match: drop unnecessary adding of '' to set of dirs This breaks some tests for "rootfilesin:" in a pattern matcher even more, but that just shows how broken that case is. Differential Revision: https://phab.mercurial-scm.org/D6406

narrowcommands: drop unnecessary adding of '' for root directory It's now included by util.dirs(). Differential Revision: https://phab.mercurial-scm.org/D6405

copies: remove hack for adding root dir to util.dirs object Differential Revision: https://phab.mercurial-scm.org/D6404

util: make util.dirs() and util.finddirs() include root directory (API) This changes the behavior of test-origbackup-conflict.t so it no longer errors out when the backup path points to an existing file. Instead, it replaces the file by a directory. That seems reasonable to me. Differential Revision: https://phab.mercurial-scm.org/D6403

dirstate: drop workaround for '.' matching root directory The check was added in 31abcae33b4f (dirstate: do not ignore current directory '.' (issue 1078), 2008-04-05) to fix issue1078. Funnily enough, comment #2 on that issue mentions using '' instead of '.' to represent the root directory, just like my previous patch did. test-hgignore.t fails with this patch without the previous patch. Differential Revision: https://phab.mercurial-scm.org/D6402

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