Pasting another test case from previous bug report - element's sizes & paddings & margins are rendered differently (correctly) what causes some weird positioning errors to happen.

Here: width on first element and border-left on second are both 51px but because of this strange border-connected behaviour border is shown as 50.40px (b_boxModel.png) and part of the black element (which should be overlapped by yellow one) can be seen (result.png).

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I can't reproduce using your test.html and the steps in the report. 

I assume you used zoom somewhere, but it's not part of the repro steps in the report. Please specify the exact steps you followed. 

Also, please consider that if Firefox's behaviour is identical to Chrome's, it is quite likely that the behaviour is correct.

Right.
First of all, if you have looked into the link to "previous issue" then you should see the comment made by "pfeldman@chromium.org":

"The issue here is that the page is zoomed it to 125%.

window.getComputedStyle($0).borderWidth gives me 4.8.

Looks like we are trying to render border with the counting number of pixels and work it back to show as computed. For 125% zoom, we have:

Math.floor(5 * 1.25) / 1.25 == 4.8"


I don't know if there is any other way to reproduce it (maybe it's possible to ask somebody from the linked issue?) - on my machine I have setup as follows:

I'm on Win 10 and in Display settings (Settings->System->Display) I have chosen "125%: option under "Scale and layout" -> "Change the size of text, apps, and other items" (see attachment).

Well, what will be the way to check if "that behaviour is correct"? By literally reading w3 standard or is there a more sophisticated approach?
Hard to believe it's working as it should - as you can see on result.png this behaviour is causing layout errors (it's not possible to implement a layout without "holes" or overlapping elements which is a huge discomfort for users with scaled views).

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Thank you for providing more feedback. Adding requester "gracec@chromium.org" to the cc list and removing "Needs-Feedback" label.

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Tested the issue on Win-10 using chrome reported version #61.0.3163.100, latest stable #62.0.3202.75 and latest canary #64.0.3253.0.

Attached a screen cast and screenshot for reference.

Following are the steps followed to reproduce the issue.
------------
1. Opened the attached file "test2.html" and zoomed the display to 125%.
2. Observed that rendered border width was 951.2 x 50 px as per the attached screenshot.

jakub.freisler@ - Could you please check the attached screen cast or screenshot and please let us know if anything missed from our side to reproduce the issue.

Thanks...!!

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Thanks krajshree@ you helped me realise one thing - machine on which I was testing both files (test.html & test2.html) wasn't connected to the internet for some time now and chrome's version there was still 56.0.2924.87.

Now, I confirm that in newest stable release (61) everything works as expected, so somewhere between releases 56-61 it has had been fixed - and firefox still fails.

Sorry for confusion and thank you guys for your work!

Thank you for providing more feedback. Adding requester "krajshree@chromium.org" to the cc list and removing "Needs-Feedback" label.

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jakub.freisler@ Thanks for the feedback.

As per comment 7, as everything is working as expected, can you please confirm if we can close this issue?

Thanks..

susanjuniab@ Sure - I'm confirming that everything works as expected and this issue can be closed.

Thank you for providing more feedback. Adding requester "susanjuniab@chromium.org" to the cc list and removing "Needs-Feedback" label.

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Closing the issue as per #10.