This affects heroes who can change their attack type from ranged to melee.

When you start an attack while in ranged form, and then you return to melee form during the attack animation, your attack will still use the ranged form projectile, but will count as a melee attack.

This means you can currently shoot dragon projectiles in his knight form, or use a ranged attack with Terrorblade while in melee form. All you have to do is time the attack so that the transformation spell expires during the attack animation.

Troll Warlord can do it all the time. He can just switch Berserker's Rage during attack animations, allowing him to perform instant melee attacks at great distance, or use melee effects with projectiles.

This could be fixed by making melee/ranged being decided upon completing the attack, instead of upon attack begin.