Excerpt from [Git 2.22 Release Notes][1]:

> Updates since v2.21
> -------------------
>
> Backward compatibility note
>
>  * The filter specification "--filter=sparse:path=<path>" used to
>    create a lazy/partial clone has been removed.  Using a blob that is
>    part of the project as sparse specification is still supported with
>    the "--filter=sparse:oid=<blob>" option.
>
> UI, Workflows & Features
>
>  * "git checkout --no-overlay" can be used to trigger a new mode of
>    checking out paths out of the tree-ish, that allows paths that
>    match the pathspec that are in the current index and working tree
>    and are not in the tree-ish.
>
>  * The %(trailers) formatter in "git log --format=..."  now allows to
>    optionally pick trailers selectively by keyword, show only values,
>    etc.
>
>  * Four new configuration variables {author,committer}.{name,email}
>    have been introduced to override user.{name,email} in more specific
>    cases.
>
>  * Command-line completion (in contrib/) learned to tab-complete the
>    "git submodule absorbgitdirs" subcommand.
>
>  * "git branch" learned a new subcommand "--show-current".
>
>  * Output from "diff --cc" did not show the original paths when the
>    merge involved renames.  A new option adds the paths in the
>    original trees to the output.
>
>  * The command line completion (in contrib/) has been taught to
>    complete more subcommand parameters.
>
>  * The final report from "git bisect" used to show the suspected
>    culprit using a raw "diff-tree", with which there is no output for
>    a merge commit.  This has been updated to use a more modern and
>    human readable output that still is concise enough.
>
>  * "git rebase --rebase-merges" replaces its old "--preserve-merges"
>    option; the latter is now marked as deprecated.
>
>  * Error message given while cloning with --recurse-submodules has
>    been updated.
>
>  * The completion helper code now pays attention to repository-local
>    configuration (when available), which allows --list-cmds to honour
>    a repository specific setting of completion.commands, for example.
>
>  * "git mergetool" learned to offer Sublime Merge (smerge) as one of
>    its backends.
>
>  * A new hook "post-index-change" is called when the on-disk index
>    file changes, which can help e.g. a virtualized working tree
>    implementation.
>
>  * "git difftool" can now run outside a repository.
>
>  * "git checkout -m <other>" was about carrying the differences
>    between HEAD and the working-tree files forward while checking out
>    another branch, and ignored the differences between HEAD and the
>    index.  The command has been taught to abort when the index and the
>    HEAD are different.
>
>  * A progress indicator has been added to the "index-pack" step, which
>    often makes users wait for completion during "git clone".
>
>  * "git submodule" learns "set-branch" subcommand that allows the
>    submodule.*.branch settings to be modified.
>
>  * "git merge-recursive" backend recently learned a new heuristics to
>    infer file movement based on how other files in the same directory
>    moved.  As this is inherently less robust heuristics than the one
>    based on the content similarity of the file itself (rather than
>    based on what its neighbours are doing), it sometimes gives an
>    outcome unexpected by the end users.  This has been toned down to
>    leave the renamed paths in higher/conflicted stages in the index so
>    that the user can examine and confirm the result.
>
>  * "git tag" learned to give an advice suggesting it might be a
>    mistake when creating an annotated or signed tag that points at
>    another tag.
>
>  * The "git pack-objects" command learned to report the number of
>    objects it packed via the trace2 mechanism.
>
>  * The list of conflicted paths shown in the editor while concluding a
>    conflicted merge was shown above the scissors line when the
>    clean-up mode is set to "scissors", even though it was commented
>    out just like the list of updated paths and other information to
>    help the user explain the merge better.
>
>  * The trace2 tracing facility learned to auto-generate a filename
>    when told to log to a directory.
>
>  * "git clone" learned a new --server-option option when talking over
>    the protocol version 2.
>
>  * The connectivity bitmaps are created by default in bare
>    repositories now; also the pathname hash-cache is created by
>    default to avoid making crappy deltas when repacking.
>
>  * "git branch new A...B" and "git checkout -b new A...B" have been
>    taught that in their contexts, the notation A...B means "the merge
>    base between these two commits", just like "git checkout A...B"
>    detaches HEAD at that commit.
>
>  * Update "git difftool" and "git mergetool" so that the combinations
>    of {diff,merge}.{tool,guitool} configuration variables serve as
>    fallback settings of each other in a sensible order.
>
>  * The "--dir-diff" mode of "git difftool" is not useful in "--no-index"
>    mode; they are now explicitly marked as mutually incompatible.
>
> […]

[1]: https://lkml.org/lkml/2019/6/7/1177
[2]: https://github.blog/2019-06-07-highlights-from-git-2-22/