While I was looking at the conflict cleanup code, I looked over at
the tree cache code, since we clear the tree cache for each entry
that gets removed and there is some redundancy there. I made some
small tweaks to avoid extra calls to strchr and strlen in a few
circumstances.
Whenever a file is updated in the index, each tree leading towards it
needs to be invalidated. Provide the supporting function.
Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
