Nested if statements without else conditions

gistfile1.rb

if a || b == d || c != n  # lets check a bunch of conditions
  if m <= p && a > n      # we passed! ok, let's check some more
    puts 'YAY'            # we passed again!
  end                     # I guess that's all we really needed
end                       # fine!

For the record, I am not saying this is wrong (or right). I (suppose I) can see how it can improve readability. It just annoys me to see two if conditionals stacked on each other when no negative conditions exist

I agree, and if the conditional logic is that complex, why not extract it into a method? Here's another that boiled my blood:

a = 0 unless a == 0

though when I first saw this, it was written in PL/1:

if a <> 0 then do;
  a = 0;
end;

though to be fair, this was from a programmer who still used GOTOs at the time. The worst was when they would GOTO into or out of the middle of a subroutine, no one could ever explain to me what happened to the call stack when this happened... I'm so glad it's not the early 90s anymore.