localrepo: forcibly copy list of filecache keys
On Python 3, keys() is more like iterkeys(), so we got in trouble for
mutating the dict while we're iterating here. Since the list of caches
should be relatively small, work around this difference by just
forcing a copy of the key list.
https://bz.mercurial-scm.org/1877
$ hg init a
$ cd a
$ echo a > a
$ hg add a
$ hg ci -m 'a'
$ echo b > a
$ hg ci -m'b'
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg book main
$ hg book
* main 0:cb9a9f314b8b
$ echo c > c
$ hg add c
$ hg ci -m'c'
created new head
$ hg book
* main 2:d36c0562f908
$ hg heads
changeset: 2:d36c0562f908
bookmark: main
tag: tip
parent: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: c
changeset: 1:1e6c11564562
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: b
$ hg up 1e6c11564562
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
(leaving bookmark main)
$ hg merge main
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg book
main 2:d36c0562f908
$ hg ci -m'merge'
$ hg book
main 2:d36c0562f908
$ cd ..