1347761 - Inspector goes blank when start downloading a file

Status: RESOLVED DUPLICATE of bug 1793685

(DevTools :: Inspector, defect, P3)

Description

[684sigma]

I have a problem with Firefox Beta 53, Firefox Nightly 55. It doesn't happen in Firefox ESR 45.
Sometimes when I download files, all text in inspector disappears.
I noticed one specific scenario when it happens

1. Open https://bugzilla.mozilla.org/show_bug.cgi?id=1347370
2. Open Devtools -> Inspector, add "download" attribute to any link on the page
3. Click that link

Result: All text in inspector disappears
Expected: Text in inspector should be visible without reopening devtools

Comment 1

[Loic]

Reg range:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=a105cf2d33a5643d63c516d5ecfe917d8eb5eeee&tochange=fb4f5c7e082a4176cd1b8f3c784e5f424417e3fa

Alexandre Poirot — Bug 1151909 - Make the inspector actor wait for DOMContentLoaded instead of load. r=pbro

Comment 2

[Patrick Brosset <:pbro>]

Inspector bug triage (filter on CLIMBING SHOES).

Comment 8

[pnparam]

It seems this issue reported two years back and not resolved yet on both of my Firefox - Quantum 64.0.2 (64-bit) and Developer Edition 66.0b2 (64-bit) . It will be nice if we get a fix for this problem.

Comment 9

[Mike Ratcliffe [:miker] [:mratcliffe] [:mikeratcliffe]]

Attachment: test.html

Comment 10

[Mike Ratcliffe [:miker] [:mratcliffe] [:mikeratcliffe]]

STR

1. Open this test.
2. Open the Inspector.
3. Click the link.

Actual

The markup view goes blank.

Expected

The markup view does not go blank.

Comment 11

[Mike Ratcliffe [:miker] [:mratcliffe] [:mikeratcliffe]]

@bz Sorry to bug you!

In DevTools we use a nsIWebProgress listener to detect new pageloads (onDOMContentLoaded etc. are all way too late):

webProgress.addProgressListener(this,
                                Ci.nsIWebProgress.NOTIFY_STATE_WINDOW |
                                Ci.nsIWebProgress.NOTIFY_STATE_DOCUMENT);

The onStateChange handler is here:
https://searchfox.org/mozilla-central/source/devtools/server/actors/targets/browsing-context.js#1628

The problem is that if we have a download link e.g. <a href="image.png" download=""> and somebody clicks on it then this is picked up by the web progress listener and we tear down the markup view ready to set it up for the new document.

How can we detect from within onStateChange() that this is a download so that we can ignore the event?

Comment 12

[Boris Zbarsky [:bzbarsky]]

Sorry for the lag here... I'm not sure how this fell through the cracks.

So it sounds like right now the devtools code is listening STATE_START|STATE_IS_DOCUMENT or something? That gets fired when we first send a request to the server.

We don't know whether it's a download or not until we receive a response from the server. The server may respond with a MIME type we don't know how to handle, or with "Content-disposition: attachment", and those would be downloads. Or the server can respond with a cross-origin redirect and that will not be a download, even if the "download" attribute is present. Or the server can respond with an HTTP 204 and that will be neither a download nor a navigation.

Presumably what you really want to know is "we're about to navigate away from this document" and switch to a different document, which will happen after we get the server response.

Does the pagehide event do what you want? If not, why not?

Comment 13

[Mike Ratcliffe [:miker] [:mratcliffe] [:mikeratcliffe]]

We should be able to make use of the pagehide event for this.

Comment 15

[BugBot [:suhaib / :marco/ :calixte]]

The severity field for this bug is relatively low, S3. However, the bug has 6 duplicates.
:jdescottes, could you consider increasing the bug severity?

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