Problem with change of toolbar's margin

[Sun Yijiang]

GNU Emacs CVS version under Linux.

The variable tool-bar-button-margin controls the toolbar's height. 
When I set this variable to a value other than it's default value, for
example, 2 or '(1 . 1), the toolbar's buttons "margin" changes, but
toolbar's "height" remains, which is still
icon_height+default_margin_value*2.  This makes a blank bar at the
bottom of the toolbar, looks ugly : (

Default value of tool-bar-button-margin is 4, defined in C Source,  so
I guess if there's some bug in toolbar display (I did not check the
source) that make toolbar's height a "constant", not a variable being
updated by value changing of tool-bar-button-margin.