gtk_widget_size_allocate(): attempt to allocate widget with width -19 and height 1

[Franco Broi <franco bordernet com au>]

Hi

I have an application built using Glade which has a grid inside an
expander, when I expand the expander I get a Gtk-WARNING even though
everything works as expected. Through trial and error I traced the
problem to the left margin set on the grid widget, if it's zero I don't
get a warning.

I tried putting the grid inside a box but setting a margin on the box
has the same problem.

Any ideas how to make the warning go away? It must be grid widget
related because I use expanders a lot but this is the only one with a
grid inside it.

I'm using Gtk 3.14 and here is a snippet of the Glade XML if it helps

   <object class="GtkExpander" id="expander10">
    <property name="visible">True</property>
    <property name="can_focus">True</property>
    <property name="resize_toplevel">True</property>
    <child>
     <object class="GtkGrid" id="grid2">
      <property name="visible">True</property>
      <property name="can_focus">False</property>
      <property name="halign">start</property>
      <property name="valign">start</property>
      <property name="margin_left">20</property>
      <property name="resize_mode">immediate</property>
      <property name="row_spacing">4</property>
      <property name="column_spacing">20</property>

Not a show stopper but annoying.

Cheers,