"Whoa! Firefox Screenshots went haywire..." error is displayed if the "Copy", "Download" or "Save" button is clicked for a screenshot selection that exceeds 32800 pixels

[Softvision-CristinaBadescu]

[Affected versions]:

• Nightly 59.0a1
• Screenshots 25.0.0

[Affected Platforms]:

• All Windows
• All Mac
• All Linux

[Steps to reproduce]:

1. Open the browser with the profile from prerequisites and navigate to a very long page (eg. https://imgur.com)
2. Perform a very long shot, that exceeds 32.800 pixels.
3. Click on the "Copy", "Download" or "Save" button.

[Expected result]:

• A friendly-user message is displayed to inform the user that the selection has a pixels limit. or
• The selection is successfully copied, downloaded or saved.

[Actual result]:

• "Whoa! Firefox Screenshots went haywire...?" system error notification is displayed.

[Notes]:

• Here is a screenshot with the browser console error:

• Here is a screen recording of the issue:

[jaredhirsch]

The max size of a canvas is 32767 pixels on a side, so we could either show a warning (easy) or stitch multiple canvases together (hard, but could fix other bugs, like parallax background issues).

[chenba]

Did we ever reach a decision on what to do here? We could, in addition to a warning, prevent a selection with a side greater than 32767 pixels. @johngruen ?

[jaredhirsch]

Throwing this back into triage to discuss

[ghost]

Let's prevent the selection box from being dragged past the limit

[chenba]

There is an area limit of 472,907,776 pixels. That should be taken into account as well. And devicePixelRatio need to be factored into the calculations for HiDPI.

[djh42]

This problem [also] occurs when selecting the entire page - so there's no dragging involved!

Also why is there a haywire error when I cancel a download?

[chenba]

@djh42 The issue with download cancellations will be fixed in the next Firefox release.

[crash5]

Hi!

Any new about this bugfix or some solution in client side? (like set some value in about:config)

I try to take a full page screenshot on this page and get the same error: https://www.codemag.com/Article/1001061/S.O.L.I.D.-Software-Development-One-Step-at-a-Time

[xmstspider]

DISCLAIMER: Workaround only - not sure if this is without potential side effects, it works for me, I am not taking responsibility if it blows your microwave oven or kills your cat...

1. Unzip firefox/browser/features/[email protected]
2. Edit webextension/build/buildSettings.js:

You see:

pngToJpegCutoff: parseInt("" || 2500000, 10),
maxImageHeight: parseInt("" || 10000, 10),
maxImageWidth: parseInt("" || 10000, 10)

I changed to

pngToJpegCutoff: parseInt("" || 2500000, 10),
maxImageHeight: parseInt("" || 10000, 10),
maxImageWidth: parseInt("" || 10000, 10)

3. If needed, alter the filename format under webextension/build/shot.js:get filename(), because the current settings sucks (especially because of getMonth)
4. zip again (in the same directory as install.rdf, type:

zip -r ../[email protected] .

or an equivalent in your favorite OS.

replace the extension under firefox/browser/features/[email protected]

@mozilla-services: Please fix this properly by creating an UI. This is a great function, but the defaults are not optimal.