1527235 - Images copied to clipboard no longer contain transparency/alpha channel.

Status: VERIFIED FIXED

(Core :: Widget: Win32, defect, P3)

Description

[MarkRH]

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:65.0) Gecko/20100101 Firefox/65.0

Steps to reproduce:

From this Reddit thread: https://www.reddit.com/r/firefox/comments/apl1he/firefox_v65_images_copied_to_clipboard_no_longer/ when viewing the image https://www.mariowiki.com/images/9/9c/Goomba_-_MarioPartyStarRush.png and then right-clicking on image and Copy Image and then pasting into Gimp for example, the alpha/transparency channel is lost.

I ran a moz-regression with the following results:

Using url: https://hg.mozilla.org/integration/mozilla-inbound/json-pushes?changeset=6c28ad7f98a7629f5a1b2f123aaad66f1f6233f0&full=1
2019-02-12T00:41:06: DEBUG : Found commit message:
Bug 1501482. r=tnikkel

Differential Revision: https://phabricator.services.mozilla.com/D11897
pushlog_url: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=a424be1d8a667c799cbe4f337626591b1087f14d&tochange=6c28ad7f98a7629f5a1b2f123aaad66f1f6233f0
repo_name: mozilla-inbound

I do not have access to bug 1501482 to see what it is.

Actual results:

Alpha/Transparency channel is lost during copy operation.

Expected results:

It should have retained the alpha channel information.

Comment 1

[Gingerbread Man]

Attachment: testcase.png

Comment 2

[Gingerbread Man]

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:67.0) Gecko/20100101 Firefox/67.0
20190211215545

Thank you for the report. I'm surprised to see this has ever worked in GIMP when it doesn't work in other applications and bug 460969 has been open since 2008.

Narrow push log:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=ae143b5f65fb4a80538e765541de7f999c909233&tochange=6c28ad7f98a7629f5a1b2f123aaad66f1f6233f0

Comment 3

[MarkRH]

Yeah, I couldn't get Irfanview to see the Alpha no matter what I used (even copying from GIMP). Apparently GIMP can see something in the clipboard that Irfanview doesn't.

Comment 4

[Liz Henry (:lizzard) (relman/hg->git project)]

Andrew, can you take a look here since you worked on bug 1501482?

Comment 5

[Andrew Osmond [:aosmond] (he/him)]

Reviewing the code, I suspect we need to add the bpp option for the BMP encoder to ensure the alpha channel gets added.

Comment 6

[Andrew Osmond [:aosmond] (he/him)]

I tried without the fix, missing the alpha channel, with the fix, has the alpha channel:

try: https://treeherder.mozilla.org/#/jobs?repo=try&revision=7feffb54ee92e477b6d18dbe7ef245c00eed3895&selectedJob=228452811

Comment 7

[Andrew Osmond [:aosmond] (he/him)]

Attachment: Bug 1527235 - Fix how the alpha channel was missing from pasted clipboard images.

In order to get the alpha channel when encoding BMP images from a
surface, we need to supply bmp=32 in the encoder options.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/80e1aa2d7459
Fix how the alpha channel was missing from pasted clipboard images. r=tnikkel

Comment 9

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/80e1aa2d7459

Comment 10

[MarkRH]

Has this been pushed to the latest Nightly yet? Still not working there.

Name Firefox
Version 67.0a1
Build ID 20190215162352

Comment 11

[MarkRH]

Ok, Nightly just updated again and now it works, at least as far as Gimp seeing the Alpha channel.

Name Firefox
Version 67.0a1
Build ID 20190215184035

Comment 12

[Andrew Osmond [:aosmond] (he/him)]

(In reply to MarkRH from comment #11)

Ok, Nightly just updated again and now it works, at least as far as Gimp seeing the Alpha channel.

Name Firefox
Version 67.0a1
Build ID 20190215184035

Thanks for confirming. I'll request uplift.

Comment 13

[Andrew Osmond [:aosmond] (he/him)]

Comment on attachment 9043984 [details]
Bug 1527235 - Fix how the alpha channel was missing from pasted clipboard images.

Beta/Release Uplift Approval Request

Feature/Bug causing the regression

Bug 1501482

User impact if declined

Images with transparency that are pasted from the clipboard on Windows will lose it.

Is this code covered by automated tests?

Yes

Has the fix been verified in Nightly?

Yes

Needs manual test from QE?

No

If yes, steps to reproduce

List of other uplifts needed

None

Risk to taking this patch

Low

Why is the change risky/not risky? (and alternatives if risky)

I only changed the configuration of the BMP encoder to output BMPs in a form that supports alpha instead of the default which is without. The encoder itself has long supported encoding with/without alpha.

String changes made/needed

None

Comment 14

[Liz Henry (:lizzard) (relman/hg->git project)]

Comment on attachment 9043984 [details]
Bug 1527235 - Fix how the alpha channel was missing from pasted clipboard images.

Fix for recent regression (from 65), verified in Nightly.
OK to uplift for beta 8.

Comment 15

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/releases/mozilla-beta/rev/c341768d99a4

Comment 16

[MarkRH]

Just wanted to confirm that it now works for me in 66 beta 9 (did not in beta 8).

Comment 17

[Job Bautista]

Seems to be back again: https://www.reddit.com/r/firefox/comments/mwmhu7/copied_pngs_have_a_black_background_instead_of/

Comment 18

[Timothy Nikkel (:tnikkel)]

Please file a new bug, and if you can get a regression range using https://mozilla.github.io/mozregression/ that would be great thanks. Please cc me.

Comment 19

[Job Bautista]

Hello Timothy, sorry for the late response. I'm not sure if this is even worth creating a new bug for, since it seems that this is not a browser problem, but the image editor's. The reporter on Reddit says that this also occurs on Google Chrome.