVisual(100, 0, utils.UPDATE_TYPE_MAIN_THREAD,
+                           utils.SCROLL_MODE_INSTANT);
+
+      let receivedScrollEvent = false;
+      window.visualViewport.addEventListener("scroll", () => {
+        receivedScrollEvent = true;
+      }, { once: true });
+
+      await waitUntilApzStable();
+
+      // Waits two frames to get a chance to deliver scroll events.
+      await promiseFrame();
+      await promiseFrame();
+
+      ok(!receivedScrollEvent, "Scroll should never happen");
+      is(visualViewport.offsetLeft, 0,
+         "The visual viewport offset should not be moved");
+    }
+
+    waitUntilApzStable().then(test).then(subtestDone, subtestFailed);
+  </script>
+</body>
+</html>