largefiles: fix path handling for cp/mv (issue3516) Previously, a copy or a move of a largefile only worked if the cwd was the root of the repository. The first issue was that the destination path passed to os.mkdirs() chopped the absolute path to the standin after '.hglf/', which essentially created a path relative to the repository root. Similarly, the second issue was that the source and dest paths for copyfile() were relative to the repo root. This converts these three paths to absolute paths. Some notable issues, regardless of the directory in which the cp/mv is executed: 1) The copy is not being recorded in lfdirstate, but it is in dirstate for the standins. I'm not sure if this is by design (i.e. minimal info in lfdirstate). 2) status -C doesn't behave as expected. Using the testcase as an example: # after mv + ci $ hg status -C -v --rev '.^' # expected to see 'A' and ' ' lines too R dira\dirb\largefile $ hg status -C -v --rev '.^' foo/largefile # no output # expected to see 'A' and ' ' lines only $ hg status -C -v --rev '.^' foo/ # no output # expected to see 'A', ' ' and 'R' lines $ hg status -C -v --rev '.^' ./ # expected to see 'A' and ' ' lines too R dirb\largefile $ hg status -C -v --rev '.^' ../.hglf/dira/foo/largefile A ..\.hglf\dira\foo\largefile ..\.hglf\dira\dirb\largefile # no 'R' expected when new file is specified $ hg status -C -v --rev '.^' ../.hglf # OK A ..\.hglf\dira\foo\largefile ..\.hglf\dira\dirb\largefile R ..\.hglf\dira\dirb\largefile