|This function is PROTECTED, and can only be called from Blizzard code.|
Cancels the spell awaiting target selection.
Also cancels some types of weapon buffs when they ask for confirmation. For example, if you attempt to apply a poison to a weapon that already has a poison, the game will ask you to confirm the replacement. You can accept the replacement with ReplaceEnchant() or cancel the replacement with SpellStopTargeting().