Work around errors saving JPEG files with the glycin pixbuf loader

[cameronwhite]

This requires explicitly converting to a Gdk.Pixbuf which doesn't contain alpha.

Bug: #1774

[Piscium]

I built from your branch but sadly it did not fix the issue for me.
I am on Arch with the the most recent version of gdk-pixbuf2 installed (2.44.3).
What I used in the build:

source=("https://github.com/PintaProject/Pinta/archive/refs/heads/fix/glycin-jpeg.zip")

GLib.GException: Remote error: org.gnome.glycin.Error.InternalEditorError: glycin-loaders/glycin-image-rs/src/editor.rs:129:22: Internal error: The encoder or decoder for Jpeg does not support the color type `Rgba8`

stderr:
Setting process memory limit

   at GdkPixbuf.Pixbuf.SaveToStreamv(OutputStream stream, String type, String[] optionKeys, String[] optionValues, Cancellable cancellable)
   at Pinta.Core.JpegFormat.DoSave(Pixbuf pb, File file, String fileType, Window parent)
   at Pinta.Core.GdkPixbufFormat.Export(Document document, File file, Window parent)
   at Pinta.Actions.SaveDocumentImplmentationAction.SaveFile(Document document, File file, FormatDescriptor format, Window parent)
   at Pinta.Actions.SaveDocumentImplmentationAction.SaveFileAs(Document document)
   at Pinta.Actions.SaveDocumentImplmentationAction.Activated(Object sender, DocumentCancelEventArgs e)
   at Pinta.Core.FileActions.RaiseSaveDocument(Document document, Boolean saveAs)
   at Pinta.Core.Document.Save(Boolean saveAs)
   at Pinta.Actions.SaveDocumentAsAction.Activated(Object sender, EventArgs e)
   at Pinta.Core.Command.<.ctor>b__29_0(SimpleAction o, ActivateSignalArgs args)
   at GObject.Closure.InternalCallback(IntPtr closure, IntPtr returnValuePtr, UInt32 nParamValues, IntPtr paramValuesData, IntPtr invocationHint, IntPtr userData)

[cameronwhite]

I built from your branch but sadly it did not fix the issue for me. I am on Arch with the the most recent version of gdk-pixbuf2 installed (2.44.3). What I used in the build:

Hmm, that's interesting. I was testing on a VM with CachyOS (Arch-based) which is on gdk-pixbuf2 2.44.3-1.1, and this did work for me

It sounds like you downloaded the zip - were you running the Makefiles to build and install It on your system, or just running dotnet run --project Pinta?
If it's the former, maybe double check that you actually replaced whatever old version was installed?

[Piscium]

There was an error in my PKGBUILD. I will rebuild and retest later. Sorry for the noise.

[Piscium]

PKGBUILD fixed. I have done only a 30 seconds test of the issue at hand, namely, the saving of a file in jpeg, and it works.
Thanks for finding a fix!

[cameronwhite]

Great, thanks for confirming!