Created attachment 351262 [details] [review]
Fix proposal

Review of attachment 351262 [details] [review]:

Can you please confirm why is this issue happening? GTK+ picks the application id as the icon, doesn't it?

I cannot explain why but in my case GTK+ does not seem to pick any icon.

I made some tests using the GTK inspector: the icon-name property of the GtdWindow object is not set. However, when I set it to "org.gnome.Todo" from the inspector, the icon appear.

Maybe the issue is caused by the fact that I am using gnome-flashback and metacity instead of gnome-shell and mutter.

Please find attached to this report a screenshot describing the issue.

Created attachment 351486 [details]
Issue screenshot

(In reply to larchunix from comment #3)

> Please find attached to this report a screenshot describing the issue.

I understand your problem. What I'm trying to figure out is whether this is an issue in GNOME To Do, or in GTK+ itself. Some questions:

 - Is there any other app that misbehaves like this?
 - On apps that work (e.g. Control Center?), is there a call to 'gtk_window_set_default_icon_name()'?
 - Which DE are you using? (Sorry, couldn't figure out from the screenshot)

(In reply to Georges Basile Stavracas Neto from comment #5)
> 
> I understand your problem. What I'm trying to figure out is whether this is
> an issue in GNOME To Do, or in GTK+ itself. Some questions:
> 
>  - Is there any other app that misbehaves like this?

I checked most of the GNOME applications installed on my computer; GNOME To Do appears to be the only one having this problem. 

>  - On apps that work (e.g. Control Center?), is there a call to
> 'gtk_window_set_default_icon_name()'?

It seems so (at least for the applications I tested):

● Cheese:
  └─ https://git.gnome.org/browse/cheese/tree/src/cheese-application.vala#n114
     └─ Window.set_default_icon_name ("org.gnome.Cheese");
● Evince
  └─ https://git.gnome.org/browse/evince/tree/shell/main.c#n299
    └─ gtk_window_set_default_icon_name ("evince");
● Gedit
  └─ https://git.gnome.org/browse/gedit/tree/gedit/gedit-app.c#n1444
     └─ gtk_window_set_default_icon_name ("gedit");
● GNOME 2048
  └─ https://git.gnome.org/browse/gnome-2048/tree/src/application.vala#n90
     └─ Window.set_default_icon_name ("gnome-2048");
● GNOME Boxes
  └─ https://git.gnome.org/browse/gnome-boxes/tree/src/app-window.vala#n138
     └─ Gtk.Window.set_default_icon_name ("gnome-boxes");
● GNOME Builder
  └─ https://git.gnome.org/browse/gnome-builder/tree/libide/application/ide-application.c#n550
     └─ gtk_window_set_default_icon_name ("org.gnome.Builder");
● GNOME Disks Utility
  └─ https://git.gnome.org/browse/gnome-disk-utility/tree/src/disks/gduwindow.c#n1021
     └─ gtk_window_set_icon_name (GTK_WINDOW (window), "gnome-disks"); 
● GNOME Power Statistics 
  └─ https://git.gnome.org/browse/gnome-power-manager/tree/src/gpm-statistics.c#n1731 
     └─ gtk_window_set_default_icon_name ("gnome-power-manager"); 
● GNOME Terminal
  └─ https://git.gnome.org/browse/gnome-terminal/tree/src/terminal-app.c#n423
     └─ gtk_window_set_default_icon_name (GNOME_TERMINAL_ICON_NAME);
● Nautilus
  └─ https://git.gnome.org/browse/nautilus/tree/src/nautilus-application.c#n1231
     └─ gtk_window_set_default_icon_name ("org.gnome.Nautilus");

>  - Which DE are you using? (Sorry, couldn't figure out from the screenshot)

Lately I have been using GNOME Flashback (formerly GNOME Fallback).

Perfect, thanks for the extensive research!

Attachment 351262 [details] pushed as b3d44e57 - application: set default icon name