dirstate-v2: Reuse existing paths when appending to a data file
When writing a dirstate in v2 format by appending to an existing data file,
filenames / paths that are borrowed from the previous on-disk representation
can be reused.
Differential Revision: https://phab.mercurial-scm.org/D11096
#require test-repo jshint hg10
$ . "$TESTDIR/helpers-testrepo.sh"
run jshint on all tracked files ending in .js except vendored dependencies
$ cd "`dirname "$TESTDIR"`"
$ testrepohg locate 'set:**.js' \
> 2>/dev/null \
> | xargs jshint