Summary:
Add a config option `format.usetreestate`, which would turn on the new
treestate for new repos.
Treestate does not need manually maintaining "copymap", "otherparentset",
"nonnormalset". The one single tree is the source of truth of everything.
So some code like `copymap.pop` etc. are disabled on treestate path.
Reviewed By: markbt
Differential Revision: D7909175
fbshipit-source-id: 96a405fccd4099cefc152ec17204cb5407efbe7e
On a case-sensitive file system, files can be added with names that differ
only in case (a "case collision"). This would cause an error on case-insensitive
filesystems. A warning or error is now given for such collisions, depending on
the value of ui.portablefilenames ('warn', 'abort', or 'ignore'):
$ touch file File
$ hg add --config ui.portablefilenames=abort File
abort: possible case-folding collision for File
$ hg add File
warning: possible case-folding collision for File