filechooser: set default widget early for 'Rename' popover

because otherwise this second[1] popover will not be
able to save the filechooser default widget (the 'save'
button) because the first popover has not yet restablish
it (as will be done on popover's unmap handler).

[1] second because 'Rename' popover is launched from inside
    the 'file properties' popover.

Fixes #2555

gtk/gtkfilechooserwidget.c

@@ -73,6 +73,7 @@
 #include "gtkmain.h"
 #include "gtkscrollable.h"
 #include "gtkpopover.h"
+#include "gtkpopoverprivate.h"
 #include "gtkrevealer.h"
 #include "gtkspinner.h"
 #include "gtkseparator.h"
@@ -1680,7 +1681,16 @@ rename_file_cb (GSimpleAction *action,
   GtkFileChooserWidget *impl = data;
   GtkFileChooserWidgetPrivate *priv = impl->priv;
   GtkTreeSelection *selection;
+  GtkWidget *prev_default;
+  GtkWindow *window;
 
+  prev_default = gtk_popover_get_prev_default (GTK_POPOVER (priv->browse_files_popover));
+  if (prev_default) {
+    /* set 'default' early so rename popover can get it */
+    window = GTK_WINDOW (gtk_widget_get_ancestor (priv->browse_files_popover, GTK_TYPE_WINDOW));
+    if (window)
+      gtk_window_set_default (window, prev_default);
+  }
   /* insensitive until we change the name */
   gtk_widget_set_sensitive (priv->rename_file_rename_button, FALSE);
 

gtk/gtkpopover.c

@@ -674,6 +674,15 @@ gtk_popover_set_state (GtkPopover *popover,
     }
 }
 
+GtkWidget *
+gtk_popover_get_prev_default (GtkPopover *popover)
+{
+  g_return_val_if_fail (GTK_IS_POPOVER (popover), NULL);
+
+  return popover->priv->prev_default;
+}
+
+
 static void
 gtk_popover_map (GtkWidget *widget)
 {

gtk/gtkpopoverprivate.h

@@ -23,6 +23,7 @@
 G_BEGIN_DECLS
 
 void gtk_popover_update_position (GtkPopover *popover);
+GtkWidget *gtk_popover_get_prev_default (GtkPopover *popover);
 
 G_END_DECLS