alloc_nr, ALLOC_GROW, and ALLOC_GROW_BY are commonly used macros for
dynamic array allocation. Moving these macros to git-compat-util.h with
the other alloc macros focuses alloc.[ch] to allocation for Git objects
and additionally allows us to remove inclusions to alloc.h from files
that solely used the above macros.
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This also made it clear that several .c files depended upon various
things that oidset included, but had omitted the direct #include for
those headers. Add those now.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This allows us to replace includes of cache.h with includes of the much
smaller alloc.h in many places. It does mean that we also need to add
includes of alloc.h in a number of C files.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
String-lists may be used with callbacks for clearing or iteration. These
callbacks need to conform to a particular interface, even though not
every callback needs all of its parameters. Mark the unused ones to make
-Wunused-parameter happy.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a missing reflog_walk_info_release() to "reflog-walk.c" and use it
in release_revisions().
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the repo_dwim_log() function initially added as dwim_log() in
eb3a48221f (log --reflog: use dwim_log, 2007-02-09) to accept a NULL
oid parameter. The refs_resolve_ref_unsafe() function it invokes
already deals with it, but it didn't.
This allows for a bit more clarity in a reflog-walk.c codepath added
in f2eba66d4d (Enable HEAD@{...} and make it independent from the
current branch, 2007-02-03). We'll shortly use this in
builtin/reflog.c as well.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add and apply a semantic patch for converting code that open-codes
CALLOC_ARRAY to use it instead. It shortens the code and infers the
element size automatically.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Many more strings are prepared for l10n.
* nd/i18n: (23 commits)
transport-helper.c: mark more strings for translation
transport.c: mark more strings for translation
sha1-file.c: mark more strings for translation
sequencer.c: mark more strings for translation
replace-object.c: mark more strings for translation
refspec.c: mark more strings for translation
refs.c: mark more strings for translation
pkt-line.c: mark more strings for translation
object.c: mark more strings for translation
exec-cmd.c: mark more strings for translation
environment.c: mark more strings for translation
dir.c: mark more strings for translation
convert.c: mark more strings for translation
connect.c: mark more strings for translation
config.c: mark more strings for translation
commit-graph.c: mark more strings for translation
builtin/replace.c: mark more strings for translation
builtin/pack-objects.c: mark more strings for translation
builtin/grep.c: mark strings for translation
builtin/config.c: mark more strings for translation
...
Many messages will be marked for translation in the following
commits. This commit updates some of them to be more consistent and
reduce diff noise in those commits. Changes are
- keep the first letter of die(), error() and warning() in lowercase
- no full stop in die(), error() or warning() if it's single sentence
messages
- indentation
- some messages are turned to BUG(), or prefixed with "BUG:" and will
not be marked for i18n
- some messages are improved to give more information
- some messages are broken down by sentence to be i18n friendly
(on the same token, combine multiple warning() into one big string)
- the trailing \n is converted to printf_ln if possible, or deleted
if not redundant
- errno_errno() is used instead of explicit strerror()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow the callers of parse_object
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This allows us to get rid of several write-only variables.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
* jk/reflog-walk-maint:
reflog-walk: include all fields when freeing complete_reflogs
reflog-walk: don't free reflogs added to cache
reflog-walk: duplicate strings in complete_reflogs list
reflog-walk: skip over double-null oid due to HEAD rename
When we encounter an error adding reflogs for a walk, we try
to free any logs we have read. But we didn't free all
fields, meaning that we could in theory leak all of the
"items" array (which would consitute the bulk of the
allocated memory).
This patch adds a helper which frees all of the entries and
uses it as appropriate.
As it turns out, the leak seems impossible to trigger with
the current code. Of the three error paths that free the
complete_reflogs struct, two only kick in when the items
array is empty, and the third was removed entirely in the
previous commit.
So this patch should be a noop in terms of behavior, but it
fixes a potential maintenance headache should anybody add a
new error path and copy the partial-free code. Which is
what happened in 5026b47175 (add_reflog_for_walk: avoid
memory leak, 2017-05-04), though its leaky call was the
third one that was recently removed.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The add_reflog_for_walk() function keeps a cache mapping
refnames to their reflog contents. We use a cached reflog
entry if available, and otherwise allocate and store a new
one.
Since 5026b47175 (add_reflog_for_walk: avoid memory leak,
2017-05-04), when we hit an error parsing a date-based
reflog spec, we free the reflog memory but leave the cache
entry pointing to the now-freed memory.
We can fix this by just leaving the memory intact once it
has made it into the cache. This may leave an unused entry
in the cache, but that's OK. And it means we also catch a
similar situation: we may not have allocated at all in this
invocation, but simply be pointing to a cached entry from a
previous invocation (which is relying on that entry being
present).
The new test in t1411 exercises this case and fails when run
with --valgrind or ASan.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As part of the add_reflog_to_walk() function, we keep a
string_list mapping refnames to their reflog contents. This
serves as a cache so that accessing the same reflog twice
requires only a single copy of the log in memory.
The string_list is initialized via xcalloc, meaning its
strdup_strings field is set to 0. But after inserting a
string into the list, we unconditionally call free() on the
string, leaving the list pointing to freed memory. If
another reflog is added (e.g., "git log -g HEAD HEAD"), then
the second one may have unpredictable results.
The extra free was added by 5026b47175 (add_reflog_for_walk:
avoid memory leak, 2017-05-04). Though if you look
carefully, you can see that the code was buggy even before
then. If we tried to read the reflogs by time but came up
with no entries, we exited with an error, freeing the string
in that code path. So the bug was harder to trigger, but
still there.
We can fix it by just asking the string list to make a copy
of the string. Technically we could fix the problem by not
calling free() on our string (and just handing over
ownership to the string list), but there are enough
conditionals that it's quite hard to figure out which code
paths need the free and which do not. Simpler is better
here.
The new test reliably shows the problem when run with
--valgrind or ASAN.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 39ee4c6c2f (branch: record creation of renamed branch
in HEAD's log, 2017-02-20), a rename on the currently
checked out branch will create two entries in the HEAD
reflog: one where the branch goes away (switching to the
null oid), and one where it comes back (switching away from
the null oid).
This confuses the reflog-walk code. When walking backwards,
it first sees the null oid in the "old" field of the second
entry. Thanks to the "root commit" logic added by 71abeb753f
(reflog: continue walking the reflog past root commits,
2016-06-03), we keep looking for the next entry by scanning
the "new" field from the previous entry. But that field is
also null! We need to go just a tiny bit further, and look
at its "old" field. But with the current code, we decide the
reflog has nothing else to show and just give up. To the
user this looks like the reflog was truncated by the rename
operation, when in fact those entries are still there.
This patch does the absolute minimal fix, which is to look
back that one extra level and keep traversing.
The resulting behavior may not be the _best_ thing to do in
the long run (for example, we show both reflog entries each
with the same commit id), but it's a simple way to fix the
problem without risking further regressions.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Conversion from uchar[20] to struct object_id continues.
* bc/object-id: (53 commits)
object: convert parse_object* to take struct object_id
tree: convert parse_tree_indirect to struct object_id
sequencer: convert do_recursive_merge to struct object_id
diff-lib: convert do_diff_cache to struct object_id
builtin/ls-tree: convert to struct object_id
merge: convert checkout_fast_forward to struct object_id
sequencer: convert fast_forward_to to struct object_id
builtin/ls-files: convert overlay_tree_on_cache to object_id
builtin/read-tree: convert to struct object_id
sha1_name: convert internals of peel_onion to object_id
upload-pack: convert remaining parse_object callers to object_id
revision: convert remaining parse_object callers to object_id
revision: rename add_pending_sha1 to add_pending_oid
http-push: convert process_ls_object and descendants to object_id
refs/files-backend: convert many internals to struct object_id
refs: convert struct ref_update to use struct object_id
ref-filter: convert some static functions to struct object_id
Convert struct ref_array_item to struct object_id
Convert the verify_pack callback to struct object_id
Convert lookup_tag to struct object_id
...
We free()d the `log` buffer when dwim_log() returned 1, but not when it
returned a larger value (which meant that it still allocated the buffer
but we simply ignored it).
While in the vicinity, make sure that the `reflogs` structure as well as
the `branch` variable are released properly, too.
Identified by Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The semantic patch for standard object_id transforms found two
outstanding places where we could make a transformation automatically.
Apply these changes.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git's source code assumes that unsigned long is at least as precise as
time_t. Which is incorrect, and causes a lot of problems, in particular
where unsigned long is only 32-bit (notably on Windows, even in 64-bit
versions).
So let's just use a more appropriate data type instead. In preparation
for this, we introduce the new `timestamp_t` data type.
By necessity, this is a very, very large patch, as it has to replace all
timestamps' data type in one go.
As we will use a data type that is not necessarily identical to `time_t`,
we need to be very careful to use `time_t` whenever we interact with the
system functions, and `timestamp_t` everywhere else.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make each_reflog_ent_fn take two struct object_id pointers instead of
two pointers to unsigned char. Convert the various callbacks to use
struct object_id as well. Also, rename fsck_handle_reflog_sha1 to
fsck_handle_reflog_oid.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a few leaf functions in various files that call
resolve_refdup. Convert these functions to use struct object_id
internally to prepare for transitioning resolve_refdup itself.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If a repository contains more than one root commit, then its HEAD
reflog may contain multiple "creation events", i.e. entries whose
"from" value is the null sha1. Listing such a reflog currently stops
prematurely at the first such entry, even when the reflog still
contains older entries. This can scare users into thinking that their
reflog got truncated after 'git checkout --orphan'.
Continue walking the reflog past such creation events based on the
preceeding reflog entry's "new" value.
The test 'symbolic-ref writes reflog entry' in t1401-symbolic-ref
implicitly relies on the current behavior of the reflog walker to stop
at a root commit and thus to list only the reflog entries that are
relevant for that test. Adjust the test to explicitly specify the
number of relevant reflog entries to be listed.
Reported-by: Patrik Gustafsson <pvn@textalk.se>
Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git reflog" incorrectly assumed that all objects that used to be
at the tip of a ref must be commits, which caused it to segfault.
* dk/reflog-walk-with-non-commit:
reflog-walk: don't segfault on non-commit sha1's in the reflog
git reflog (ab)uses the log machinery to display its list of log
entries. To do so it must fake commit parent information for the log
walker.
For refs in refs/heads this is no problem, as they should only ever
point to commits. Tags and other refs however can point to anything,
thus their reflog may contain non-commit objects.
To avoid segfaulting, we check whether reflog entries are commits before
feeding them to the log walker and skip any non-commits. This means that
git reflog output will be incomplete for such refs, but that's one step
up from segfaulting. A more complete solution would be to decouple git
reflog from the log walker machinery.
Signed-off-by: Dennis Kaarsemaker <dennis@kaarsemaker.net>
Helped-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's a common pattern to do:
foo = xmalloc(strlen(one) + strlen(two) + 1 + 1);
sprintf(foo, "%s %s", one, two);
(or possibly some variant with strcpy()s or a more
complicated length computation). We can switch these to use
xstrfmt, which is shorter, involves less error-prone manual
computation, and removes many sprintf and strcpy calls which
make it harder to audit the code for real buffer overflows.
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>
resolve_ref_unsafe takes a boolean argument for reading (a nonexistent ref
resolves successfully for writing but not for reading). Change this to be
a flags field instead, and pass the new constant RESOLVE_REF_READING when
we want this behaviour.
While at it, swap two of the arguments in the function to put output
arguments at the end. As a nice side effect, this ensures that we can
catch callers that were unaware of the new API so they can be audited.
Give the wrapper functions resolve_refdup and read_ref_full the same
treatment for consistency.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
xcalloc() takes two arguments: the number of elements and their size.
reflog-walk.c includes several calls to xcalloc() that pass the arguments
in reverse order.
Rearrange them so they are in the correct order.
Signed-off-by: Brian Gesiak <modocache@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We invented hashcpy() to keep the abstraction of "object name"
behind it. Use it instead of calling memcpy() with hard-coded
20-byte length when moving object names between pieces of memory.
Leave ppc/sha1.c as-is, because the function is about the SHA-1 hash
algorithm whose output is and will always be 20 bytes.
Helped-by: Michael Haggerty <mhagger@alum.mit.edu>
Helped-by: Duy Nguyen <pclouds@gmail.com>
Signed-off-by: Sun He <sunheehnus@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use ALLOC_GROW() instead of open-coding it in add_commit_info() and
read_one_reflog().
Signed-off-by: Dmitry S. Dolzhenko <dmitrys.dolzhenko@yandex.ru>
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 we are showing reflog selectors during a walk, we infer
from context whether the user wanted to see the index in
each selector, or the reflog date. The current rules are:
1. if the user asked for an explicit date format in the
output, show the date
2. if the user asked for ref@{now}, show the date
3. if neither is true, show the index
However, if we see "ref@{0}", that should be a strong clue
that the user wants to see the counted version. In fact, it
should be much stronger than the date format in (1). The
user may have been setting the date format to use in another
part of the output (e.g., in --format="%gd (%ad)", they may
have wanted to influence the author date).
This patch flips the rules to:
1. if the user asked for ref@{0}, always show the index
2. if the user asked for ref@{now}, always show the date
3. otherwise, we have just "ref"; show them counted by
default, but respect the presence of "--date" as a clue
that the user wanted them date-based
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we prepare to walk a reflog, we parse the specification
and pull some information from it, such as which reflog to
look in (e.g., HEAD), and where to start (e.g., HEAD@{10} or
HEAD@{yesterday}). The resulting struct has a "recno" field
to show where in the reflog we are starting. It also has a
"flag" field; if true, it means the recno field came from
parsing a date like HEAD@{yesterday}.
There are two problems with this:
1. "flag" is an absolutely terrible name, as it conveys
nothing about the meaning
2. you can tell "HEAD" from "HEAD@{yesterday}", but you
can't differentiate "HEAD" from "HEAD{0}"
This patch converts the flag into a tri-state (and gives it
a better name!).
Signed-off-by: Jeff King <peff@peff.net>
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>
resolve_ref() may return a pointer to a static buffer. Callers that
use this value longer than a couple of statements should copy the
value to avoid some hidden resolve_ref() call that may change the
static buffer's value.
The bug found by Tony Wang <wwwjfy@gmail.com> in builtin/merge.c
demonstrates this. The first call is in cmd_merge()
branch = resolve_ref("HEAD", head_sha1, 0, &flag);
Then deep in lookup_commit_or_die() a few lines after, resolve_ref()
may be called again and destroy "branch".
lookup_commit_or_die
lookup_commit_reference
lookup_commit_reference_gently
parse_object
lookup_replace_object
do_lookup_replace_object
prepare_replace_object
for_each_replace_ref
do_for_each_ref
get_loose_refs
get_ref_dir
get_ref_dir
resolve_ref
All call sites are checked and made sure that xstrdup() is called if
the value should be saved.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The reflog-walking mechanism is based on the regular
revision traversal. We just rewrite the parents of each
commit in fake_reflog_parent to point to the commit in the
next reflog entry instead of the real parents.
However, the regular revision traversal tries not to show
the same commit twice, and so sets the SHOWN flag on each
commit it shows. In a reflog, however, we may want to see
the same commit more than once if it appears in the reflog
multiple times (which easily happens, for example, if you do
a reset to a prior state).
The fake_reflog_parent function takes care of this by
clearing flags, including SHOWN. Unfortunately, it does so
at the very end of the function, and it is possible to
return early from the function if there is no fake parent to
set up (e.g., because we are at the very first reflog entry
on the branch). In such a case the flag is not cleared, and
the entry is skipped by the revision traversal machinery as
already shown.
You can see this by walking the log of a ref which is set to
its very first commit more than once (the test below shows
such a situation). In this case the reflog walk will fail to
show the entry for the initial creation of the ref.
We don't want to simply move the flag-clearing to the top of
the function; we want to make sure flags set during the
fake-parent installation are also cleared. Instead, let's
hoist the flag-clearing out of the fake_reflog_parent
function entirely. It's not really about fake parents
anyway, and the only caller is the get_revision machinery.
Reported-by: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
