rust-filepatterns: allow overriding default syntax
This will be used when parsing pattern files other than .hgignore like the
sparse spec.
$ hg init test
$ cd test
$ hg debugbuilddag '+2'
$ hg phase --public 0
$ hg serve -p $HGPORT -d --pid-file=hg.pid -E errors.log
$ cat hg.pid >> $DAEMON_PIDS
$ cd ..
$ hg init test2
$ cd test2
$ hg incoming http://foo:xyzzy@localhost:$HGPORT/
comparing with http://foo:***@localhost:$HGPORT/
changeset: 0:1ea73414a91b
user: debugbuilddag
date: Thu Jan 01 00:00:00 1970 +0000
summary: r0
changeset: 1:66f7d451a68b
tag: tip
user: debugbuilddag
date: Thu Jan 01 00:00:01 1970 +0000
summary: r1
$ killdaemons.py
$ cd ..
$ hg -R test --config server.view=immutable serve -p $HGPORT -d --pid-file=hg.pid -E errors.log
$ cat hg.pid >> $DAEMON_PIDS
$ hg -R test2 incoming http://foo:xyzzy@localhost:$HGPORT/
comparing with http://foo:***@localhost:$HGPORT/
changeset: 0:1ea73414a91b
tag: tip
user: debugbuilddag
date: Thu Jan 01 00:00:00 1970 +0000
summary: r0
Check same result using `experimental.extra-filter-revs`
$ hg -R test --config experimental.extra-filter-revs='not public()' serve -p $HGPORT1 -d --pid-file=hg2.pid -E errors.log
$ cat hg2.pid >> $DAEMON_PIDS
$ hg -R test2 incoming http://foo:xyzzy@localhost:$HGPORT1/
comparing with http://foo:***@localhost:$HGPORT1/
changeset: 0:1ea73414a91b
tag: tip
user: debugbuilddag
date: Thu Jan 01 00:00:00 1970 +0000
summary: r0
$ hg -R test --config experimental.extra-filter-revs='not public()' debugupdatecache
$ ls -1 test/.hg/cache/
branch2-base%89c45d2fa07e
branch2-immutable%89c45d2fa07e
branch2-served
branch2-served%89c45d2fa07e
branch2-served.hidden%89c45d2fa07e
branch2-visible%89c45d2fa07e
branch2-visible-hidden%89c45d2fa07e
hgtagsfnodes1
rbc-names-v1
rbc-revs-v1
tags2
tags2-served%89c45d2fa07e
cleanup
$ cat errors.log
$ killdaemons.py