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

#479)"

This reverts commit bfee2a0.

src/lib/notification.vala

@@ -115,27 +115,15 @@
 				category = variant.get_string();
 			}
 
-			// Try to set the application ID and app info
+			// 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));
-			}
 
-			// Make sure we have the best app name
-			if (app_info != null) {
-				app_name = app_info.get_string("Name") ?? 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;
@@ -267,13 +255,9 @@
 
 		private Gtk.Image? get_appinfo_image(Gtk.IconSize size, string? fallback) {
 			if (app_info == null) {
-				var theme = Gtk.IconTheme.get_default();
-
-				if (!theme.has_icon(fallback)) {
-					return null;
-				}
-
-				return new Gtk.Image.from_icon_name(fallback, size);
+				var fallback_image = new Gtk.Image.from_icon_name(fallback, size);
+				var invalid_image = (fallback_image == null) || (fallback_image.icon_name == null) || (fallback_image.icon_name == "image-missing") || (fallback_image.icon_name == "");
+				return invalid_image ? null : fallback_image;
 			}
 
 			var app_icon_name = app_info.get_string("Icon"); // Use the Icon from the respective DesktopAppInfo or fallback to generic applications-internet
@@ -288,4 +272,4 @@
 			return null;
 		}
 	}
-}
+ }