Assume there are only two players in the pot, the stack size of Hero is $10, Villain $5. Hero goes all-in post-flop, villain calls. Rake 5%, is the rake
$15 * 0.05 = $0.75 ,
$10 * 0.05 = $0.5 ?
This is a very common and frequently happening situation. For me, the latter makes more sense. Otherwise, Hero would have to type in the exact amount of what Villain has left to go effectively all-in with minimum rake.