Note-css empty background image will cause the page to be loaded two times

If the page style background picture path is set to ' or ' # ', it will cause the page to be loaded repeatedly two times (chrome.56.0.2924.87 test)

Because: Empty picture Path property value, the URL of the current page is loaded by default as the picture path

Safari and Chrome make a request to the actual page itself.

Internet Explorer makes a request to the directory with which the page is located. --unsure of the rigor of this description, edge.25.10586.0 did not test the problem ~

--Citing articles from 2009, it may be that the browser has been repaired, but the first sentence is described in the same way as the current test results.

Example:

<style= "Background:url ()"></div>

Of these, the header files for two requests were:

1. HTML Request

accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8

2. Image request

accept:image/webp,image/*,*/*;q=0.8

The second request is HTML, but the script in the test page does not execute properly, possibly: (reason for guessing ~)

Because it isn't in a supported image format, so the rest of the response is thrown away.

Other tests: img.src= ' did not cause problems with multiple loads.

Conclusion:

Make sure that the picture path in the page is formatted in the correct format.

Reference:

https://bugzilla.mozilla.org/show_bug.cgi?id=473528

https://github.com/woocommerce/storefront/issues/394

http://icanhascode.com/2008/06/the-mystery-of-the-multiple-requests/

https://lifesinger.wordpress.com/2011/09/22/empty-src-is-dangerous/

https://www.nczonline.net/blog/2009/11/30/empty-image-src-can-destroy-your-site/

https://www.w3.org/TR/css3-background/#the-background-image

Note-css empty background image will cause the page to be loaded two times