1401511 - WebExtension's proxy API mutates the array return value of FindProxyForURL

Status: RESOLVED FIXED

(WebExtensions :: Request Handling, defect, P1)

Description

[Rustam]

Attachment: FF 57 New proxy syntax.zip

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.91 Safari/537.36

Steps to reproduce:

I used this attached example


Actual results:

It gives many proxy errors.

If I will comment this line:
let allow = [{"host":"149.255.154.4","type":"proxy","port":8080}];

and will change this line 

return allow;

to

return [{"host":"149.255.154.4","type":"proxy","port":8080}]; 

all is working


Expected results:

This example must work

Comment 1

[Rustam]

Win 7 x64. 57.0a1 (2017-09-19) (64-bit)

Comment 2

[Rob Wu [:robwu]]

I see:
Proxy error: FindProxyForURL: Return type must be a string or array of objects

I debugged as follows:
0. Unzip the attached extension, start Firefox 57 with an empty profile, load the directory with the unzipped files.
1. Enable debugging via about:debugging
2. Launch the browser toolbox (Ctrl-Alt-Shift-I).
3. Search in the Debugger for ProxyScriptContext.jsm, and put a breakpoint at the line that emits the above error.
4. Trigger a request, e.g. by starting to type in the location bar.
5. Observe that the input "proxyData" is an empty array.
6. Walk up the stack trace, go to the applyFilter function and put a breakpoint at the ret = this.FindProxyForURL line.
7. Trigger a request.
8. Observe that the breakpoint is triggered, and that the "allowed" array from the provided sample extension is empty.

Mutated by:
https://searchfox.org/mozilla-central/rev/d08b24e613cac8c9c5a4131452459241010701e0/toolkit/components/extensions/ProxyScriptContext.jsm#132

Comment 3

[Rob Wu [:robwu]]

Attachment: Bug 1401511 - Don't mutate return value of FindProxyForURL

Review commit: https://reviewboard.mozilla.org/r/181750/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/181750/

Comment 4

[Shane Caraveo (:mixedpuppy)]

Comment on attachment 8910254 [details]
Bug 1401511 - Don't mutate return value of FindProxyForURL

https://reviewboard.mozilla.org/r/181750/#review187152

ah, that's why I originaly had a .sice() in the initial call to createProxyInfoFromData, but I later removed it.  This will need to be in 57.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d0e11356fe9c
Don't mutate return value of FindProxyForURL r=mixedpuppy

Comment 6

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/d0e11356fe9c

Comment 7

[Victor Carciu]

Verified as fixed using Build identifier: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0 and I can see the differences after the fix was landed in 57(no proxy errors). Please see attached screenshots.

Please let me know if any other testing is needed.

Comment 8

[Victor Carciu]

Attachment: Postfix screenshot