revlog: calculate base revisions iteratively
This is in preparation for generaldelta, where the revlog entry base field is
reinterpreted as the deltaparent. For that reason we also rename the base
function to chainbase.
Without generaldelta, performance is unaffected, but generaldelta will suffer
from this in _addrevision, since delta chains will be walked repeatedly.
A cache has been added to eliminate this problem completely.
$ unset HGUSER
$ EMAIL="My Name <myname@example.com>"
$ export EMAIL
$ hg init test
$ cd test
$ touch asdf
$ hg add asdf
$ hg commit -m commit-1
$ hg tip
changeset: 0:53f268a58230
tag: tip
user: My Name <myname@example.com>
date: Thu Jan 01 00:00:00 1970 +0000
summary: commit-1
$ unset EMAIL
$ echo 1234 > asdf
$ hg commit -u "foo@bar.com" -m commit-1
$ hg tip
changeset: 1:3871b2a9e9bf
tag: tip
user: foo@bar.com
date: Thu Jan 01 00:00:00 1970 +0000
summary: commit-1
$ echo "[ui]" >> .hg/hgrc
$ echo "username = foobar <foo@bar.com>" >> .hg/hgrc
$ echo 12 > asdf
$ hg commit -m commit-1
$ hg tip
changeset: 2:8eeac6695c1c
tag: tip
user: foobar <foo@bar.com>
date: Thu Jan 01 00:00:00 1970 +0000
summary: commit-1
$ echo 1 > asdf
$ hg commit -u "foo@bar.com" -m commit-1
$ hg tip
changeset: 3:957606a725e4
tag: tip
user: foo@bar.com
date: Thu Jan 01 00:00:00 1970 +0000
summary: commit-1
$ echo 123 > asdf
$ echo "[ui]" > .hg/hgrc
$ echo "username = " >> .hg/hgrc
$ hg commit -m commit-1
abort: no username supplied (see "hg help config")
[255]
$ rm .hg/hgrc
$ hg commit -m commit-1 2>&1
No username found, using '[^']*' instead (re)
$ echo space > asdf
$ hg commit -u ' ' -m commit-1
transaction abort!
rollback completed
abort: empty username!
[255]