read_revisions_from_stdin() has passed pointers to its read buffer
down to handle_revision_arg() since its inception way back in 42cabc34
(Teach rev-list an option to read revs from the standard input.,
2006-09-05).  Even back then, this was a bug: through
add_pending_object, the argument was recorded in the object_array's
'name' field.

Fix it by making a copy whenever read_revisions_from_stdin() passes an
argument down the callchain.  The other caller runs handle_revision_arg()
on argv[], where it would be redundant to make a copy.
Signed-off-by: NThomas Rast <trast@inf.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Our "grep" allows complex boolean expressions to be formed to match
each individual line with operators like --and, '(', ')' and --not.
Introduce the "--debug" option to show the parse tree to help people
who want to debug and enhance it.

Also "log" learns "--grep-debug" option to do the same.  The command
line parser to the log family is a lot more limited than the general
"git grep" parser, but it has special handling for header matching
(e.g. "--author"), and a parse tree is valuable when working on it.

Note that "--all-match" is *not* any individual node in the parse
tree.  It is an instruction to the evaluator to check all the nodes
in the top-level backbone have matched and reject a document as
non-matching otherwise.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When 'git log' is passed the --no-walk option, no revision walk takes
place, naturally. Perhaps somewhat surprisingly, however, the provided
revisions still get sorted by commit date. So e.g 'git log --no-walk
HEAD HEAD~1' and 'git log --no-walk HEAD~1 HEAD' give the same result
(unless the two revisions share the commit date, in which case they
will retain the order given on the command line). As the commit that
introduced --no-walk (8e64006e (Teach revision machinery about
--no-walk, 2007-07-24)) points out, the sorting is intentional, to
allow things like

 git log --abbrev-commit --pretty=oneline --decorate --all --no-walk

to show all refs in order by commit date.

But there are also other cases where the sorting is not wanted, such
as

 <command producing revisions in order> |
       git log --oneline --no-walk --stdin

To accomodate both cases, leave the decision of whether or not to sort
up to the caller, by allowing --no-walk={sorted,unsorted}, defaulting
to 'sorted' for backward-compatibility reasons.
Signed-off-by: NMartin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Either end of revision range operator can be omitted to default to HEAD,
as in "origin.." (what did I do since I forked) or "..origin" (what did
they do since I forked).  But the current parser interprets ".."  as an
empty range "HEAD..HEAD", and worse yet, because ".." does exist on the
filesystem, we get this annoying output:

  $ cd Documentation/howto
  $ git log .. ;# give me recent commits that touch Documentation/ area.
  fatal: ambiguous argument '..': both revision and filename
  Use '--' to separate filenames from revisions

Surely we could say "git log ../" or even "git log -- .." to disambiguate,
but we shouldn't have to.
Helped-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

diff_setup_done() has historically returned an error code, but lost
the last nonzero return in 943d5b73 (allow diff.renamelimit to be set
regardless of -M/-C, 2006-08-09).  The callers were in a pretty
confused state: some actually checked for the return code, and some
did not.

Let it return void, and patch all callers to take this into account.
This conveniently also gets rid of a handful of different(!) error
messages that could never be triggered anyway.

Note that the function can still die().
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The diff code represents paths using the diff_filespec
struct. This struct has a sha1 to represent the sha1 of the
content at that path, as well as a sha1_valid member which
indicates whether its sha1 field is actually useful. If
sha1_valid is not true, then the filespec represents a
working tree file (e.g., for the no-index case, or for when
the index is not up-to-date).

The diff_filespec is only used internally, though. At the
interfaces to the diff subsystem, callers feed the sha1
directly, and we create a diff_filespec from it. It's at
that point that we look at the sha1 and decide whether it is
valid or not; callers may pass the null sha1 as a sentinel
value to indicate that it is not.

We should not typically see the null sha1 coming from any
other source (e.g., in the index itself, or from a tree).
However, a corrupt tree might have a null sha1, which would
cause "diff --patch" to accidentally diff the working tree
version of a file instead of treating it as a blob.

This patch extends the edges of the diff interface to accept
a "sha1_valid" flag whenever we accept a sha1, and to use
that flag when creating a filespec. In some cases, this
means passing the flag through several layers, making the
code change larger than would be desirable.

One alternative would be to simply die() upon seeing
corrupted trees with null sha1s. However, this fix more
directly addresses the problem (while bogus sha1s in a tree
are probably a bad thing, it is really the sentinel
confusion sending us down the wrong code path that is what
makes it devastating). And it means that git is more capable
of examining and debugging these corrupted trees. For
example, you can still "diff --raw" such a tree to find out
when the bogus entry was introduced; you just cannot do a
"--patch" diff (just as you could not with any other
corrupted tree, as we do not have any content to diff).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

During a revision traversal in which --max-count has been
specified, we decrement a counter for each revision returned
by get_revision. When it hits 0, we typically return NULL
(the exception being if we still have boundary commits to
show).

However, before we check the counter, we call get_revision_1
to get the next commit. This might involve looking at a
large number of commits if we have restricted the traversal
(e.g., we might traverse until we find the next commit whose
diff actually matches a pathspec).

There's no need to make this get_revision_1 call when our
counter runs out. If we are not in --boundary mode, we will
just throw away the result and immediately return NULL. If
we are in --boundary mode, then we will still throw away the
result, and then start showing the boundary commits.
However, as git_revision_1 does not impact the boundary
list, it should not have an impact.

In most cases, avoiding this work will not be especially
noticeable. However, in some cases, it can make a big
difference:

  [before]
  $ time git rev-list -1 origin Documentation/RelNotes/1.7.11.2.txt
  8d141a1d

  real    0m0.301s
  user    0m0.280s
  sys     0m0.016s

  [after]
  $ time git rev-list -1 origin Documentation/RelNotes/1.7.11.2.txt
  8d141a1d

  real    0m0.010s
  user    0m0.008s
  sys     0m0.000s

Note that the output is produced almost instantaneously in
the first case, and then git uselessly spends a long time
looking for the next commit to touch that file (but there
isn't one, and we traverse all the way down to the roots).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add a field to setup_revision_opt structure and allow these callers
to tell the setup_revisions command parsing machinery that short SHA1
it encounters are meant to name committish.

This step does not go all the way to connect the setup_revisions()
to sha1_name.c yet.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The existing "cant_be_filename" that tells the function that the
caller knows the arg is not a path (hence it does not have to be
checked for absense of the file whose name matches it) is made into
a bit in the flag word.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Many callers know that the user meant to name a committish by
syntactical positions where the object name appears.  Calling this
function allows the machinery to disambiguate shorter-than-unique
abbreviated object names between committish and others.

Note that this does NOT error out when the named object is not a
committish. It is merely to give a hint to the disambiguation
machinery.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The function takes user input string and returns the object name
(binary SHA-1) with mode bits and path when the object was looked
up in a tree.

Additionally give hints to help disambiguation of abbreviated object
names when the caller knows what it is looking for.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There are only two callers, and they will benefit from being able to
pass disambiguation hints to underlying get_sha1_with_context() API
once it happens.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

verify_filename() can be called in two different contexts. Either we
just tried to interpret a string as an object name, and it fails, so
we try looking for a working tree file (i.e. we finished looking at
revs that come earlier on the command line, and the next argument
must be a pathname), or we _know_ that we are looking for a
pathname, and shouldn't even try interpreting the string as an
object name.

For example, with this change, we get:

  $ git log COPYING HEAD:inexistant
  fatal: HEAD:inexistant: no such path in the working tree.
  Use '-- <path>...' to specify paths that do not exist locally.
  $ git log HEAD:inexistant
  fatal: Path 'inexistant' does not exist in 'HEAD'
Signed-off-by: NMatthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The simplify_merges() function needs to look at all history chain to
find the closest ancestor that is relevant after the simplification,
but after --first-parent traversal, side parents haven't been marked
for relevance (they are irrelevant by definition due to the nature
of first-parent-only traversal) nor culled from the parents list of
resulting commits.

We cannot simply remove these side parents from the parents list, as
the output phase still wants to see the parents.  Instead, teach
simplify_one() and its callees to ignore the later parents.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Among the three similar-looking loops that walk singly linked
commit_list, the first one is only peeking and the same list is
later used for real work.  Leave a comment not to mistakenly
free its elements there.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The code internally runs sort_in_topo_order() already; it is more clear
to spell it out in the option parsing phase, instead of adding a special
case in simplify_merges() function.

By using commit_list_insert(), we added new items to the top of the
list and, since this is not the order we want, reversed it afterwards.
Simplify this process by adding new items at the bottom instead,
getting rid of the reversal step.
Signed-off-by: NRene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If a commit-ish passed to cherry-pick or revert happens to have a file
of the same name, git complains that the argument is ambiguous and
advises to use '--'. To make things worse, the '--' argument is removed
by parse_options, und so passing '--' has no effect.

Instead, always interpret cherry-pick/revert arguments as revisions.
Signed-off-by: NClemens Buchacher <drizzd@aon.at>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Speed up prepare_revision_walk() by adding commits without sorting
to the commit_list and at the end sort the list in one go.  Thanks
to mergesort() working behind the scenes, this is a lot faster for
large numbers of commits than the current insert sort.

Also introduce and use commit_list_reverse(), to keep the ordering
of commits sharing the same commit date unchanged.  That's because
commit_list_insert_by_date() sorts commits with descending date,
but adds later entries with the same date entries last, while
commit_list_insert() always inserts entries at the top.  The
following commit_list_sort_by_date() keeps the order of entries
sharing the same date.

Jeff's test case, in a repo with lots of refs, was to run:

  # make a new commit on top of HEAD, but not yet referenced
  sha1=`git commit-tree HEAD^{tree} -p HEAD </dev/null`

  # now do the same "connected" test that receive-pack would do
  git rev-list --objects $sha1 --not --all

With a git.git with a ref for each revision, master needs (best of
five):

	real	0m2.210s
	user	0m2.188s
	sys	0m0.016s

And with this patch:

	real	0m0.480s
	user	0m0.456s
	sys	0m0.020s
Signed-off-by: NRene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Previously it was not possible to iterate revisions twice using the
revision walking api. We add a reset_revision_walk() which clears the
used flags. This allows us to do multiple sequencial revision walks.

We add the appropriate calls to the existing submodule machinery doing
revision walks. This is done to avoid surprises if future code wants to
call these functions more than once during the processes lifetime.
Signed-off-by: NHeiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

"git log -S<string>" is a useful way to find the last commit in the
codebase that touched the <string>. As it was designed to be used by a
porcelain script to dig the history starting from a block of text that
appear in the starting commit, it never had to look for anything but an
exact match.

When used by an end user who wants to look for the last commit that
removed a string (e.g. name of a variable) that he vaguely remembers,
however, it is useful to support case insensitive match.

When given the "--regexp-ignore-case" (or "-i") option, which originally
was designed to affect case sensitivity of the search done in the commit
log part, e.g. "log --grep", the matches made with -S/-G pickaxe search is
done case insensitively now.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Before the grep_source interface existed, grep_buffer was
used by two types of callers:

  1. Ones which pulled a file into a buffer, and then wanted
     to supply the file's name for the output (i.e.,
     git grep).

  2. Ones which really just wanted to grep a buffer (i.e.,
     git log --grep).

Callers in set (1) should now be using grep_source. Callers
in set (2) always pass NULL for the "name" parameter of
grep_buffer. We can therefore get rid of this now-useless
parameter.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In a topic branch workflow, you often want to find the latest commit that
merged a side branch that touched a particular area of the system, so that
a new topic branch to work on that area can be forked from that commit.
For example, I wanted to find an appropriate fork-point to queue Luke's
changes related to git-p4 in contrib/fast-import/.

"git log --first-parent" traverses the first-parent chain, and "-m --stat"
shows the list of paths touched by commits including merge commits.  We
could ask the question this way:

    # What is the latest commit that touched that path?
    $ git log --first-parent --oneline -m --stat master |
      sed -e '/^ contrib\/fast-import\/git-p4 /q' | tail

The above finds that 8cbfc118 (Merge branch 'pw/p4-view-updates',
2012-01-06) was such a commit.

But a more natural way to spell this question is this:

    $ git log --first-parent --oneline -m --stat -1 master -- \
      contrib/fast-import/git-p4

Unfortunately, this does not work. It finds ecb7cf98 (git-p4: rewrite view
handling, 2012-01-02). This commit is a part of the merged topic branch
and is _not_ on the first-parent path from the 'master':

    $ git show-branch 8cbfc118 ecb7cf98
    ! [8cbfc118] Merge branch 'pw/p4-view-updates'
     ! [ecb7cf98] git-p4: rewrite view handling
    --
    -  [8cbfc118] Merge branch 'pw/p4-view-updates'
    +  [8cbfc118^2] git-p4: view spec documentation
    ++ [ecb7cf98] git-p4: rewrite view handling

The problem is caused by the merge simplification logic when it inspects
the merge commit 8cbfc118. In this case, the history leading to the tip of
'master' did not touch git-p4 since 'pw/p4-view-updates' topic forked, and
the result of the merge is simply a copy from the tip of the topic branch
in the view limited by the given pathspec.  The merge simplification logic
discards the history on the mainline side of the merge, and pretends as if
the sole parent of the merge is its second parent, i.e. the tip of the
topic. While this simplification is correct in the general case, it is at
least surprising if not outright wrong when the user explicitly asked to
show the first-parent history.

Here is an attempt to fix this issue, by not allowing us to compare the
merge result with anything but the first parent when --first-parent is in
effect, to avoid the history traversal veering off to the side branch.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Recursion in a DAG is generally a bad idea because it could be very
deep. Be defensive and avoid recursion in mark_parents_uninteresting()
and clear_commit_marks().

mark_parents_uninteresting() learns a trick from clear_commit_marks()
to avoid malloc() in (dominant) single-parent case.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This teaches the "log" family of commands to pass the GPG signature in the
commit objects to "gpg --verify" via the verify_signed_buffer() interface
used to verify signed tag objects. E.g.

    $ git show --show-signature -s HEAD

shows GPG output in the header part of the output.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The new flag leak_pending in struct rev_info can be used to prevent
prepare_revision_walk from freeing the list of pending objects.  It
will still forget about them, so it really is leaked.  This behaviour
may look weird at first, but it can be useful if the pointer to the
list is saved before calling prepare_revision_walk.
Signed-off-by: NRene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This function is a combination of the static get_reference and
add_pending_object.  It can be used to easily queue objects by hash.
Signed-off-by: NRene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

HEAD and MERGE_HEAD (among other branch tips) should never hold a
tag. That can only be caused by broken tools and is cumbersome to fix
by an end user with:

  $ git update-ref HEAD $(git rev-parse HEAD^{commit})

which may look like a magic to a new person.

Be easy, warn users (so broken tools can be fixed if they bother to
report) and move on.

Be robust, if the given SHA-1 cannot be resolved to a commit object,
die (therefore return value is always valid).
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Often we want to verify everything reachable from a given set of commits
are present in our repository and connected without a gap to the tips of
our refs. We used to do this for this purpose:

    $ rev-list --objects $commits_to_be_tested --not --all

Even though this is good enough for catching missing commits and trees,
we show the object name but do not verify their existence, let alone their
well-formedness, for the blob objects at the leaf level.

Add a new "--verify-object" option so that we can catch missing and broken
blobs as well.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If the commit specified as the bottom of the commit range has a direct
parent that has another child commit that contributed to the resulting
history, "rev-list --ancestry-path" was confused and listed that side
history as well, due to the command line parser subtlety corrected by the
previous commit.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Given a complex set of revision specifiers on the command line, it is too
late to look at the flags of the objects in the initial traversal list at
the beginning of limit_list() in order to determine what the objects the
end-user explicitly listed on the command line were. The process to move
objects from the pending array to the traversal list may have marked
objects that are not mentioned as UNINTERESTING, when handle_commit()
marked the parents of UNINTERESTING commits mentioned on the command line
by calling mark_parents_uninteresting().

This made "rev-list --ancestry-path ^A ..." to mistakenly list commits
that are descendants of A's parents but that are not descendants of A
itself, as ^A from the command line causes A and its parents marked as
UNINTERESTING before coming to limit_list(), and we try to enumerate the
commits that are descendants of these commits that are UNINTERESTING
before we start walking the history.

It actually is too late even if we inspected the pending object array
before calling prepare_revision_walk(), as some of the same objects might
have been mentioned twice, once as positive and another time as negative.
The "rev-list --some-option A --not --all" command may want to notice,
even if the resulting set is empty, that the user showed some interest in
"A" and do something special about it.

Prepare a separate array to keep track of what syntactic element was used
to cause each object to appear in the pending array from the command line,
and populate it as setup_revisions() parses the command line.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Allocating and then immediately freeing temporary memory a million times
when listing a million objects is distasteful.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There are two copies of traverse_commit_list callback that show the object
name followed by pathname the object was found, to produce output similar
to "rev-list --objects".

Unify them.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Instead of barfing, simply ignore bad object names seen in the
input. This is useful when reading from "git notes list" output
that may refer to objects that have already been garbage collected.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add log.abbrevCommit config variable as a convenience for users who
often use --abbrev-commit with git log and friends. Allow the option
to be overridden with --no-abbrev-commit. Per 635530a2 and 4f62c2bc,
the config variable is ignored when log is given "--pretty=raw".

(Also, a drive-by spelling correction in git log's short help.)
Signed-off-by: NJay Soffian <jaysoffian@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If we later add a command in the log family that by default limit
its operation to the current subdirectory, we would need to resurrect
the "a lone ':' on the command line means no pathspec whatsoever".

Now the codepath was cleaned up, we can do so in one place.  Leave a
note to mark where it is for later generations.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When the command line has "--" disambiguator, we take the remainder of
argv[] as "prune_data", but when --stdin is given at the same time,
we need to append to the existing prune_data and end up attempting to
realloc(3) it.  That would not work.

Fix it by consistently using append_prune_data() throughout the input
processing.  Also avoid counting the number of existing paths in the
function over and over again.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

As v1.6.0-rc2~42 (2008-07-31) explains, even pseudo-options like --not
and --glob that need to be parsed in order with revisions should be
marked handled by handle_revision_opt to avoid an error when
parse_revision_opt callers like "git shortlog" encounter them.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

As v1.6.0-rc2~42 (Allow "non-option" revision options in
parse_option-enabled commands, 2008-07-31) explains, options handled
by setup_revisions fall into two categories:

 1. global options like --topo-order handled by parse_revision_opt,
    which can take detached arguments and can be parsed in advance;

 2. pseudo-options that must be parsed in order with their revision
    counterparts, like --not and --all.

The global options are taken care of by handle_revision_opt; the
pseudo-options are currently in a deeply indented portion of
setup_revisions.  Give them their own function for easier reading.

The only goal is to make setup_revisions easier to read straight
through.  No functional change intended.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

With most command line options, later instances of an option
override earlier ones. With cumulative options like
"--notes", however, there is no way to say "forget the
--notes I gave you before".

Let's have --no-notes trigger this forgetting, so that:

  git log --notes=foo --no-notes --notes=bar

will show only the "bar" notes.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>