[gtk/matthiasc/for-master: 2/2] page setup dialog: Prevent cascading paper dialogs

[Matthias Clasen <matthiasc src gnome org>]

commit 8e74687ab30a9579234da3e0d8d92ae22aaee19a
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Aug 29 16:29:28 2020 -0400

    page setup dialog: Prevent cascading paper dialogs
    
    We trigger the paper dialog when the "manage" item
    in the dropdown is selected. But the selection also
    changes due to internal changes, such as reloading
    the custom paper list when the paper dialog is
    closed. We need to be extra careful to avoid triggering
    another paper dialog when that happens.
    
    Fixes: #3098

 gtk/gtkpagesetupunixdialog.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkpagesetupunixdialog.c b/gtk/gtkpagesetupunixdialog.c
index 190a9f7e9a..ed8135eb34 100644
--- a/gtk/gtkpagesetupunixdialog.c
+++ b/gtk/gtkpagesetupunixdialog.c
@@ -81,6 +81,8 @@ struct _GtkPageSetupUnixDialog
 
   GtkPrintSettings *print_settings;
 
+  gboolean internal_change;
+
   /* Save last setup so we can re-set it after selecting manage custom sizes */
   GtkPageSetup *last_setup;
 };
@@ -273,6 +275,7 @@ gtk_page_setup_unix_dialog_init (GtkPageSetupUnixDialog *dialog)
   GtkFilter *filter;
   GtkPageSetup *page_setup;
 
+  dialog->internal_change = TRUE;
   dialog->print_backends = NULL;
 
   gtk_widget_init_template (GTK_WIDGET (dialog));
@@ -337,6 +340,7 @@ gtk_page_setup_unix_dialog_init (GtkPageSetupUnixDialog *dialog)
   /* Load data */
   gtk_print_load_custom_papers (dialog->custom_paper_list);
   load_print_backends (dialog);
+  dialog->internal_change = FALSE;
 }
 
 static void
@@ -638,11 +642,19 @@ custom_paper_dialog_response_cb (GtkDialog *custom_paper_dialog,
                                  gpointer   user_data)
 {
   GtkPageSetupUnixDialog *dialog = GTK_PAGE_SETUP_UNIX_DIALOG (user_data);
+  GtkPageSetup *last_page_setup;
 
+  dialog->internal_change = TRUE;
   gtk_print_load_custom_papers (dialog->custom_paper_list);
-
-  /* Update printer page list */
   printer_changed_callback (GTK_DROP_DOWN (dialog->printer_combo), NULL, dialog);
+  dialog->internal_change = FALSE;
+
+  if (dialog->last_setup)
+    last_page_setup = g_object_ref (dialog->last_setup);
+  else
+    last_page_setup = gtk_page_setup_new (); /* "good" default */
+  set_paper_size (dialog, last_page_setup, FALSE, TRUE);
+  g_object_unref (last_page_setup);
 
   gtk_window_destroy (GTK_WINDOW (custom_paper_dialog));
 }
@@ -660,6 +672,9 @@ paper_size_changed (GtkDropDown            *combo_box,
   GtkLabel *label;
   const char *unit_str;
 
+  if (dialog->internal_change)
+    return;
+
   label = GTK_LABEL (dialog->paper_size_label);
 
   selected = gtk_drop_down_get_selected (GTK_DROP_DOWN (combo_box));