pictures uploaded from gallery are plain black on mako only

[Andreas Jung]

When I upload a picture to twitter via the webapp from my Ubuntu phone, the pictures appear as just plain black in the web. The preview in the webapp looks o.k.

The Bug is reproducable for me on this specific device. I have no other devices to test it further.
There are no errors and the connection type doesn't matter.

Device is mako | Version: RTM Ubuntu 14.10 (r11)

[Dario Cavedon (dcavedon)]

I confirm the problem, you can see a test at this link:

https://twitter.com/dcavedon/status/560516977161416704

You can reproduce this error every time:
- open Twitter web app
- write a new tweet
- insert a picture
- take the picture from the gallery or from file manager
- tweet it!

The result is a tweet with a completely black picture.

My device is mako, with Ubuntu 14.10 (r14).

[Andreas Jung (docjuhnk)]

Right now I'm having this bug when the phone is connected via w-lan.
-> https://twitter.com/docjuhnk/status/561100609592770560

When I use mobile web connection the upload works jus fine.
-> https://twitter.com/docjuhnk/status/561100895581376512

I could reproduce this with two tweets. One on r14, the other was sent from r15. (Device: mako)

[Alexandre Abreu (abreu-alexandre)]

To be noted: I am re-assigning to the proper ubuntu phone webapp project

[Alexandre Abreu (abreu-alexandre)]

I was able to repro it using #95 on mako, it works fine on RTM > #232

[Alexandre Abreu (abreu-alexandre)]

There seem to be a race somewhere, ... if one "Tweets" the picture as soon as it has been selected from the content picker it appears black, otherwise if one waits a bit (10 sec) *after* the picture has appeared in the tweet message box, then it shows up properly.

[Zachary Igielman (zacharyi123)]

Is this being fixed? It is still a problem.

[Alexandre Abreu (abreu-alexandre)]

Yes it is being worked on and planned for this work sprint

[Zachary Igielman (zacharyi123)]

Great, what do you mean by work sprint? When will this be fixed for me in the app? Great work, thanks man, you're awesome :D

[Alexandre Abreu (abreu-alexandre)]

The initial fix that tweaked the accept timer for the content picker dialog was a red herring. It seemed to work but it was most likely timing related.

As of now I cannot repro the scenario highlighted above: waiting a bit after the picture appeared in the composition dialog before posting it to make it work.

After inspecting the logs, I found this suspicious line

[0819/192717:ERROR:gles2_cmd_decoder.cc(8216)] [GroupMarkerNotSet(crbug.com/242999)!:8CA7A591]GL ERROR :GL_INVALID_ENUM : glReadPixels: format was GL_BGRA_EXT

right after posting the image, and that does not appear in other non mako contexts.

It *might* (still under investigation) be triggered when twitter reads back from the canvas that displays the image in the message composition dialog to get access to its content ... and seems be gpu related (GL_BGRA_EXT not being supported)

[David Barth (dbarth)]

The issue is most probably due to a GL operation that is not well supported on mako.

A complete fix may not be possible if this is a hardware limitation. And disabling the GL operation support might impact things like HTML games for example.

Since it's mako only, I would recommend to freeze that as a known-issue on this platform.