When doing a reflog walk, we use the commit's date to
do any date limiting. In earlier versions of Git, this could
lead to nonsense results, since a skipped commit would
truncate the traversal. So a sequence like:
git commit ...
git checkout week-old-branch
git checkout -
git log -g --since=1.day.ago
would stop at the week-old-branch, even though the "git
commit" entry further back is still interesting.
As of the prior commit, which uses a parent-less traversal
of the reflog, you get the whole reflog minus any commits
whose dates do not match the specified options. This is
arguably useful, as you could scan the reflogs for commits
that originated in a certain range.
But more likely a user doing a reflog walk wants to limit
based on the reflog entries themselves. You can simulate
--until with:
git log -g @{1.day.ago}
but there's no way to ask Git to traverse only back to a
certain date. E.g.:
# show me reflog entries from the past day
git log -g --since=1.day.ago
This patch teaches the revision machinery to prefer the
reflog entry dates to the commit dates when doing a reflog
walk. Technically this is a change in behavior that affects
plumbing, but the previous behavior was so buggy that it's
unlikely anyone was relying on it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The reflog-walk system works by putting a ref's tip into the
pending queue, and then "traversing" the reflog by
pretending that the parent of each commit is the previous
reflog entry.
This causes a number of user-visible oddities, as documented
in t1414 (and the commit message which introduced it). We
can fix all of them in one go by replacing the fake-reflog
system with a much simpler one: just keeping a list of
reflogs to show, and walking through them entry by entry.
The implementation is fairly straight-forward, but there are
a few items to note:
1. We obviously must skip calling add_parents_to_list()
when we are traversing reflogs, since we do not want to
walk the original parents at all. As a result, we must call
try_to_simplify_commit() ourselves.
There are other parts of add_parents_to_list() we skip,
as well, but none of them should matter for a reflog
traversal:
- We do not allow UNINTERESTING commits, nor
symmetric ranges (and we bail when these are used
with "-g").
- Using --source makes no sense, since we aren't
traversing. The reflog selector shows the same
information with more detail.
- Using --first-parent is still sensible, since you
may want to see the first-parent diff for each
entry. But since we're not traversing, we don't
need to cull the parent list here.
2. Since we now just walk the reflog entries themselves,
rather than starting with the ref tip, we now look at
the "new" field of each entry rather than the "old"
(i.e., we are showing entries, not faking parents).
This removes all of the tricky logic around skipping
past root commits.
But note that we have no way to show an entry with the
null sha1 in its "new" field (because such a commit
obviously does not exist). Normally this would not
happen, since we delete reflogs along with refs, but
there is one special case. When we rename the currently
checked out branch, we write two reflog entries into
the HEAD log: one where the commit goes away, and
another where it comes back.
Prior to this commit, we show both entries with
identical reflog messages. After this commit, we show
only the "comes back" entry. See the update in t3200
which demonstrates this.
Arguably either is fine, as the whole double-entry
thing is a bit hacky in the first place. And until a
recent fix, we truncated the traversal in such a case
anyway, which was _definitely_ wrong.
3. We show individual reflogs in order, but choose which
reflog to show at each stage based on which has the
most recent timestamp. This interleaves the output
from multiple reflogs based on date order, which is
probably what you'd want with limiting like "-n 30".
Note that the implementation aims for simplicity. It
does a linear walk over the reflog queue for each
commit it pulls, which may perform badly if you
interleave an enormous number of reflogs. That seems
like an unlikely use case; if we did want to handle it,
we could probably keep a priority queue of reflogs,
ordered by the timestamp of their current tip entry.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When git-rev-list sees no pending commits, it shows a usage
message. This works even when reflog-walking is requested,
because the reflog-walk code currently puts the reflog tips
into the pending queue.
In preparation for refactoring the reflog-walk code, let's
explicitly check whether we have any reflogs to walk. For
now this is a noop, but the existing reflog tests will make
sure that it kicks in after the refactoring. Likewise, we'll
add a test that "rev-list -g" without specifying any reflogs
continues to fail (so that we know our check does not kick
in too aggressively).
Note that the implementation needs to go into its own
sub-function, as the walk code does not expose its innards
outside of reflog-walk.c.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In preparation for adding date modes that may carry extra
information beyond the mode itself, this patch converts the
date_mode enum into a struct.
Most of the conversion is fairly straightforward; we pass
the struct as a pointer and dereference the type field where
necessary. Locations that declare a date_mode can use a "{}"
constructor. However, the tricky case is where we use the
enum labels as constants, like:
show_date(t, tz, DATE_NORMAL);
Ideally we could say:
show_date(t, tz, &{ DATE_NORMAL });
but of course C does not allow that. Likewise, we cannot
cast the constant to a struct, because we need to pass an
actual address. Our options are basically:
1. Manually add a "struct date_mode d = { DATE_NORMAL }"
definition to each caller, and pass "&d". This makes
the callers uglier, because they sometimes do not even
have their own scope (e.g., they are inside a switch
statement).
2. Provide a pre-made global "date_normal" struct that can
be passed by address. We'd also need "date_rfc2822",
"date_iso8601", and so forth. But at least the ugliness
is defined in one place.
3. Provide a wrapper that generates the correct struct on
the fly. The big downside is that we end up pointing to
a single global, which makes our wrapper non-reentrant.
But show_date is already not reentrant, so it does not
matter.
This patch implements 3, along with a minor macro to keep
the size of the callers sane.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Gives a better DWIM behaviour for --pretty=format:%gd, "stash list", and
"log -g", depending on how the starting point ("master" vs "master@{0}" vs
"master@{now}") and date formatting options (e.g. "--date=iso") are given
on the command line.
By Jeff King (4) and Junio C Hamano (1)
* jk/maint-reflog-walk-count-vs-time:
reflog-walk: tell explicit --date=default from not having --date at all
reflog-walk: always make HEAD@{0} show indexed selectors
reflog-walk: clean up "flag" field of commit_reflog struct
log: respect date_mode_explicit with --format:%gd
t1411: add more selector index/date tests
Introduction of opt->date_mode_explicit was a step in the right direction,
but lost that crucial bit at the very end of the callchain, and the callee
could not tell an explicitly specified "I want *date* but in default format"
from the built-in default value passed when there was no --date specified.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When doing a reflog walk, you can get some information about
the reflog (such as the subject line), but not the identity
information (i.e., name and email).
Let's make those available, mimicing the options for author
and committer identity.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add three new --pretty=format escapes:
%gD long reflog descriptor (e.g. refs/stash@{0})
%gd short reflog descriptor (e.g. stash@{0})
%gs reflog message
This is achieved by passing down the reflog info, if any, inside the
pretty_print_context struct.
We use the newly refactored get_reflog_selector(), and give it some
extra functionality to extract a shortened ref. The shortening is
cached inside the commit_reflogs struct; the only allocation of it
happens in read_complete_reflog(), where it is initialised to 0. Also
add another helper get_reflog_message() for the message extraction.
Note that the --format="%h %gD: %gs" tests may not work in real
repositories, as the --pretty formatter doesn't know to leave away the
": " on the last commit in an incomplete (because git-gc removed the
old part) reflog. This equivalence is nevertheless the main goal of
this patch.
Thanks to Jeff King for reviews, the %gd testcase and documentation.
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The multiline reflog format (e.g., as shown by "git log -g")
will show HEAD@{<date>} rather than HEAD@{<count>} in two
situations:
1. If the user gave branch@{<date>} syntax to specify the
reflog
2. If the user gave a --date=<format> specifier
It uses the "normal" date format in case 1, and the
user-specified format in case 2.
The oneline reflog format (e.g., "git reflog show" or "git
log -g --oneline") will show the date in the same two
circumstances. However, it _always_ shows the date as a
relative date, and it always ignores the timezone.
In case 2, it seems ridiculous to trigger the date but use a
format totally different from what the user requested.
For case 1, it is arguable that the user might want to see
the relative date by default; however, the multiline version
shows the normal format.
This patch does three things:
- refactors the "relative_date" parameter to
show_reflog_message to be an actual date_mode enum,
since this is how it is used (it is passed to show_date)
- uses the passed date_mode parameter in the oneline
format (making it consistent with the multiline format)
- does not ignore the timezone parameter in oneline mode
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When asking "git log -g --all", clearly you want to see only those refs
that do have reflogs, but you do not want it to fail, either.
So instead of die()ing, complain about it, but move on to the other refs.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you say "git log -g --relative-date", it is very likely that
you want to see the reflog names in terms of a relative date.
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
When called with "--walk-reflogs", as long as there are reflogs
available, the walker will take this information into account, rather
than the parent information in the commit object.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
