rust-cpython: add panicking version of borrow_mut() and use it
The original borrow_mut() is renamed to try_borrow_mut().
Since leak_immutable() no longer incref the borrow count, the caller should
know if the underlying value is borrowed or not. No Python world is involved.
That's why we can simply use the panicking borrow_mut().
$ 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