match: use '' instead of '.' for root directory (API) I think '' is generally a better value for the root directory than '.' is. For example, os.path.join('', 'foo') => 'foo', while os.path.join('.', 'foo') => './foo'. This patch mostly makes it so we use '' internally in match.py. However, it also affects the API in visitdir(), visitchildrenset() and files(). The two former now also accept '' as input. I've updated the callers of these methods. I've also added a deprecation warning for passing '.' (for external callers). The only caller I could find that was affected by files() returning '' instead of '.' was in dirstate.walk(). I've updated that. The next few patches show some workarounds we can remove by using '' instead of '.'. Differential Revision: https://phab.mercurial-scm.org/D6401

dirstate: move special handling of files==['.'] together I think it makes it a little clearer to have the two conditions for files==['.'] near each other. Differential Revision: https://phab.mercurial-scm.org/D6400

convert: don't include file in "files" list if it's added in p2 If the file is from p2, we should clearly compare the flags to what they were in p2. Also note that manifest.flags('non-existent') unfortunately returns '' instead of erroring out. Differential Revision: https://phab.mercurial-scm.org/D6409