Log Message:
py-mercurial: updated to 4.8.2

This is a regularly-scheduled bugfix release containing following fixes:

1.1. commands
update: do not pass in user revspec as default destination

1.2. core
match: fix assertion for fileset with no context
revlog: catch delta base value under -1
revlog: catch revlog corruption in index_baserev
server: always close http socket if responding with an error
vfs: ensure closewrapbase fh doesn't escape by entering context manager

1.3. extensions
phabricator: properly encode boolean types in the request body

1.4. unsorted
windows: ensure mixedfilemodewrapper fd doesn't escape by entering context mgr
worker: do not swallow exception occurred in main process