Merge branch 'jc/read-tree'

* jc/read-tree:
  t6022: ignoring untracked files by merge-recursive when they do not matter
  merge-recursive: adjust to loosened "working file clobbered" check
  merge-recursive: make a few functions static.
  merge-recursive: use abbreviated commit object name.
  merge: loosen overcautious "working file will be lost" check.

diff --cc merge-recursive.c
Simple merge