[webextension] "block element" produces only an empty window

[mapx]

Environment

Windows 10
FF 57.0b4 (64-bit)
ABP 2.99.0.1867beta
Easylist

How to reproduce

go to google page
click ABP icon, click "block element"
select whatever element on page

Observed behaviour

• an empty window opens - no filters are proposed
• I tried to close the window => I have to click twice to get it closed

Expected behaviour

..normal behaviour

Situation also reported by the users in forum.

It seems nobody tested a crucial feature.

Background

This is a timing issue, the initialization message is sent to the pop-up before it is ready.

[mapx]

Trying to close (clicking "Cancel" ) the empty window, I get (in the console)

Scripts may not close windows that were not opened by script. composer.js:64:2

Clicking the window "x" I get in the console (but however the window is then closed clicking twice):

Error: port.onDisconnect.hasListeners is not a function  undefined
Error: Could not establish connection. Receiving end does not exist.  undefined

[trev]

I can reproduce this issue in Nightly (58.0a1 2017-10-26 on Linux) but not on Firefox 56. It's not actually an empty window however, resizing it makes the content appear - seems to be a Firefox rendering bug. Also, clicking the Cancel button works correctly here.

[trev]

There is a browser error being reported which is likely the cause:

TypeError: invalid 'in' operand browser tabbrowser.xml:2437:1

[mapx]

as I said it happens in FF 57. No text in the window, "cancel" not working.

[abpbot]

A commit referencing this issue has landed:
​Issue 5817 - Make sure to send initialization message to the Block Element pop-up only after it is initialized

[mapx]

It was fixed for chrome but not for firefox (57 - on windows 10)

More: "Cancel" button does not work, I have to click "X" to close the window

[mapx]

pressing "Cancel" I get in console:

Scripts may not close windows that were not opened by script.

opening the window =>

TypeError: invalid 'in' operand browser[Learn More]  tabbrowser.xml:2426:1
	_insertBrowser chrome://browser/content/tabbrowser.xml:2426:1
	getRelatedElement chrome://browser/content/tabbrowser.xml:7146:11
	set_selectedIndex chrome://global/content/bindings/tabbox.xml:406:31
	tabs_XBL_Constructor chrome://global/content/bindings/tabbox.xml:275:13
	<anonymous> chrome://browser/content/tabbrowser.xml:46:9
	_updateNewTabVisibility chrome://browser/content/tabbrowser.xml:5828:15
	tabbrowser_XBL_Constructor chrome://browser/content/tabbrowser.xml:5885:11
NS_ERROR_NOT_INITIALIZED: Component returned failure code: 0xc1f30001 (NS_ERROR_NOT_INITIALIZED) [nsIMessageSender.sendAsyncMessage]  ext-windows.js:19
Error: Could not establish connection. Receiving end does not exist.

[trev]

Please create a new issue on the Cancel button not working. It isn't reproducible for me, I suspect another extension interfering here.

[mapx]

it was reported here: https://issues.adblockplus.org/ticket/5979
by Ross

and the [Cancel] button does not do anything.

[mapx]

probably the same issue here:
https://issues.adblockplus.org/ticket/5988

buttons doing ..nothing

[mapx]

The issue still hitting Windows users for firefox 57 + ABP 3

[kzar]

Yes, I've just tested and while Wladimir's fix works for me on Linux it doesn't seem to on Windows 10.

[kzar]

I can also reproduce the problem with the buttons on Windows, I've opened #6053 for that. (No it's not a duplicate of #5988 unfortunately.)

[kzar]

I've been looking into why this problem is still happening on Windows 10. I notice that there's a Error: Could not establish connection. Receiving end does not exist. message showing up in the console when the "composer.dialog.init" message is sent, and the message is never received by the popup. I've tried adding a 100ms delay before sending the message, no dice. I then tried adding a 1 second delay and it worked.

Wladimir's fix seems correct to me, I guess we can't trust the onUpdated "complete" event :/.

[kzar]

I've opened a Firefox bug about that ​https://bugzilla.mozilla.org/show_bug.cgi?id=1418655

[kzar]

Annoyingly the error is not a real exception so we can't catch it, looking into what else we can do to workaround the problem on Windows 10.

[mapx]

The "1 second delay" does not work always ?

[kzar]

Annoyingly the error is not a real exception so we can't catch it...

My mistake, the API was promisified I just had to call .catch()!

The "1 second delay" does not work always ?

Well it seems to work reliably for me, but who knows that it would work reliably on a different computer. Hard coding pauses like this is a nasty hack :/

[abpbot]

A commit referencing this issue has landed:
​Issue 5817 - Retry sending suggested filters to block element dialog

[Ross]

In Firefox 57 / Windows 7 on Google: The highlight never appears.
In Firefox 57 / Windows 7 on ArsTechnica: The highlight works and the dialog appears but it sits disabled displaying "Loading..." for ages.

In Chrome 62 / Windows 7 on Google: The highlight never appears.
In Chrome 62 / Windows 7 on ArsTechnica: The highlight works, dialog appears and filter suggested as expected.

ABP 3.0.1.1939

[mapx]

chrome 63 / w 7 => on google selected element is highlighted on page(2 different languages)
firefox 58 / w 7 => on google selected element is highlighted on page

ABP 3.0.1.1939

[kzar]

Replying to Ross:

In Firefox 57 / Windows 7 on ArsTechnica: The highlight works and the dialog appears but it sits disabled displaying "Loading..." for ages.

In Chrome 62 / Windows 7 on ArsTechnica: The highlight works, dialog appears and filter suggested as expected.

This is the expected behaviour, we work around the Firefox bug on Windows by retrying once every second for three seconds. That's why I added the "Loading..." message to make it clear what was happening. Not ideal, but the best we can do until Mozilla fix the underlying problem.

In Firefox 57 / Windows 7 on Google: The highlight never appears.
In Chrome 62 / Windows 7 on Google: The highlight never appears.

Please could you file a separate issue for that?

[trev]

Replying to Ross:

In Chrome 62 / Windows 7 on Google: The highlight never appears.
In Chrome 62 / Windows 7 on ArsTechnica: The highlight works, dialog appears and filter suggested as expected.

As Sebastian explained on IRC, this is also expected behavior. With Acceptable Ads enabled, hiding anything on this page isn't possible. You can only block things, which makes the logo the only selectable element on this page.

[Ross]

Fixed. Block element works as expected. There is an issue still with block element in older Firefox versions (#6113).

(Thank you for explanations).

ABP 3.0.1.1939
Firefox 52 / 57 / Windows 10
Chrome 52 / 62 / Windows 7
Opera 39 / 49 / Windows 7