There is a bug where left-clicking a hidden layer in the toolbar successfully makes the layer visible in the layout but fails to update the toolbar icon to the "active" state.
The root cause is a positional argument mismatch in magic::toolupdate. When the Magic C-core issues a callback for a "see" command with two arguments, the third argument (layerlist) is passed as an empty string ("") rather than being omitted. This prevents the Tcl procedure from falling back to its hardcoded default of "none", causing the script to skip the logic that reassigns $yesno to "yes".
This patch changes the default value of $layerlist to "" and updates the conditional check to ensure the state and layer name are correctly reassigned regardless of how the C-core signals the update.
c3ee33e9a1