3rd level of Complete Warrior's Swashbuckler class grants Insightful Strike:
...applies her Intelligence bonus (if any) as a bonus on damage rolls (in addition to any Strength bonus she may have) with any light weapon, as well as any other weapon that can be used with Weapon Finesse, such as a rapier, whip, or spiked chain....
4th level of Swordsage class from Tome of Battle grants Discipline Focus (insightful strike):
... you can add your Wisdom modifier as a bonus on damage rolls whenever you execute a strike from the chosen discipline...
There is also Shadow Blade feat from same book:
While you are in a Shadow Hand stance and attack with one of the discipline’s preferred weapons, you can add your Dexterity modifier as a bonus on melee damage for attacks made with the weapon.
Short sword is light weapon preferred by Shadow Hand discipline.
Build with 3 levels of Swashbuckler and 4 levels of Swordsage (specialized in Shadow Hand discipline) looks valid.
Does that mean that when executing Shadow Hand strike, armed with short sword, with Shadow Hand stance active, this character deals 1d6+STR+DEX+INT+WIS damage (not counting possible additional damage from strike)?