1333914 - View source sometimes fails to open with multiple RDM tabs

Status: VERIFIED FIXED

(DevTools :: Responsive Design Mode, defect, P3)

Description

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

Copied from bug 1331601 comment 26 by John O:

Steps to reproduce:
1) Open 2 different webpages in 2 tabs
2) Put each tab into RDM
3) View source on Tab1
4) View source on Tab2

Expected behaviour:
3) Tab1 page source displayed
4) Tab2 page source displayed

Actual behaviour:
3) Tab1 page source IS displayed
4) Blank page is displayed

Other notes
After exiting RDM in Tab2, view source does work.
Going back to Tab1 (still in RDM). View source then does not work (blank page displayed)

Comment 1

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

In my local testing, I _sometimes_ see the source for tab 2.  Looking more closely, it seems related to the use of multiple content processes in Nightly 54.

For me, the default value in about:config for "dom.ipc.processCount" is 2.  If I change this to 1, restart Firefox, then view source works every time.

John O, is this the same thing you see?

Comment 2

[u424271]

I also have "dom.ipc.processCount"=2

After setting it to 1, view source seems to work every time for me too

Comment 3

[Simona Badau, Desktop QA]

Mozilla/5.0 (Windows NT 10.0; WOW64; rv:54.0) Gecko/20100101 Firefox/54.0
Build ID: 20170127030206

I'm also seeing a blank view source page but when following a more simplified scenario.

STR:
1. Open one page
2. Put the page into RDM (CTRL+Shift+M) and leave it like this
3. View the source by clicking CTRL+U

Expected results:
The view source is opened in a new tab

Actual results:
The view source page is empty.

Comment 4

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

(In reply to Simona B [:simonab ] from comment #3)
> Mozilla/5.0 (Windows NT 10.0; WOW64; rv:54.0) Gecko/20100101 Firefox/54.0
> Build ID: 20170127030206
> 
> I'm also seeing a blank view source page but when following a more
> simplified scenario.
> 
> STR:
> 1. Open one page
> 2. Put the page into RDM (CTRL+Shift+M) and leave it like this
> 3. View the source by clicking CTRL+U
> 
> Expected results:
> The view source is opened in a new tab
> 
> Actual results:
> The view source page is empty.

Simona, does this issue also go away if you change dom.ipc.processCount to 1 as mentioned in comment 1?  (Just want to make sure it's the same issue.)

Comment 5

[Simona Badau, Desktop QA]

Yes, if I set dom.ipc.processCount to 1, the issue goes away.

Comment 6

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

The changes in bug 1335281 should fix this RDM issue as well.

Comment 7

[Simona Badau, Desktop QA]

(In reply to J. Ryan Stinnett [:jryans] (use ni?) from comment #6)
> The changes in bug 1335281 should fix this RDM issue as well.

I reproduced the initial issue mentioned in the Description and in Comment 3 on Nightly 54.0a1 (build ID: 20170125030214).

Verified as fixed using the latest Nightly 54.0a1 (Build ID: 20170125030214) on Windows 10 x64, Ubuntu 16.04 x64 and Mac OS X 10.11.