[QA] Sharing dialog (often) shows no thumbnails

[jnweiger]

Seen with owncloud-client 2.9.0 beta3 on Linux connected to server 10.8.0

• also install owncloud-client-nemo
• wait until the sync is done.
• navigate to the sync folder with nemo, right click several files, open the owncloud -> sharing dialog

In the examples shown here, the portugal image does not show a thumbnail. Actually, when opening the dialog, system default thumbnail is shown briefly, then disappears.
The bicycle image has its thumbnail shown here. (server or client generated, not sure....)

[michaelstingl]

Log available?

[TheOneRing]

Core replies with an jpg instead of an png

[bishwasojha]

sharing in nemo , Image thumbnail is shown as follows

In Linux

In Windows

In Linux TESTED with ownCloud version

ownCloud 3.0.0.9005-beta1 [6b12ec](https://github.com/owncloud/client/commit/6b12ecdb4236d3d485ed57ec0bc2feac72b8f340)
Libraries Qt 5.15.2, OpenSSL 3.0.2 15 Mar 2022
Using virtual files plugin: suffix
ubuntu-5.15.0-52-generic

In Windows TESTED with ownCloud version

ownCloud 3.0.0.9005-beta1 [6b12ec](https://github.com/owncloud/client/commit/6b12ecdb4236d3d485ed57ec0bc2feac72b8f340)
Libraries Qt 5.15.5, OpenSSL 1.1.1q 5 Jul 2022
Using virtual files plugin: wincfapi
windows-10.0.19044

[individual-it]

@bishwasojha could you please retest again with beta2

[bishwasojha]

• with ocis , share button makes file open in web
• with oc10, previews are displayed correctly in Sharing dialog box

[michaelstingl]

• with ocis , share button makes file open in web

Different feature ➡️ #10206