1024085 - Developer tools sends extra requests for CSS with no-cache headers

Status: UNCONFIRMED

(DevTools :: Style Editor, defect, P3)

Description

[dgsan]

Attachment: extra-requests-1.png

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:30.0) Gecko/20100101 Firefox/30.0 (Beta/Release)
Build ID: 20140608211457

Steps to reproduce:

Doesn't seem to happen on every site, but happens on some sites. As an example of a site that exhibits the behaviour, look at Newegg.com. 

Open the developer tools request tab and visit the site.

Further information will be in the 'What happened?' section.


Actual results:

You will notice that newegg.v1.w.10393.1.css (or whatever the first CSS file is named) is the first file requested in the requests tab of developer tools. Then scroll down to near the bottom and you will see that at some point (likely after page load/ready) newegg.v1.w.10393.1.css (the same css file as the first file) is requested an additional five times, this time with no-cache headers each time.

Other websites I've encountered exhbiting this issue don't always request the CSS over with no-cache headers the same number of times. Generally the number of extra requests, if they happen, ranges from 3 to 6.

On my own server I've examined server logs with and without developer tools open and I can confirm that the extra requests are only sent with developer tools open. When they're closed it sends one request as expected. Likewise, the problem occurs even with extensions disabled. Also not replicable in Chrome.




Expected results:

The first CSS file should be requested only once.

Comment 1

[Patrick Brosset <:pbro>]

Inspector bug triage (filter on CLIMBING SHOES).