[gtk/focus-workaround] gridview: Work around unexpected focus changes

[Matthias Clasen <matthiasc src gnome org>]

commit c13d70479bfa223d44c21c16cf8a071e85d8e726
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Aug 6 14:35:19 2020 -0400

    gridview: Work around unexpected focus changes
    
    As things currently stand, we get events for focus changes
    before the widget is allocated, and try to scroll in response.
    Therefore, leaving n_columns at 0 until size-allocate leads
    to plenty of division-by-zero. Just set it to 1 initially
    to avoid that. This is a workaround for #3025.

 gtk/gtkgridview.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/gtk/gtkgridview.c b/gtk/gtkgridview.c
index ecbb741f8f..a945683b03 100644
--- a/gtk/gtkgridview.c
+++ b/gtk/gtkgridview.c
@@ -1167,6 +1167,7 @@ gtk_grid_view_init (GtkGridView *self)
 
   self->min_columns = 1;
   self->max_columns = DEFAULT_MAX_COLUMNS;
+  self->n_columns = 1;
 
   gtk_list_base_set_anchor_max_widgets (GTK_LIST_BASE (self),
                                         self->max_columns * GTK_GRID_VIEW_MAX_VISIBLE_ROWS,