annotate README.rst @ 46834:535de0e34a79

rebase: filter out descendants of divergence-causing commits earlier

`hg rebase` treats obsolete commits differently depending what has
happened to the commit:

 1) Obsolete commit without non-obsolete successors: Skipped, and a
 note is printed ("it has no successor").

 2) Obsolete commit with a successor in the destination (ancestor of
 it): Skipped, and a note is printed ("already in destination").

 3) Obsolete commit with a successor in the rebase set: The commit and
 its descendants are skipped, and a note is printed ("not rebasing
 <commit> and its descendants as this would cause divergence"), unless
 `allowdivergence` config set.

 4) Obsolete commit with a successor elsewhere: Error ("this rebase
 will cause divergences"), unless `allowdivergence` config set.

Before this patch, we did all those checks up front, except for (3),
which was checked later. The later check consisted of two parts: 1)
filtering out of descendants, and 2) conditionally printing message if
the `allowdivergence` config was not set. This patch makes it so we do
the filtering early.

A consequence of filtering out divergence-causing commits earlier is
that we rebase commits in slightly different order, which has some
impact on tests.

Differential Revision: https://phab.mercurial-scm.org/D10249

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.