dirstate: handle missing backup file on restoration
This is the stable counter part to e358f6e0e50e.
Since 6.4 will stop writing undo.dirstate in some case (actually… at all), a
transaction created with 6.4 and recover/rolledback with 6.3 need to work to a
certain degreee. This changeset add the necessary bits so that we don't get a
traceback from 6..3 in this cases.
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install::
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing::
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.
Notes for packagers
===================
Mercurial ships a copy of the python-zstandard sources. This is used to
provide support for zstd compression and decompression functionality. The
module is not intended to be replaced by the plain python-zstandard nor
is it intended to use a system zstd library. Patches can result in hard
to diagnose errors and are explicitly discouraged as unsupported
configuration.