1785194 - Links in pre tag not rendering consistently

Status: RESOLVED WORKSFORME

(Core :: Graphics: WebRender, defect)

Description

[joebobson87]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:103.0) Gecko/20100101 Firefox/103.0

Steps to reproduce:

I tried to render the following HTML, eg in the HTML demo box on https://developer.mozilla.org/en-US/docs/Web/HTML/Element/pre, or on a site like https://html.onlineviewer.net/

<pre>
<a target="_blank" href="https://ad.doubleclick.net/">foo</a>
<a target="_blank" href="https://ad.doubleclick.net">bar</a>
<a target="_blank" href="https://ad.doublclick.net/">baz</a>
<a target="_blank" href="https://pubads.g.doubleclick.net/">bat</a>
</pre>

Actual results:

The middle two links render, while the first and last are invisible.

Expected results:

All four links should have been displayed

Comment 1

[joebobson87]

The issue is actually visible in this ticket: when viewed in Firefox, two lines are missing, which are visible when viewed in eg Safari or Chrome.

Comment 2

[Hani Yacoub, Desktop QA]

Attachment: Screenshot 2022-08-25 at 16.30.50.png

Here are the results comparing Firefox and Chrome and I can't see any differences.
On both browsers only two links are displayed.
Could you please help me with a screenshot to see how things look on your end?
Thanks.

Comment 3

[joebobson87]

Sure, here is a screenshot of Chrome, Safari and FF on macOS: https://ibb.co/6RVBVRH

I think maybe the issue is that you copied the rendered code from here? I will try to paste the HTML snippet again in a code block so that it isn't rendered.

<pre>
str: <a target="_blank" href="https://ad.doubleclick.net/">https://ad.doubleclick.net/</a>

str: <a target="_blank" href="https://ad.doubleclick.net">https://ad.doubleclick.net</a>

str: <a target="_blank" href="https://ad.doublclick.net/">https://ad.doublclick.net/</a>

str: <a target="_blank" href="https://pubads.g.doubleclick.net/gampad/ads?caps">https://pubads.g.doubleclick.net/gampad/ads?caps</a>
</pre>

Comment 4

[Hani Yacoub, Desktop QA]

Attachment: Screenshot 2022-08-26 at 14.26.29.png

Comparing Firefox with Chrome and Safari, on my end Firefox and Chrome are behaving the same.
I'll set this as new so the engineering team could decide if they take in consideration changing this.

Comment 5

[Hani Yacoub, Desktop QA]

After during further investigation I observed that the issue is only reproducible on Firefox 104.0 and I can't reproduce it on Firefox 105.0b3 or on Firefox Nightly 106.0a1, I expect that the fix will be also on Firefox 105.0 once it will be landed.
I'll keep the issue as unconfirmed and will check it later if it's got fixed.

Comment 6

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

The Bugbug bot thinks this bug should belong to the 'Core::Graphics: WebRender' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 7

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

The severity field is not set for this bug.
:gw, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 8

[Hani Yacoub, Desktop QA]

Could you please check if the issue is fixed on you end on the latest Firefox?
Thanks.

Comment 9

[joebobson87]

Hi Hani, thanks for looking into this.

On FF 107.0 (latest available for my system, MacBook Air M1 2020, Ventura 13.0.1), one of the examples is fixed but not the other (the top one).

Specifically, here is a minimal reproduction of the bug

<a href="https://ad.doubleclick.net/">foo</a>

Nothing is rendered, whereas it should render foo

Removing the trailing slash in the URL fixes the issue, as does removing almost any of the characters.

Comment 10

[joebobson87]

(In reply to joebobson87 from comment #9)

Hi Hani, thanks for looking into this.

On FF 107.0 (latest available for my system, MacBook Air M1 2020, Ventura 13.0.1), one of the examples is fixed but not the other (the top one).

Specifically, here is a minimal reproduction of the bug

<a href="https://ad.doubleclick.net/">foo</a>

Nothing is rendered, whereas it should render foo

Removing the trailing slash in the URL fixes the issue, as does removing almost any of the characters.

in order to display it more clearly:
<pre><a href="https://ad.doubleclick.net/">foo</a></pre>

Comment 11

[Darkspirit]

(In reply to joebobson87 from comment #3)

Sure, here is a screenshot of Chrome, Safari and FF on macOS: https://ibb.co/6RVBVRH

uBlock Origin blocks 1 item.
Do you see the same problem with uBlock Origin disabled?

Comment 12

[joebobson87]

(In reply to Darkspirit from comment #11)

(In reply to joebobson87 from comment #3)

Sure, here is a screenshot of Chrome, Safari and FF on macOS: https://ibb.co/6RVBVRH

uBlock Origin blocks 1 item.
Do you see the same problem with uBlock Origin disabled?

Ah, that's it! 🤦‍♂️
Of course it makes sense, since doubleclick.net is an ad-serving domain.

Disabling uBlock Origin fixes it. So I guess this is fixed.