Teaches 'git commit --amend' to copy notes.  The catch is that this
must also be guarded by --no-post-rewrite, which we use to prevent
--amend from copying notes during a rebase -i 'edit'/'reword'.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Luckily, all the support already happens to be there.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Implement helper functions to load the rewriting config, and to
actually copy the notes.  Also document the config.

Secondly, also implement an undocumented --for-rewrite=<cmd> option to
'git notes copy' which is used like --stdin, but also puts the
configuration for <cmd> into effect.  It will be needed to support the
copying in git-rebase.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Acked-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This implements a mass-copy command that takes a sequence of lines in
the format

  <from-sha1> SP <to-sha1> [ SP <rest> ] LF

on stdin, and copies each <from-sha1>'s notes to the <to-sha1>.  The
<rest> is ignored.  The intent, of course, is that this can read the
same input that the 'post-rewrite' hook gets.

The copy_note() function is exposed for everyone's and in particular
the next commit's use.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Acked-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Aside from the same issue that rebase also has (remembering the
original commit across a conflict resolution), rebase -i brings an
extra twist: We need to defer writing the rewritten list in the case
of {squash,fixup} because their rewritten result should be the last
commit in the squashed group.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We have to deal with two separate code paths: a normal rebase, which
actually goes through git-am; and rebase {-m|-s}.

The only small issue with both is that they need to remember the
original sha1 across a possible conflict resolution.  rebase -m
already puts this information in $dotest/current, and we just
introduce a similar file for git-am.

Note that in git-am, the hook really only runs when coming from
git-rebase: the code path that sets the $dotest/original-commit file
is guarded by a test for $dotest/rebasing.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The rough structure of run_rewrite_hook() comes from
run_receive_hook() in receive-pack.

We introduce a --no-post-rewrite option and use it to avoid the hook
when called from git-rebase -i 'edit'.  The next patch will add full
support in git-rebase, and we only want to invoke the hook once.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This defines the behaviour of the post-rewrite hook support, which
will be implemented in the following patches.

We deliberately do not document how often the hook will be invoked per
rewriting command, but the interface is designed to keep that at
"once".  This would currently not matter too much, since both rebase
and filter-branch are shellscripts and spawn many processes anyway.
However, when a fast sequencer in C is implemented, it will be
beneficial to only have to run the hook once.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

With this patch, you can set notes.displayRef to a glob that points at
your favourite notes refs, e.g.,

[notes]
	displayRef = refs/notes/*

Then git-log and friends will show notes from all trees.

Thanks to Junio C Hamano for lots of feedback, which greatly
influenced the design of the entire series and this commit in
particular.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Acked-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Acked-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is useful for keeping notes to objects that are being rewritten by e.g.
'git commit --amend', 'git rebase', or 'git cherry-pick'.

"git notes copy <from> <to>" is in practice equivalent to
"git notes add -C $(git notes list <from>) <to>", although it is somewhat
more convenient for regular users.

"git notes copy" takes the same -f option as "git add", to overwrite existing
notes at the target (instead of aborting with an error message).

If the <from>-object has no notes, "git notes copy" will abort with an error
message.

The patch includes tests verifying correct behaviour of the new subcommand.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is in preparation of future patches that add additional subcommands.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Inspired by the -c/-C options to "git commit", we teach these options to
"git notes add/append" to allow reuse of note objects.

With this patch in place, it is now easy to copy or move notes between
objects. For example, to copy object A's notes to object B:
	git notes add [-f] -C $(git notes list A) B
To move instead of copying, you simply remove the notes from the source
object afterwards, e.g.:
	git notes remove A

The patch includes tests verifying correct behaviour of the new functionality.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

By moving the -F option handling into a separate function (parse_file_arg),
we can start allowing several -F options, and mixed usage of -m and -F
options. Each -m/-F given appends to the note message, in the order they are
given on the command-line.

The patch includes tests verifying correct behaviour of the new functionality.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The semantics for "git notes edit -m/-F" overlap with those for
"git notes add -f", and the behaviour (i.e. overwriting existing
notes with the given message/file) is more intuitively captured
by (and better documented with) "git notes add -f".
Suggested-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

"git notes append" is equivalent to "git notes edit" except that instead
of editing existing notes contents, you can only append to it. This is
useful for quickly adding annotations like e.g.:
	git notes append -m "Acked-by: A U Thor <author@example.com>"

"git notes append" takes the same -m/-F options as "git notes add".

If there is no existing note to append to, "git notes append" is identical
to "git notes add" (i.e. it adds a new note).

The patch includes tests verifying correct behaviour of the new subcommand.
Suggested-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

"git notes add" is identical to "git notes edit" except that instead of
editing existing notes for a given object, you can only add notes to an
object that currently has none. If "git notes add" finds existing notes
for the given object, the addition is aborted. However, if the new
-f/--force option is used, "git notes add" will _overwrite_ the existing
notes with the new notes contents.

If there is no existing notes for the given object. "git notes add" is
identical to "git notes edit" (i.e. it adds a new note).

The patch includes tests verifying correct behaviour of the new subcommand.
Suggested-by: NJoey Hess <joey@kitenet.net>
Improved-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

"git notes list" will list all note objects in the current notes ref (in the
format "<note object> <annotated object>"). "git notes list <object>" will
list the note object associated with the given <object>, or fail loudly if
the given <object> has no associated notes.

If no arguments are given to "git notes", it defaults to the "list"
subcommand. This is for pseudo-compatibility with "git tag" and "git branch".

The patch includes tests verifying correct behaviour of the new subcommand.
Suggested-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Notes can annotate arbitrary objects (not only commits), but this is not
reflected in the current documentation.

This patch rewrites the git-notes documentation to talk about 'objects'
instead of 'commits'. However, the discussion on commit notes and how
they are displayed by 'git log' is largely preserved.

Finally, I add myself to the Author/Documentation credits, since most of
the lines in the git-notes code and docs are blamed on me.

Cc: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

"git notes prune" will remove all notes that annotate unreachable/non-
existing objects.

The patch includes tests verifying correct behaviour of the new subcommand.
Suggested-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When an object is made unreachable by Git, any notes that annotate that object
are not automagically made unreachable, since all notes are always trivially
reachable from a notes ref. In order to remove notes for non-existing objects,
we therefore need to add functionality for traversing the notes tree and
explicitly removing references to notes that annotate non-reachable objects.
Thus the notes objects themselves also become unreachable, and are removed
by a later garbage collect.

prune_notes() performs this traversal (by using for_each_note() internally),
and removes the notes in question from the notes tree.

Note that the effect of prune_notes() is not persistent unless a subsequent
call to write_notes_tree() is made.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Using "git notes remove" is equivalent to specifying an empty note message.

The patch includes tests verifying correct behaviour of the new subcommand.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When the result of editing a note is an empty string, the associated note
entry should be deleted from the notes tree.

This allows deleting notes by invoking either "git notes -m ''" or
"git notes -F /dev/null".
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The note tree structure allows for non-note entries to coexist with note
entries in a notes tree. Although we certainly expect there to be very
few non-notes in a notes tree, we should still support them to a certain
degree.

This patch teaches the notes code to preserve non-notes when updating the
notes tree with write_notes_tree(). Non-notes are not affected by fanout
restructuring.

For non-notes to be handled correctly, we can no longer allow subtree
entries that do not match the fanout structure produced by the notes code
itself. This means that fanouts like 4/36, 6/34, 8/32, 4/4/32, etc. are
no longer recognized as note subtrees; only 2-based fanouts are allowed
(2/38, 2/2/36, 2/2/2/34, etc.). Since the notes code has never at any point
_produced_ non-2-based fanouts, it is highly unlikely that this change will
cause problems for anyone.

The patch also adds some tests verifying the correct handling of non-notes
in a notes tree.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add a test verifying that the notes code automatically restructures the
notes tree into a deeper fanout level, when many notes are added with
"git notes".
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Adds a testcase verifying that git-notes works successfully on
tree, blob, and tag objects.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The builtin-ification includes some minor behavioural changes to the
command-line interface: It is no longer allowed to mix the -m and -F
arguments, and it is not allowed to use multiple -F options.

As part of the builtin-ification, we add the commit_notes() function
to the builtin API. This function (together with the notes.h API) can
be easily used from other builtins to manipulate the notes tree.

Also includes needed changes to t3301.

This patch has been improved by the following contributions:
- Stephen Boyd: Use die() instead of fprintf(stderr, ...) followed by exit(1)

Cc: Stephen Boyd <bebarino@gmail.com>
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When adding a note to an object that already has an existing note, the
current solution is to concatenate the contents of the two notes. However,
the caller may instead wish to _overwrite_ the existing note with the new
note, or maybe even _ignore_ the new note, and keep the existing one. There
might also be other ways of combining notes that are only known to the
caller.

Therefore, instead of unconditionally concatenating notes, we let the caller
specify how to combine notes, by passing in a pointer to a function for
combining notes. The caller may choose to implement its own function for
notes combining, but normally one of the following three conveniently
supplied notes combination functions will be sufficient:

- combine_notes_concatenate() combines the two notes by appending the
  contents of the new note to the contents of the existing note.

- combine_notes_overwrite() replaces the existing note with the new note.

- combine_notes_ignore() keeps the existing note, and ignores the new note.

A combine_notes function can be passed to init_notes() to choose a default
combine_notes function for that notes tree. If NULL is given, the notes tree
falls back to combine_notes_concatenate() as the ultimate default.

A combine_notes function can also be passed directly to add_note(), to
control the notes combining behaviour for a note addition in particular.
If NULL is passed, the combine_notes function registered for the given
notes tree is used.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The new struct notes_tree encapsulates access to a specific notes tree.
It is provided to allow callers to make use of several different notes trees
simultaneously.

A struct notes_tree * parameter is added to every function in the notes API.
In all cases, NULL can be passed, in which case the fallback "default" notes
tree (default_notes_tree) is used.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Uses for_each_note() to traverse the notes tree, and produces tree
objects on the fly representing the "on-disk" version of the notes
tree with appropriate fanout.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This includes a first attempt at creating an optimal fanout scheme (which
is calculated on-the-fly, while traversing).
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Created by a simple cleanup and rename of lookup_notes().
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This includes adding internal functions for maintaining a healthy notes tree
structure after removing individual notes.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Created by a simple refactoring of initialize_notes().

Also add a new 'flags' parameter, which is a bitwise combination of notes
initialization flags. For now, there is only one flag - NOTES_INIT_EMPTY -
which indicates that the notes tree should not auto-load the contents of
the given (or default) notes ref, but rather should leave the notes tree
initialized to an empty state. This will become useful in the future when
manipulating the notes tree through the notes API.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There is really no reason why only commit objects can be annotated. By
changing the struct commit parameter to get_commit_notes() into a sha1 we
gain the ability to annotate any object type. To reflect this in the function
naming as well, we rename get_commit_notes() to format_note().

This patch also fixes comments and variable names throughout notes.c as a
consequence of the removal of the unnecessary 'commit' restriction.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>