css/css-pseudo/active-selection-045.html

<!DOCTYPE html>

<html class="reftest-wait">

  <meta charset="UTF-8">

  <title>CSS Pseudo-Elements Test: active selection and image</title>

  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
  <link rel="help" href="https://www.w3.org/TR/css-pseudo-4/#highlight-painting">
  <link rel="match" href="../reference/ref-nothing-below.xht">

  <meta name="assert" content="This test checks that the associated overlay for image must not cover (or leak) outside the image's content box.">

  <style>
  /*
  Chromium 80+ highlights the
  top of line box minus
  content box and the bottom
  of line box minus content
  box.
  Firefox 72+ consistently highlights
  only the image content box itself.
  */

  div
    {
      font-size: 300px;
    }

  img::selection
    {
      background-color: red;
    }

  span#masking
    {
      background-color: white;
      display: inline-block;
      height: 100px;
      position: relative;
      right: 100px;
      width: 100px;
    }
  </style>

  <script>
  function startTest()
  {
  var targetRange = document.createRange();
  /* We first create an empty range */
  targetRange.selectNodeContents(document.getElementById("test"));
  /* Then we set the range boundaries to the children of div#test */
  window.getSelection().addRange(targetRange);
  /* Finally, we now select such range of content */
  document.documentElement.className = "";
  }
  </script>

  <body onload="startTest();">

  <p>Test passes if there is nothing below.

  <div id="test"><img src="support/100x100-red.png" alt="Image download support must be enabled"><span id="masking"></span></div>