/* Any copyright is dedicated to the Public Domain.
   http://creativecommons.org/publicdomain/zero/1.0/ */

const URL =
  "http://mochi.test:8888/browser/toolkit/components/thumbnails/" +
  "test/background_red_scroll.html";

function isRedThumbnailFuzz(r, g, b, expectedR, expectedB, expectedG, aFuzz) {
  return (
    Math.abs(r - expectedR) <= aFuzz &&
    Math.abs(g - expectedG) <= aFuzz &&
    Math.abs(b - expectedB) <= aFuzz
  );
}

// Test for black borders caused by scrollbars.
add_task(async function thumbnails_bg_bug727765() {
  // Create a tab with a page with a red background and scrollbars.
  await BrowserTestUtils.withNewTab(
    {
      gBrowser,
      url: URL,
    },
    async () => {
      await captureAndCheckColor(255, 0, 0, "we have a red thumbnail");

      // Check the thumbnail color of the bottom right pixel.
      await whenFileExists(URL);

      let data = await retrieveImageDataForURL(URL);
      let [r, g, b] = [].slice.call(data, -4);
      let fuzz = 2; // Windows 8 x64 blends with the scrollbar a bit.
      var message =
        "Expected red thumbnail rgb(255, 0, 0), got " + r + "," + g + "," + b;
      ok(isRedThumbnailFuzz(r, g, b, 255, 0, 0, fuzz), message);
    }
  );
});