notifications: Try to guess app id if getting from hints fails

The notification spec states that the `desktop-entry` hint should be the prefix of the Desktop Application Info file. However, because of the push to have fully-qualified app ID's, some applications now have a mismatch between the ID and the desktop file, meaning the hint cannot be used for that application.

In cases where the hint fails, try to guess the ID using the application's name given to us from DBus.

It seems to fix #477.

Signed-off-by: Evan Maddock <maddock.evan@vivaldi.net>

src/lib/notification.vala

@@ -115,15 +115,27 @@
 				category = variant.get_string();
 			}
 
-			// Set the application ID and app info
+			// Try to set the application ID and app info
 			if ((variant = hints.lookup("desktop-entry")) != null && variant.is_of_type(VariantType.STRING)) {
 				app_id = variant.get_string();
 				app_id.replace(".desktop", "");
 				app_info = new DesktopAppInfo("%s.desktop".printf(app_id));
+			}
+
+			// Because following specs is a lost art, sometimes the desktop-entry
+			// value does not correspond to the desktop file. So, try to best-guess
+			// the desktop id instead.
+			if (app_info == null) {
+				app_id = app_name.replace(" ", "-").down();
+				app_info = new DesktopAppInfo("%s.desktop".printf(app_id));
+			}
 
-				if (app_info != null) app_name = app_info.get_string("Name") ?? app_name;
+			// Make sure we have the best app name
+			if (app_info != null) {
+				app_name = app_info.get_string("Name") ?? app_name;
 			}
 
+			// Try to get the application's image
 			app_image = get_appinfo_image(Gtk.IconSize.DND, app_id.down());
 
 			bool image_found = false;
@@ -272,4 +284,4 @@
 			return null;
 		}
 	}
- }
+}