Julien Wajsberg [:julienw] Reporter
	Description • 8 years ago

STR:
0. Set "dom.ipc.processCount" to 8 in about:config.
1. Open a page.
2. press CTRL-U or right click + "view the code source" (not sure of the real title as I use a french-localized Firefox)
=> very often the opened tab is blank.

	:Gijs (he/him)
	Comment 1 • 8 years ago

You're sure this only happens with the processCount increased? If so, I guess this should block bug 1207306, but equally I have no idea why that would make view source unreliable...

	Julien Wajsberg [:julienw] Reporter
	Comment 2 • 8 years ago

I'm not _so_ sure but I think this was happening quite often (maybe 7/8) when I added this, and never when I removed it.

So when the opened tab is blank (I mean when the issue happens) there is also nothing in the address bar (with the "Search or enter address" placeholder), a "New tab" title, pretty much like the result of opening a new tab with a blank page. So no "view-source:" URL. That's why I filed this in Firefox as I'm not sure this is really an issue in the core view-source functionality, but rather in the code that opens a tab to this.

	:Gijs (he/him)
	Comment 3 • 8 years ago

(In reply to Julien Wajsberg [:julienw] from comment #2)
> I'm not _so_ sure but I think this was happening quite often (maybe 7/8)
> when I added this, and never when I removed it.
> 
> So when the opened tab is blank (I mean when the issue happens) there is
> also nothing in the address bar (with the "Search or enter address"
> placeholder), a "New tab" title, pretty much like the result of opening a
> new tab with a blank page. So no "view-source:" URL. That's why I filed this
> in Firefox as I'm not sure this is really an issue in the core view-source
> functionality, but rather in the code that opens a tab to this.

I just tried to reproduce. When this happens this shows up in the error console:

TypeError: contentWindow is null viewSource-content.js:227:11


Which is this code:

https://dxr.mozilla.org/mozilla-central/source/toolkit/components/viewsource/content/viewSource-content.js#222-227

which presumably fails because the window isn't in the process that receives the message, if the frame script is inserted into multiple processes and all of them get the message. So I think this bug should probably stay in Toolkit/View Source for now. :-)

While it doesn't seem like it at the surface, I do wonder if this is at all related to bug 1172165 which I landed on Sunday. Julien, do you know if this is a recent regression?

	:Gijs (he/him)
	Comment 4 • 8 years ago

(In reply to :Gijs Kruitbosch from comment #3)
> While it doesn't seem like it at the surface, I do wonder if this is at all
> related to bug 1172165 which I landed on Sunday. Julien, do you know if this
> is a recent regression?

Elaborating a little... the changes to how view-source is no longer same-origin / linkable with its own nested URI might mean that we now make different decisions about whether it should be in the same process as the URL it is the view-source URL of.

Or maybe it's just coincidence that this got filed right after I landed those patches. I'm not sure! :-)

	:Gijs (he/him)
	Comment 6 • 8 years ago

Well, that solves that mystery. Thanks!

	Julien Wajsberg [:julienw] Reporter
	Comment 7 • 8 years ago

Yeah it happens to me for quite a long time. I still reproduce in the Nightly Build 20160201030241, is your patch in this build ?

	:Gijs (he/him)
	Comment 9 • 8 years ago

(In reply to Julien Wajsberg [:julienw] from comment #7)
> Yeah it happens to me for quite a long time. I still reproduce in the
> Nightly Build 20160201030241, is your patch in this build ?

Yes. It didn't intend to fix this, I was worried I caused the breakage, but clearly that's not the case because the breakage predates my patch.