Should cell renderer properties be cleared

[Federico Mena Quintero <federico ximian com>]

I have a text cell renderer and its data func looks like this:

static void
data_func (GtkTreeViewColumn *column, GtkCellRenderer *cell,
GtkTreeModel *model, GtkTreeIter *iter, gpointer data)
{
	if (some_condition ())
		g_object_set (cell, "markup", 
			      "<span weight=\"bold\">I'M BOLD</span>",
			      NULL);
	else
		g_object_set (cell, "text", "I'm not bold", NULL);
}

However, this makes the tree display mess up badly.  Say the data_func
gets called for a bold item, so it sets the "markup" property.  However,
if the next invocation of data_func is for a non-bold item, the cell
renderer will keep its extra_attrs set and the "I'm not bold" text will
have a chunk of bold text and a non-bold section as well --- this
changes in random ways when you scroll the tree.

To fix this, in my "else" clause I have to do

	g_object_set (cell, 
		      "text", "I'm not bold", 
		      "attributes", NULL,
		      NULL);

Or escape the text into markup without tags and set the "markup"
property, but this is ugly.

This is cumbersome.  Should the treeview reset a cell renderer's
parameters to the defaults between invocations of the data_funcs?

  Federico