dirstate: make dir collision logic faster - shortcircuit decpath if we haven't built the _dirs map - increment only for leafnodes of directory tree (this should make construction more like O(nlog n) than O(n^2))

#!/bin/sh

hg init

echo "Is there an error message when trying to diff non-existing files?"
hg diff not found

echo "Is there an error message when trying to add non-existing files?"
hg add not found