QL Codes: Wifi URI is not opened with "Open URL" and copy to clipboard does not seem to work with "Copy".

[AndyM48]

(copied from https://gitlab.com/postmarketOS/megapixels/-/issues/72 running version megapixels-1.7.0-r0 on Linux 6.6.3 with pmos)

So I am trying to work out what megapixels is doing with the QR code; My knowledge is extremely limited so please bear with me:

1. I cannot see how to debug the code. There are very few messages logged in normal use.
2. I have found the following code which seems to be relevant:

main.c #612

on_zbar_code_tapped(GtkWidget *widget, const MPZBarCode *code)
{
        GtkWidget *dialog;
        GtkDialogFlags flags = GTK_DIALOG_MODAL | GTK_DIALOG_DESTROY_WITH_PARENT;
        bool data_is_url =
                g_uri_is_valid(code->data, G_URI_FLAGS_PARSE_RELAXED, NULL);

        char *data = strdup(code->data);

        if (data_is_url) {
                dialog = gtk_message_dialog_new(
                        GTK_WINDOW(gtk_widget_get_root(widget)),
                        flags,
                        GTK_MESSAGE_QUESTION,
                        GTK_BUTTONS_NONE,
                        "Found a URL '%s' encoded in a %s.",
                        code->data,
                        code->type);
                gtk_dialog_add_buttons(
                        GTK_DIALOG(dialog), "_Open URL", GTK_RESPONSE_YES, NULL);
        } else {
                dialog = gtk_message_dialog_new(
                        GTK_WINDOW(gtk_widget_get_root(widget)),
                        flags,
                        GTK_MESSAGE_QUESTION,
                        GTK_BUTTONS_NONE,
                        "Found data encoded in a %s.",
                        code->type);
                gtk_message_dialog_format_secondary_markup(
                        GTK_MESSAGE_DIALOG(dialog), "<small>%s</small>", code->data);
        }
        gtk_dialog_add_buttons(GTK_DIALOG(dialog),
                               "_Copy",
                               GTK_RESPONSE_ACCEPT,
                               "_Cancel",
                               GTK_RESPONSE_CANCEL,
                               NULL);

        g_signal_connect(
                dialog, "response", G_CALLBACK(on_zbar_dialog_response), data);

        gtk_widget_show(GTK_WIDGET(dialog));
}

main.c #588

on_zbar_dialog_response(GtkDialog *dialog, int response, char *data)
{
        g_autoptr(GError) error = NULL;
        switch (response) {
        case GTK_RESPONSE_YES:
                if (!g_app_info_launch_default_for_uri(data, NULL, &error)) {
                        g_printerr("Could not launch application: %s\n",
                                   error->message);
                }
        case GTK_RESPONSE_ACCEPT: {
                GdkDisplay *display = gtk_widget_get_display(GTK_WIDGET(dialog));
                gdk_clipboard_set_text(gdk_display_get_clipboard(display), data);
        }
        case GTK_RESPONSE_CANCEL:
                break;
        default:
                g_printerr("Wrong dialog response: %d\n", response);
        }

        g_free(data);
        gtk_window_destroy(GTK_WINDOW(dialog));
}

The first appears to check whether the entry is a valid URL, and, if true; adds the line "Found a URL '%s' encoded in a %s." and adds a button "_Open URL". If false; adds the line "Found data encoded in a %s." It then adds two buttons "_Copy" and "_Cancel".

The second appears to handle the response to the dialog. On "YES" attempts to launch the URL and if that fails then prints an error "Could not launch application: %s\n". ON "ACCEPT" copies the data to the clipboard. On "CANCEL" breaks.

I have tried three different QR codes with the following results:

1. Code for a simple address: Correctly shows the address and only shows buttons for Copy and Cancel. Select Copy, leave megapixels open, enter wl-paste in a terminal, address is not found in the clipboard.
2. Code for a wifi uri: First set an xdg-mime type for a wifi uri. Test it with xdg-open 'wifi code' (note the single inverted commas). Enter wl-paste in a terminal, wifi code has been copied and is correctly retrieved from the clipboard. Now try by scanning the QR code with megapixels; correctly shows the wifi code and shows the three buttons Open URL, Copy and Cancel. Select Open URL, prints "Could not launch application: The specified location is not supported"
3. Code for a URL: TL;DR opens the URL in the browser.

Speculation:

The URL/URI is accepted because G_URI_FLAGS_PARSE_RELAXED allows the semi-colons to pass. Normally a URL should/would not include semi-colons whereas a wifi URI will have them. Possibly the wifi URI is passed without escaping the semi-colons, or quoting the wifi-code?

Could the failure to copy be to do with wayland? Above I used wayland copy/paste to access the clipbooard. I have tried some other clipboard utilities, but without any more success.