When pack-objects is given --include-tag, it peels each tag
ref down to a non-tag object, and if that non-tag object is
going to be packed, we include the tag, too. But what
happens if we have a chain of tags (e.g., tag "A" points to
tag "B", which points to commit "C")?
We'll peel down to "C" and realize that we want to include
tag "A", but we do not ever consider tag "B", leading to a
broken pack (assuming "B" was not otherwise selected).
Instead, we have to walk the whole chain, adding any tags we
find to the pack.
Interestingly, it doesn't seem possible to trigger this
problem with "git fetch", but you can with "git clone
--single-branch". The reason is that we generate the correct
pack when the client explicitly asks for "A" (because we do
a real reachability analysis there), and "fetch" is more
willing to do so. There are basically two cases:
1. If "C" is already a ref tip, then the client can deduce
that it needs "A" itself (via find_non_local_tags), and
will ask for it explicitly rather than relying on the
include-tag capability. Everything works.
2. If "C" is not already a ref tip, then we hope for
include-tag to send us the correct tag. But it doesn't;
it generates a broken pack. However, the next step is
to do a follow-up run of find_non_local_tags(),
followed by fetch_refs() to backfill any tags we
learned about.
In the normal case, fetch_refs() calls quickfetch(),
which does a connectivity check and sees we have no
new objects to fetch. We just write the refs.
But for the broken-pack case, the connectivity check
fails, and quickfetch will follow-up with the remote,
asking explicitly for each of the ref tips. This picks
up the missing object in a new pack.
For a regular "git clone", we are similarly OK, because we
explicitly request all of the tag refs, and get a correct
pack. But with "--single-branch", we kick in tag
auto-following via "include-tag", but do _not_ do a
follow-up backfill. We just take whatever the server sent us
via include-tag and write out tag refs for any tag objects
we were sent. So prior to c6807a4 (clone: open a shortcut
for connectivity check, 2013-05-26), we actually claimed the
clone was a success, but the result was silently
corrupted! Since c6807a4, index-pack's connectivity
check catches this case, and we correctly complain.
The included test directly checks that pack-objects does not
generate a broken pack, but also confirms that "clone
--single-branch" does not hit the bug.
Note that tag chains introduce another interesting question:
if we are packing the tag "B" but not the commit "C", should
"A" be included?
Both before and after this patch, we do not include "A",
because the initial peel_ref() check only knows about the
bottom-most level, "C". To realize that "B" is involved at
all, we would have to switch to an incremental peel, in
which we examine each tagged object, asking if it is being
packed (and including the outer tag if so).
But that runs contrary to the optimizations in peel_ref(),
which avoid accessing the objects at all, in favor of using
the value we pull from packed-refs. It's OK to walk the
whole chain once we know we're going to include the tag (we
have to access it anyway, so the effort is proportional to
the pack we're generating). But for the initial selection,
we have to look at every ref. If we're only packing a few
objects, we'd still have to parse every single referenced
tag object just to confirm that it isn't part of a tag
chain.
This could be addressed if packed-refs stored the complete
tag chain for each peeled ref (in most cases, this would be
the same cost as now, as each "chain" is only a single
link). But given the size of that project, it's out of scope
for this fix (and probably nobody cares enough anyway, as
it's such an obscure situation). This commit limits itself
to just avoiding the creation of a broken pack.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Not-so-recent rewrite of "git am" that started making internal
calls into the commit machinery had an unintended regression, in
that no matter how many seconds it took to apply many patches, the
resulting committer timestamp for the resulting commits were all
the same.
* jk/reset-ident-time-per-commit:
am: reset cached ident date for each patch
"git commit --help" said "--no-verify" is only about skipping the
pre-commit hook, and failed to say that it also skipped the
commit-msg hook.
* os/no-verify-skips-commit-msg-too:
commit: describe that --no-verify skips the commit-msg hook in the help text
The use of strbuf in "git rm" to build filename to remove was a bit
suboptimal, which has been fixed.
* rs/rm-strbuf-optim:
rm: reuse strbuf for all remove_dir_recursively() calls
Users of the parse_options_concat() API function need to allocate
extra slots in advance and fill them with OPT_END() when they want
to decide the set of supported options dynamically, which makes the
code error-prone and hard to read. This has been corrected by tweaking
the API to allocate and return a new copy of "struct option" array.
* jk/parse-options-concat:
parse_options: allocate a new array when concatenating
"git pack-objects" and "git index-pack" mostly operate with off_t
when talking about the offset of objects in a packfile, but there
were a handful of places that used "unsigned long" to hold that
value, leading to an unintended truncation.
* nd/pack-ofs-4gb-limit:
fsck: use streaming interface for large blobs in pack
pack-objects: do not truncate result in-pack object size on 32-bit systems
index-pack: correct "offset" type in unpack_entry_data()
index-pack: report correct bad object offsets even if they are large
index-pack: correct "len" type in unpack_data()
sha1_file.c: use type off_t* for object_info->disk_sizep
pack-objects: pass length to check_pack_crc() without truncation
"git blame file" allowed the lineage of lines in the uncommitted,
unadded contents of "file" to be inspected, but it refused when
"file" did not appear in the current commit. When "file" was
created by renaming an existing file (but the change has not been
committed), this restriction was unnecessarily tight.
* mh/blame-worktree:
t/t8003-blame-corner-cases.sh: Use here documents
blame: allow to blame paths freshly added to the index
Call strbuf_addstr() for adding a simple string to a strbuf instead of
using the heavier strbuf_addf(). This is shorter and documents the
intent more clearly.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we compute the date to go in author/committer lines of
commits, or tagger lines of tags, we get the current date
once and then cache it for the rest of the program. This is
a good thing in some cases, like "git commit", because it
means we do not racily assign different times to the
author/committer fields of a single commit object.
But as more programs start to make many commits in a single
process (e.g., the recently builtin "git am"), it means that
you'll get long strings of commits with identical committer
timestamps (whereas before, we invoked "git commit" many
times and got true timestamps).
This patch addresses it by letting callers reset the cached
time, which means they'll get a fresh time on their next
call to git_committer_info() or git_author_info(). The first
caller to do so is "git am", which resets the time for each
patch it applies.
It would be nice if we could just do this automatically
before filling in the ident fields of commit and tag
objects. Unfortunately, it's hard to know where a particular
logical operation begins and ends.
For instance, if commit_tree_extended() were to call
reset_ident_date() before getting the committer/author
ident, that doesn't quite work; sometimes the author info is
passed in to us as a parameter, and it may or may not have
come from a previous call to ident_default_date(). So in
those cases, we lose the property that the committer and the
author timestamp always match.
You could similarly put a date-reset at the end of
commit_tree_extended(). That actually works in the current
code base, but it's fragile. It makes the assumption that
after commit_tree_extended() finishes, the caller has no
other operations that would logically want to fall into the
same timestamp.
So instead we provide the tool to easily do the reset, and
let the high-level callers use it to annotate their own
logical operations.
There's no automated test, because it would be inherently
racy (it depends on whether the program takes multiple
seconds to run). But you can see the effect with something
like:
# make a fake 100-patch series
top=$(git rev-parse HEAD)
bottom=$(git rev-list --first-parent -100 HEAD | tail -n 1)
git log --format=email --reverse --first-parent \
--binary -m -p $bottom..$top >patch
# now apply it; this presumably takes multiple seconds
git checkout --detach $bottom
git am <patch
# now count the number of distinct committer times;
# prior to this patch, there would only be one, but
# now we'd typically see several.
git log --format=%ct $bottom.. | sort -u
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Helped-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Replace uses of strbuf_addf() for adding strings with more lightweight
strbuf_addstr() calls.
In http-push.c it becomes easier to see what's going on without having
to verfiy that the definition of PROPFIND_ALL_REQUEST doesn't contain
any format specifiers.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git blame -M" missed a single line that was moved within the file.
* dk/blame-move-no-reason-for-1-line-context:
blame: require 0 context lines while finding moved lines with -M
One part of "git am" had an oddball helper function that called
stuff from outside "his" as opposed to calling what we have "ours",
which was not gender-neutral and also inconsistent with the rest of
the system where outside stuff is usuall called "theirs" in
contrast to "ours".
* js/am-call-theirs-theirs-in-fallback-3way:
am: counteract gender bias
"gc.autoPackLimit" when set to 1 should not trigger a repacking
when there is only one pack, but the code counted poorly and did
so.
* ew/gc-auto-pack-limit-fix:
gc: fix off-by-one error with gc.autoPackLimit
Git does not know what the contents in the index should be for a
path added with "git add -N" yet, so "git grep --cached" should not
show hits (or show lack of hits, with -L) in such a path, but that
logic does not apply to "git grep", i.e. searching in the working
tree files. But we did so by mistake, which has been corrected.
* nd/ita-cleanup:
grep: fix grepping for "intent to add" files
t7810-grep.sh: fix a whitespace inconsistency
t7810-grep.sh: fix duplicated test name
A helper function that takes the contents of a commit object and
finds its subject line did not ignore leading blank lines, as is
commonly done by other codepaths. Make it ignore leading blank
lines to match.
* js/find-commit-subject-ignore-leading-blanks:
reset --hard: skip blank lines when reporting the commit subject
sequencer: use skip_blank_lines() to find the commit subject
commit -C: skip blank lines at the beginning of the message
commit.c: make find_commit_subject() more robust
pretty: make the skip_blank_lines() function public
This brings the short help in line with the documentation.
Signed-off-by: Orgad Shaneh <orgads@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When blaming files, changes in the work tree are taken into account
and displayed as being "Not Committed Yet".
However, when blaming a file that is not known to the current HEAD,
git blame fails with `no such path 'foo' in HEAD`, even when the file
was git add'ed.
Allowing such a blame is useful when the new file added to the index
(not yet committed) was created by renaming an existing file. It
also is useful when the new file was created from pieces already in
HEAD, moved or copied from other files and blaming with copy
detection (i.e. "-C").
Signed-off-by: Mike Hommey <mh@glandium.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For blobs, we want to make sure the on-disk data is not corrupted
(i.e. can be inflated and produce the expected SHA-1). Blob content is
opaque, there's nothing else inside to check for.
For really large blobs, we may want to avoid unpacking the entire blob
in memory, just to check whether it produces the same SHA-1. On 32-bit
systems, we may not have enough virtual address space for such memory
allocation. And even on 64-bit where it's not a problem, allocating a
lot more memory could result in kicking other parts of systems to swap
file, generating lots of I/O and slowing everything down.
For this particular operation, not unpacking the blob and letting
check_sha1_signature, which supports streaming interface, do the job
is sufficient. check_sha1_signature() is not shown in the diff,
unfortunately. But if will be called when "data_valid && !data" is
false.
We will call the callback function "fn" with NULL as "data". The only
callback of this function is fsck_obj_buffer(), which does not touch
"data" at all if it's a blob.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A typical diff will not show what's going on and you need to see full
functions. The core code is like this, at the end of of write_one()
e->idx.offset = *offset;
size = write_object(f, e, *offset);
if (!size) {
e->idx.offset = recursing;
return WRITE_ONE_BREAK;
}
written_list[nr_written++] = &e->idx;
/* make sure off_t is sufficiently large not to wrap */
if (signed_add_overflows(*offset, size))
die("pack too large for current definition of off_t");
*offset += size;
Here we can see that the in-pack object size is returned by
write_object (or indirectly by write_reuse_object). And it's used to
calculate object offsets, which end up in the pack index file,
generated at the end.
If "size" overflows (on 32-bit sytems, unsigned long is 32-bit while
off_t can be 64-bit), we got wrong offsets and produce incorrect .idx
file, which may make it look like the .pack file is corrupted.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
unpack_entry_data() receives an off_t value from unpack_raw_entry(),
which could be larger than unsigned long on 32-bit systems with large
file support. Correct the type so truncation does not happen. This
only affects bad object reporting though.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the right type for offsets in this case, off_t, which makes a
difference on 32-bit systems with large file support, and change
formatting code accordingly.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On 32-bit systems with large file support, one entry could be larger
than 4GB and overflow "len". Correct it so we can unpack a full entry.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This field, filled by sha1_object_info() contains the on-disk size of
an object, which could go over 4GB limit of unsigned long on 32-bit
systems. Use off_t for it instead and update all callers.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Don't throw the memory allocated for remove_dir_recursively() away after
a single call, use it for the other entries as well instead.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On 32 bit systems with large file support, unsigned long is 32-bit
while the two offsets in the subtraction expression (pack-objects has
the exact same expression as in sha1_file.c but not shown in diff) are
in 64-bit. If an in-pack object is larger than 2^32 len/datalen is
truncated and we get a misleading "error: bad packed object CRC for
..." as a result.
Use off_t for len and datalen. check_pack_crc() already accepts this
argument as off_t and can deal with 4+ GB.
Noticed-by: Christoph Michelbach <michelbach94@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix an unintended regression in v2.9 that breaks "clone --depth"
that recurses down to submodules by forcing the submodules to also
be cloned shallowly, which many server instances that host upstream
of the submodules are not prepared for.
* sb/clone-shallow-passthru:
clone: do not let --depth imply --shallow-submodules
The ownership rule for the piece of memory that hold references to
be fetched in "git fetch" was screwy, which has been cleaned up.
* km/fetch-do-not-free-remote-name:
builtin/fetch.c: don't free remote->name after fetch
Since 47f0b6d5 (Fall back to three-way merge when applying a patch.,
2005-10-06), i.e. for almost 11 years already, we used a male form
to describe "the other tree".
While it was unintended, this gave the erroneous impression as if
the Git developers thought of users as male, and were unaware of the
important role in software development played by female actors such
as Ada Lovelace, Grace Hopper and Margaret Hamilton. In fact, the
first professional software developers were all female.
Let's change those unfortunate references to the gender neutral
"their tree". Doing so also makes the fallback_merge_recursive(),
which is an oddball, more in line with the other parts of the system
where we contrast what we have vs what we obtain from others by
saying "ours" vs "theirs". This inconsistency was also unintended.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git update-index --add --chmod=+x file" may be usable as an escape
hatch, but not a friendly thing to force for people who do need to
use it regularly. "git add --chmod=+x file" can be used instead.
* et/add-chmod-x:
add: add --chmod=+x / --chmod=-x options
In exactly one callers (builtin/revert.c), we build up the
options list dynamically from multiple arrays. We do so by
manually inserting "filler" entries into one array, and then
copying the other array into the allocated space.
This is tedious and error-prone, as you have to adjust the
filler any time the second array is modified (although we do
at least check and die() when the counts do not match up).
Instead, let's just allocate a new array.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reverts commit 4d5520053 (grep: make it clear i-t-a entries are
ignored, 2015-12-27) and adds an alternative fix to maintain the -L
--cached behavior.
4d5520053 caused 'git grep' to no longer find matches in new files in
the working tree where the corresponding index entry had the "intent to
add" bit set, despite the fact that these files are tracked.
The content in the index of a file for which the "intent to add" bit is
set is considered indeterminate and not empty. For most grep queries we
want these to behave the same, however for -L --cached (files without a
match) we don't want to respond positively for "intent to add" files as
their contents are indeterminate. This is in contrast to files with
empty contents in the index (no lines implies no matches for any grep
query expression) which should be reported in the output of a grep -L
--cached invocation.
Add tests to cover this case and a few related cases which previously
lacked coverage.
Helped-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Charles Bailey <cbailey32@bloomberg.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When there are blank lines at the beginning of a commit message, the
pretty printing machinery already skips them when showing a commit
subject (or the complete commit message). We shall henceforth do the
same when reporting the commit subject after the user called
git reset --hard <commit>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Consistent with the pretty-printing machinery, we skip leading blank
lines (if any) of existing commit messages.
While Git itself only produces commit objects with a single empty line
between commit header and commit message, it is legal to have more than
one blank line (i.e. lines containing only white space, or no
characters) at the beginning of the commit message, and the
pretty-printing code already handles that.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git rev-list --count" whose walk-length is limited with "-n"
option did not work well with the counting optimized to look at the
bitmap index.
* jk/rev-list-count-with-bitmap:
rev-list: disable bitmaps when "-n" is used with listing objects
rev-list: "adjust" results of "--count --use-bitmap-index -n"
This matches the documentation and allows gc.autoPackLimit=1
to maintain a single pack without attempting a repack on every
"git gc --auto" invocation.
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In v2.9.0, we prematurely flipped the default to force cloning
submodules shallowly, when the superproject is getting cloned
shallowly. This is likely to fail when the upstream repositories
submodules are cloned from a repository that is not prepared to
serve histories that ends at a commit that is not at the tip of a
branch, and we know the world is not yet ready.
Use a safer default to clone the submodules fully, unless the user
tells us that she knows that the upstream repository of the
submodules are willing to cooperate with "--shallow-submodules"
option.
Noticed-by: Vadim Eisenberg <VADIME@il.ibm.com>
Helped-by: Jeff King <peff@peff.net>
Helped-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These callers appear to expect that deref_tag() is to peel one layer
of a tag, but the function does not work that way; it has its own
loop to unwrap tags until an object that is not a tag appears.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make fetch's string_list of remote names own all of its string items
(strdup'ing when necessary) so that it can deallocate them safely
when clearing.
Signed-off-by: Keith McGuigan <kmcguigan@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a follow up commit for f932729c (memoize common git-path
"constant" files, 10-Aug-2015).
The many function calls to git_path() are replaced by
git_path_commit_editmsg() and which thus eliminates the need to repeatedly
compute the location of "COMMIT_EDITMSG".
Mentored-by: Lars Schneider <larsxschneider@gmail.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The executable bit will not be detected (and therefore will not be
set) for paths in a repository with `core.filemode` set to false,
though the users may still wish to add files as executable for
compatibility with other users who _do_ have `core.filemode`
functionality. For example, Windows users adding shell scripts may
wish to add them as executable for compatibility with users on
non-Windows.
Although this can be done with a plumbing command
(`git update-index --add --chmod=+x foo`), teaching the `git-add`
command allows users to set a file executable with a command that
they're already familiar with.
Signed-off-by: Edward Thomson <ethomson@edwardthomson.com>
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Many commands normalize command line arguments from NFD to NFC
variant of UTF-8 on OSX, but commands in the "diff" family did
not, causing "git diff $path" to complain that no such path is
known to Git. They have been taught to do the normalization.
* ar/diff-args-osx-precompose:
diff: run arguments through precompose_argv
A bash-ism "local" has been removed from "git submodule" scripted
Porcelain.
* sb/submodule-helper-relative-path:
submodule: remove bashism from shell script
The way how "submodule--helper list" signals unmatch error to its
callers has been updated.
* sb/submodule-helper-list-signal-unmatch-via-exit-status:
submodule--helper: offer a consistent API
You can ask rev-list to use bitmaps to speed up an --objects
traversal, which should generally give you your answers much
faster.
Likewise, you can ask rev-list to limit such a traversal
with `-n`, in which case we'll show only a limited set of
commits (and only the tree and commit objects directly
reachable from those commits).
But if you do both together, the results are nonsensical. We
end up limiting any fallback traversal we do to _find_ the
bitmaps, but the actual set of objects we output will be
picked arbitrarily from the union of any bitmaps we do find,
and will involve the objects of many more commits.
It's possible that somebody might want this as a "show me
what you can, but limit the amount of work you do" flag.
But as with the prior commit clamping "--count", the results
are basically non-deterministic; you'll get the values from
some commits between `n` and the total number, and you can't
tell which.
And unlike the `--count` case, we can't easily generate the
"real" value from the bitmap values (you can't just walk
back `-n` commits and subtract out the reachable objects
from the boundary commits; the bitmaps for `X` record its
total reachability, so you don't know which objects are
directly from `X` itself, which from `X^`, and so on).
So let's just fallback to the non-bitmap code path in this
case, so we always give a sane answer.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you ask rev-list for:
git rev-list --count --use-bitmap-index HEAD
we optimize out the actual traversal and just give you the
number of bits set in the commit bitmap. This is faster,
which is good.
But if you ask to limit the size of the traversal, like:
git rev-list --count --use-bitmap-index -n 100 HEAD
we'll still output the full bitmapped number we found. On
the surface, that might even seem OK. You explicitly asked
to use the bitmap index, and it was cheap to compute the
real answer, so we gave it to you.
But there's something much more complicated going on under
the hood. If we don't have a bitmap directly for HEAD, then
we have to actually traverse backwards, looking for a
bitmapped commit. And _that_ traversal is bounded by our
`-n` count.
This is a good thing, because it bounds the work we have to
do, which is probably what the user wanted by asking for
`-n`. But now it makes the output quite confusing. You might
get many values:
- your `-n` value, if we walked back and never found a
bitmap (or fewer if there weren't that many commits)
- the actual full count, if we found a bitmap root for
every path of our traversal with in the `-n` limit
- any number in between! We might have walked back and
found _some_ bitmaps, but then cut off the traversal
early with some commits not accounted for in the result.
So you cannot even see a value higher than your `-n` and say
"OK, bitmaps kicked in, this must be the real full count".
The only sane thing is for git to just clamp the value to a
maximum of the `-n` value, which means we should output the
exact same results whether bitmaps are in use or not.
The test in t5310 demonstrates this by using `-n 1`.
Without this patch we fail in the full-bitmap case (where we
do not have to traverse at all) but _not_ in the
partial-bitmap case (where we have to walk down to find an
actual bitmap). With this patch, both cases just work.
I didn't implement the crazy in-between case, just because
it's complicated to set up, and is really a subset of the
full-count case, which we do cover.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
