Bug 494414

Summary:	Dolphin, Krusader, open/save dialogs: preview of PNG and HEIF files not shown anymore (others are fine)
Product:	[Frameworks and Libraries] frameworks-kio	Reporter:	slartibart70
Component:	Open/save dialogs	Assignee:	KIO Bugs <kio-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	alex.bikadorov, kdelibs-bugs-null, kfm-devel, med.medin.2014, public.paul.meier+kde
Priority:	NOR
Version First Reported In:	6.7.0
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	file-open preview

Description slartibart70 2024-10-10 12:15:58 UTC

open a browser, for example, press Ctrl-O to display the file-open dialog.
Press F11 to show the preview panel

Notice, that clicking on PNG files do only display a placeholder icon in the preview, other file-types (that i have tested) do work normally and do display a preview image.

Normal operation of dolphin is surprisingly ok (e.g. start dolphin at the commandline)
The same error is with directories - 'normal' dolphin displays a folder icon with up to 4 preview thumbnails, 'open file' does not.

Comment 1 slartibart70 2024-10-10 12:17:32 UTC

Created attachment 174617 [details]
file-open preview

Comment 2 slartibart70 2024-10-10 12:18:15 UTC

Operating System: Fedora Linux 40
KDE Plasma Version: 6.2.0
KDE Frameworks Version: 6.7.0
Qt Version: 6.7.2
Kernel Version: 6.10.13-200.fc40.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 PRO 7840U w/ Radeon 780M Graphics
Memory: 58,5 GiB of RAM
Graphics Processor: AMD Radeon 780M
Manufacturer: LENOVO
Product Name: 21K5000JGE
System Version: ThinkPad P14s Gen 4

Comment 3 Alex Bikadorov 2024-10-21 15:38:31 UTC

After the last system update I have the same problem - in the preview side view in file open/save dialogs and in Krusader. 

Krusader is using KIO::KImageFilePreview to show file previews and when selecting a PNG file this is written as debug message:

> kf.coreaddons: "Could not find plugin gdk-pixbuf-thumbnailer"

I have gdk-pixbuf2 (2.42.12) installed.

My environment:
Operating System: Arch Linux 
KDE Plasma Version: 6.2.1
KDE Frameworks Version: 6.7.0
Qt Version: 6.8.0
Kernel Version: 6.11.4-arch1-1 (64-bit)
Graphics Platform: Wayland

Comment 4 medin 2024-10-26 22:52:49 UTC

In plasma 6.2.2, the problem is at two places: information panel in Dolphin and also the preview panel in open/save dialogs, they fail to show preview of some formats like heif, png

While previews of png, heif… are correctly generated in the regular view inside Dolphin.

Running Dolphin from terminal shows the following error:
kf.coreaddons: "Could not find plugin gdk-pixbuf-thumbnailer"