1110523 - Files being downloaded twice when proxy enabled

Status: UNCONFIRMED

(Core :: Networking: Proxy, defect, P3)

Description

[Ray Satiro]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:37.0) Gecko/20100101 Firefox/37.0
Build ID: 20141209030205

Steps to reproduce:

I'm downloading the latest version of Python for Windows in Nightly.

Enable a debugging proxy or some monitor. I use:

Fiddler Web Debugger (v4.4.9.7)
Built: Tuesday, November 25, 2014

Go to https://www.python.org/downloads/release/python-279/
Right-click on x86 and/or x64 msi installer, Save link as.

You might have to repeat a few times.


Actual results:

Sometimes files are downloaded twice. I can see in Fiddler debugging proxy often two sessions are made from Nightly both requesting the same file. This results in two concurrent downloads, although nothing in the GUI shows that.


Expected results:

When I download a file it should not be retrieved from the server twice.

Comment 1

[Matthias Versen [:Matti]]

Are you sure that 2 files are really downloaded ?
It's normal that Firefox tries to open 2 connections but one of them will be closed immediately.

Comment 2

[Ray Satiro]

(In reply to Matthias Versen [:Matti] from comment #1)
> Are you sure that 2 files are really downloaded ?
> It's normal that Firefox tries to open 2 connections but one of them will be
> closed immediately.

Yes. It may have something to do with how Firefox interacts with the debugging proxy. I checked in Wireshark and I can't reproduce unless I have the proxy is enabled. Can you change the title to 'Files being downloaded twice when proxy enabled'

Comment 3

[Firefox Bug Husbandry Bot]

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258

Comment 4

[Firefox Bug Husbandry Bot]

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258

Comment 5

[BMO Automation]

Moving bug to Core/Networking: Proxy.