Stop emitting an error message when deleting a packed reference if we
find another dangling packed reference that is overridden by a loose
reference.  See the previous commit for a longer explanation of the
issue.

We have to be careful to make sure that the invalid packed reference
really *is* overridden by a loose reference; otherwise what we have
found is repository corruption, which we *should* report.

Please note that this approach is vulnerable to a race condition
similar to the race conditions already known to affect packed
references [1]:

* Process 1 tries to peel packed reference X as part of deleting
  another packed reference.  It discovers that X does not refer to a
  valid object (because the object that it referred to has been
  garbage collected).

* Process 2 tries to delete reference X.  It starts by deleting the
  loose reference X.

* Process 1 checks whether there is a loose reference X.  There is not
  (it has just been deleted by process 2), so process 1 reports a
  spurious error "X does not point to a valid object!"

The worst case seems relatively harmless, and the fix is identical to
the fix that will be needed for the other race conditions (namely
holding a lock on the packed-refs file during *all* reference
deletions), so we leave the cleaning up of all of them as a future
project.

[1] http://thread.gmane.org/gmane.comp.version-control.git/211956Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

A packed reference can be overridden by a loose reference, in which
case the packed reference is obsolete and is never used.  The object
pointed to by such a reference can be garbage collected.  Since
d66da478, this could lead to the emission of a spurious error
message:

    error: refs/heads/master does not point to a valid object!

The error is generated by repack_without_ref() if there is an obsolete
dangling packed reference in packed-refs when the packed-refs file has
to be rewritten due to the deletion of another packed reference.  Add
a failing test demonstrating this problem and some passing tests of
related scenarios.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Establish an internal API for iterating over references, which gives
the callback functions direct access to the ref_entry structure
describing the reference.  (Do not change the iteration API that is
exposed outside of the module.)

Define a new internal callback signature

   int each_ref_entry_fn(struct ref_entry *entry, void *cb_data)

Change do_for_each_ref_in_dir() and do_for_each_ref_in_dirs() to
accept each_ref_entry_fn callbacks, and rename them to
do_for_each_entry_in_dir() and do_for_each_entry_in_dirs(),
respectively.  Adapt their callers accordingly.

Add a new function do_for_each_entry() analogous to do_for_each_ref()
but using the new callback style.

Change do_one_ref() into an each_ref_entry_fn that does some
bookkeeping and then calls a wrapped each_ref_fn.

Reimplement do_for_each_ref() in terms of do_for_each_entry(), using
do_one_ref() as an adapter.

Please note that the responsibility for setting current_ref remains in
do_one_ref(), which means that current_ref is *not* set when iterating
over references via the new internal API.  This is not a disadvantage,
because current_ref is not needed by callers of the internal API (they
receive a pointer to the current ref_entry anyway).  But more
importantly, this change prevents peel_ref() from returning invalid
results in the following scenario:

When iterating via the external API, the iteration always includes
both packed and loose references, and in particular never presents a
packed ref if there is a loose ref with the same name.  The internal
API, on the other hand, gives the option to iterate over only the
packed references.  During such an iteration, there is no check
whether the packed ref might be hidden by a loose ref of the same
name.  But until now the packed ref was recorded in current_ref during
the iteration.  So if peel_ref() were called with the reference name
corresponding to current ref, it would return the peeled version of
the packed ref even though there might be a loose ref that peels to a
different value.  This scenario doesn't currently occur in the code,
but fix it to prevent things from breaking in a very confusing way in
the future.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Peel the entry, and as a side effect store the peeled value in the
entry.  Use this function from two places in peel_ref(); a third
caller will be added soon.

Please note that this change can lead to ref_entries for unpacked refs
being peeled.  This has no practical benefit but is harmless.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The old version was inconsistent: when a reference was
REF_KNOWS_PEELED but with a null peeled value, it returned non-zero
for the current reference but zero for other references.  Change the
behavior for non-current references to match that of current_ref,
which is what callers expect.  Document the behavior.

Current callers only call peel_ref() from within a for_each_ref-style
iteration and only for the current ref; therefore, the buggy code path
was never reached.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Instead of just returning a success/failure bit, return an enumeration
value that explains the reason for any failure.  This will come in
handy shortly.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It is a nice, logical unit of work, and putting it in a function
removes the need to use a goto in peel_ref().  Soon it will also have
other uses.

The algorithm is unchanged.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It is a nice unit of work and soon will be needed from multiple
locations.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Instead of copying the reference's SHA1 into a caller-supplied
variable, just return the ref_entry itself (or NULL if there is no
such entry).  This change will allow the function to be used from
elsewhere.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There is no way to drop out of the while loop.  This code has been
dead since 432ad41e.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Document the bits that can appear in the "flags" parameter passed to
an each_ref_function and/or in the ref_entry::flag field.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Earlier we added support for --expire=all (or --expire=now) that
considers all crufts, regardless of their age, as eligible for
garbage collection by turning command argument parsers that use
approxidate() to use parse_expiry_date(), but "git prune" used a
built-in parse-options facility OPT_DATE() and did not benefit from
the new function.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Document that the "no-" prefix can also be used for non-boolean
options.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Document the new values that can be used for expiry values where their
use makes sense:

* git reflog expire --expire=[all|never]
* git reflog expire --expire-unreachable=[all|never]
* git gc --prune=all

Other combinations aren't useful and therefore no documentation is
added (even though they are allowed):

* git gc --prune=never

  is redundant with "git gc --no-prune"

* git prune --expire=all

  is equivalent to providing no --expire option

* git prune --expire=never

  is a NOP
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

"git reflog --expire=all" tries to expire reflog entries up to the
current second, because the approxidate() parser gives the current
timestamp for anything it does not understand (and it does not know
what time "all" means).  When the user tells us to expire "all" (or
set the expiration time to "now"), the user wants to remove all the
reflog entries (no reflog entry should record future time).

Just set it to ULONG_MAX and to let everything that is older that
timestamp expire.

While at it, allow "now" to be treated the same way for callers that
parse expiry date timestamp with this function.  Also use an error
reporting version of approxidate() to report misspelled date.  When
the user says e.g. "--expire=mnoday" to delete entries two days or
older on Wednesday, we wouldn't want the "unknown, default to now"
logic to kick in.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The --signed-tags argument is plural, while error messages referred
to --signed-tag (singular).  Tweak error messages to correspond to the
argument.
Signed-off-by: NPaul Price <price@astro.princeton.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

eb32d236 introduced the OBJ_OFS_DELTA object that uses a relative offset to
identify the base object instead of the 20-byte SHA1 reference. The pack file
documentation only mentions the SHA1 based reference in its description of the
deltified object entry.

Update the pack format documentation to clarify that the deltified object
representation refers to its base using either a relative negative offset or
the absolute SHA1 identifier.
Signed-off-by: NStefan Saasen <ssaasen@atlassian.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

A pattern "dir" (without trailing slash) in the attributes file
stopped matching a directory "dir" by mistake with an earlier change
that wanted to allow pattern "dir/" to also match.

* jc/directory-attrs-regression-fix:
  t: check that a pattern without trailing slash matches a directory
  dir.c::match_pathname(): pay attention to the length of string parameters
  dir.c::match_pathname(): adjust patternlen when shifting pattern
  dir.c::match_basename(): pay attention to the length of string parameters
  attr.c::path_matches(): special case paths that end with a slash
  attr.c::path_matches(): the basename is part of the pathname

Using grep "devel\s\+3:" to find at least one whitspace is not
portable on all grep versions; not all grep versions understand "\s"
as a "whitespace".

Use a literal TAB followed by SPACE.

The + as a qualifier for "one or more" is not a basic regular
expression; use egrep instead of grep.
Signed-off-by: NTorsten Bögershausen <tboegi@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

* kb/name-hash:
  name-hash.c: fix endless loop with core.ignorecase=true

* kk/revwalk-slop-too-many-commit-within-a-second:
  Fix revision walk for commits with the same dates

* jk/checkout-attribute-lookup:
  t2003: work around path mangling issue on Windows
  entry: fix filter lookup
  t2003: modernize style

* jk/fully-peeled-packed-ref:
  pack-refs: add fully-peeled trait
  pack-refs: write peeled entry for non-tags
  use parse_object_or_die instead of die("bad object")
  avoid segfaults on parse_object failure

* ap/maint-diff-rename-avoid-overlap:
  tests: make sure rename pretty print works
  diff: prevent pprint_rename from underrunning input
  diff: Fix rename pretty-print when suffix and prefix overlap

* yd/doc-merge-annotated-tag:
  Documentation: merging a tag is a special case

* ap/maint-update-index-h-is-for-help:
  update-index: allow "-h" to also display options

* jc/perl-cat-blob:
  Git.pm: fix cat_blob crashes on large files

* ob/imap-send-ssl-verify:
  imap-send: support Server Name Indication (RFC4366)

* nd/index-pack-l10n-buf-overflow:
  index-pack: fix buffer overflow caused by translations

The <commit>|<object> argument is actually not explained anywhere
(except implicitly in the description of an unannotated tag).  Write a
little explanation, in particular to cover the default.
Signed-off-by: NThomas Rast <trast@inf.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Prior to v1.8.1.1, with:

  git init
  echo content >foo &&
  mkdir subdir &&
  echo content >subdir/bar &&
  echo "subdir export-ignore" >.gitattributes
  git add . &&
  git commit -m one &&
  git archive HEAD | tar tf -

the resulting archive would contain only "foo" and ".gitattributes",
not subdir.  This was broken with a recent change that intended to
allow "subdir/ export-ignore" to also exclude the directory, but
instead ended up _requiring_ the trailing slash by mistake.

A pattern "subdir" should match any path "subdir", whether it is a
directory or a non-directory.  A pattern "subdir/" insists that a
path "subdir" must be a directory for it to match.

This patch adds test not just for this simple case, but also for
deeper cross-directory cases, as well as cases with wildcards.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This function takes two counted strings: a <pattern, patternlen> pair
and a <pathname, pathlen> pair. But we end up feeding the result to
fnmatch, which expects NUL-terminated strings.

We can fix this by calling the fnmatch_icase_mem function, which
handles re-allocating into a NUL-terminated string if necessary.

While we're at it, we can avoid even calling fnmatch in some cases. In
addition to patternlen, we get "prefix", the size of the pattern that
contains no wildcard characters. We do a straight match of the prefix
part first, and then use fnmatch to cover the rest. But if there are
no wildcards in the pattern at all, we do not even need to call
fnmatch; we would simply be comparing two empty strings.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>