vcs-svn: rename check_overflow and its arguments for clarity

The canonical interpretation of a range a,b is as an interval [a,b),
not [a,a+b), so this function taking argument names a and b feels
unnatural.  Use more explicit names "offset" and "len" to make the
arguments' type and function clearer.

While at it, rename the function to convey that we are making sure
the sum of this offset and length do not overflow an off_t, not a
size_t.

[jn: split out from a patch from Ramsay Jones, then improved with
 advice from Thomas Rast, Dmitry Ivankov, and David Barr]

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Improved-by: Dmitry Ivankov <divanorama@gmail.com>
vcs-svn: allow import of > 4GiB files

There is no reason in principle that an svn-format dump would not
be able to represent a file whose length does not fit in a 32-bit
integer.  Use off_t consistently (instead of uint32_t) to represent
file lengths so we can handle that.

Most of our code is already ready to do that without this patch and
already passes values of type off_t around.  The type mismatch due to
stragglers was noticed with gcc -Wtype-limits.

Inspired-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
vcs-svn: suppress -Wtype-limits warning

On 32-bit architectures with 64-bit file offsets, gcc 4.3 and earlier
produce the following warning:

	    CC vcs-svn/sliding_window.o
	vcs-svn/sliding_window.c: In function `check_overflow':
	vcs-svn/sliding_window.c:36: warning: comparison is always false \
	    due to limited range of data type

The warning appears even when gcc is run without any warning flags
(PR12963).  In later versions it can be reproduced with -Wtype-limits,
which is implied by -Wextra.

On 64-bit architectures it really is possible for a size_t not to be
representable as an off_t so the check being warned about is not
actually redundant.  But even false positives are distracting.  Avoid
the warning by making the "len" argument to check_overflow a
uintmax_t; no functional change intended.

Reported-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Update Swedish translation (1066t0f0u)

Signed-off-by: Peter Krefting <peter@softwolves.pp.se>
blame: compute abbreviation width that ensures uniqueness

Julia Lawall noticed that in linux-next repository the commit object
60d5c9f5 (shown with the default abbreviation width baked into "git
blame") in output from

  $ git blame -L 3675,3675 60d5c9f5b -- \
      drivers/staging/brcm80211/brcmfmac/wl_iw.c

is no longer unique in the repository, which results in "short SHA1
60d5c9f5 is ambiguous".

Compute the minimum abbreviation width that ensures uniqueness when
the user did not specify the --abbrev option to avoid this.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
sha1_name.c: hide get_sha1_with_context_1() ugliness

There is no outside caller that cares about the "only-to-die" ugliness.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'maint' of git://github.com/git-l10n/git-po into maint

Update Swedish translation (1066t0f0u)
Sync with i18n-po updates in maint

# By Peter Krefting
# Via Junio C Hamano (1) and Peter Krefting (1)
* maint:
  Update Swedish translation (1066t0f0u)
l10n: Update git.pot (29 new messages)

Generate po/git.pot from v1.7.11.1-107-g72601, and there are 29 new l10n
messages.

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
l10n: Update translation for Vietnamese

 * Translated 29 news
 * Fix some minor errors in old translation

Signed-off-by: Tran Ngoc Quan <vnwildman@gmail.com>
sha1_name.c: get rid of get_sha1_with_mode_1()

The only external caller is setup.c that tries to give a nicer error
message when an object name is misspelt (e.g. "HEAD:cashe.h").
Retire it and give the caller a dedicated and more intuitive API
function maybe_die_on_misspelt_object_name().

Signed-off-by: Junio C Hamano <gitster@pobox.com>
sha1_name.c: get rid of get_sha1_with_mode()

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: Junio C Hamano <gitster@pobox.com>
sha1_name.c: clarify what "fake" is for in find_short_object_filename()

Signed-off-by: Junio C Hamano <gitster@pobox.com>
sha1_name.c: rename "now" to "current"

This variable points at the element we are currently looking at, and
does not have anything to do with the current time which the name
"now" implies.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
sha1_name.c: refactor find_short_packed_object()

Extract the logic to find object(s) that match a given prefix inside
a single pack into a separate helper function, and give it a bit more
comment.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
sha1_name.c: correct misnamed "canonical" and "res"

These are hexadecimal and binary representation of the short object
name given to the callchain as its input.  Rename them with _pfx
suffix to make it clear they are prefixes, and call them hex and bin
respectively.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
sha1_name.c: restructure disambiguation of short names

We try to find zero, one or more matches from loose objects and
packed objects independently and then decide if the given short
object name is unique across them.

Instead, introduce a "struct disambiguate_state" that keeps track of
what we have found so far, that can be one of:

 - We have seen one object that _could_ be what we are looking for;
 - We have also checked that object for additional constraints (if any),
   and found that the object satisfies it;
 - We have also checked that object for additional constraints (if any),
   and found that the object does not satisfy it; or
 - We have seen more than one objects that satisfy the constraints.

and pass it to the enumeration functions for loose and packed
objects.  The disambiguation state can optionally take a callback
function that takes a candidate object name and reports if the
object satisifies additional criteria (e.g. when the caller knows
that the short name must refer to a commit, this mechanism can be
used to check the type of the given object).

Compared to the earlier attempt, this round avoids the optional
check if there is only one candidate that matches the short name in
the first place.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
get_sha1(): fix error status regression

In finish_object_disambiguation(), if the candidate hasn't been
checked, there are two cases:

 - It is the first and only object that match the prefix; or
 - It replaced another object that matched the prefix but that
   object did not satisfy ds->fn() callback.

And the former case we set ds->candidate_ok to true without doing
anything else, while for the latter we check the candidate, which
may set ds->candidate_ok to false.

At this point in the code, ds->candidate_ok can be false only if
this last-round check found that the candidate does not pass the
check, because the state after update_candidates() returns cannot
satisfy

    !ds->ambiguous && ds->candidate_exists && ds->candidate_checked

and !ds->canidate_ok at the same time.

Hence, when we execute this "return", we know we have seen more than
one object that match the prefix (and none of them satisfied ds->fn),
meaning that we should say "the short name is ambiguous", not "there
is no object that matches the prefix".

Noticed by Jeff King.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
sha1_name.c: allow get_short_sha1() to take other flags

Instead of a separate "int quietly" argument, make it take "unsigned
flags" so that we can pass other options to it.

The bit assignment of this flag word is exposed in cache.h because
the mechanism will be exposed to callers of the higher layer in
later commits in this series.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
sha1_name.c: teach get_short_sha1() a commit-only option

When the caller knows that the parameter is meant to name a commit,
e.g. "56789a" in describe name "v1.2.3-4-g56789a", pass that as a
hint so that lower level can use it to disambiguate objects when
there is only one commit whose name begins with 56789a even if there
are objects of other types whose names share the same prefix.

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