A few changes:
* Include notes about git-2.24.0 changes
* Make it clearer that messing with the first parent could have
negative side-effects if the file_changes aren't also updated.
* Fix wrapping of a line that was too long.
Also, update the README.md:
* Note the upstream improvements made in (not yet released) git-2.24.0
Signed-off-by: Elijah Newren <newren@gmail.com>
Partial history rewrites were possible before with the (previously
hidden) --refs flag, but the defaults were wrong. That could be worked
around with the --source or --target flags, but that disabled --no-data
for fast-export and thus slowed things down, and also would require
overridding --replace-refs. And the defaults for --source and --target
may diverge further from what is wanted/needed for partial history
rewrites in the future.
So, add --partial as a first-class supported option with scary
documentation about how it permits mixing new and old history. Make
--refs imply that flag. Make the behavioral similarities (in regards to
which steps are skipped) between --source, --target, and --partial more
clear. Add relevant documentation to round it out.
Signed-off-by: Elijah Newren <newren@gmail.com>
Allow folks to periodically update the export of a live repo without
re-exporting from the beginning. This is a performance improvement, but
can also be important for collaboration. For example, for sensitivity
reasons, folks might want to export a subset of a repo and update the
export periodically. While this could be done by just re-exporting the
repository anew each time, there is a risk that the paths used to
specify the wanted subset might need to change in the future; making the
user verify that their paths (including globs or regexes) don't also
pick up anything from history that was previously excluded so that they
don't get a divergent history is not very user friendly. Allowing them
to just export stuff that is new since the last export works much better
for them.
Signed-off-by: Elijah Newren <newren@gmail.com>
