Fix a handful of bugs around interpreting $branch@{upstream}
notation and its lookalike, when $branch part has interesting
characters, e.g. "@", and ":".
* jk/interpret-branch-name-fix:
interpret_branch_name: find all possible @-marks
interpret_branch_name: avoid @{upstream} past colon
interpret_branch_name: always respect "namelen" parameter
interpret_branch_name: rename "cp" variable to "at"
interpret_branch_name: factor out upstream handling
When we parse a string like "foo@{upstream}", we look for
the first "@"-sign, and check to see if it is an upstream
mark. However, since branch names can contain an @, we may
also see "@foo@{upstream}". In this case, we check only the
first @, and ignore the second. As a result, we do not find
the upstream.
We can solve this by iterating through all @-marks in the
string, and seeing if any is a legitimate upstream or
empty-at mark.
Another strategy would be to parse from the right-hand side
of the string. However, that does not work for the
"empty_at" case, which allows "@@{upstream}". We need to
find the left-most one in this case (and we then recurse as
"HEAD@{upstream}").
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
get_sha1() cannot currently parse a valid object name like
"HEAD:@{upstream}" (assuming that such an oddly named file
exists in the HEAD commit). It takes two passes to parse the
string:
1. It first considers the whole thing as a ref, which
results in looking for the upstream of "HEAD:".
2. It finds the colon, parses "HEAD" as a tree-ish, and then
finds the path "@{upstream}" in the tree.
For a path that looks like a normal reflog (e.g.,
"HEAD:@{yesterday}"), the first pass is a no-op. We try to
dwim_ref("HEAD:"), that returns zero refs, and we proceed
with colon-parsing.
For "HEAD:@{upstream}", though, the first pass ends up in
interpret_upstream_mark, which tries to find the branch
"HEAD:". When it sees that the branch does not exist, it
actually dies rather than returning an error to the caller.
As a result, we never make it to the second pass.
One obvious way of fixing this would be to teach
interpret_upstream_mark to simply report "no, this isn't an
upstream" in such a case. However, that would make the
error-reporting for legitimate upstream cases significantly
worse. Something like "bogus@{upstream}" would simply report
"unknown revision: bogus@{upstream}", while the current code
diagnoses a wide variety of possible misconfigurations (no
such branch, branch exists but does not have upstream, etc).
However, we can take advantage of the fact that a branch
name cannot contain a colon. Therefore even if we find an
upstream mark, any prefix with a colon must mean that
the upstream mark we found is actually a pathname, and
should be disregarded completely. This patch implements that
logic.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
interpret_branch_name gets passed a "name" buffer to parse,
along with a "namelen" parameter representing its length. If
"namelen" is zero, we fallback to the NUL-terminated
string-length of "name".
However, it does not necessarily follow that if we have
gotten a non-zero "namelen", it is the NUL-terminated
string-length of "name". E.g., when get_sha1() is parsing
"foo:bar", we will be asked to operate only on the first
three characters.
Yet in interpret_branch_name and its helpers, we use string
functions like strchr() to operate on "name", looking past
the length we were given. This can result in us mis-parsing
object names. We should instead be limiting our search to
"namelen" bytes.
There are three distinct types of object names this patch
addresses:
- The intrepret_empty_at helper uses strchr to find the
next @-expression after our potential empty-at. In an
expression like "@:foo@bar", it erroneously thinks that
the second "@" is relevant, even if we were asked only
to look at the first character. This case is easy to
trigger (and we test it in this patch).
- When finding the initial @-mark for @{upstream}, we use
strchr. This means we might treat "foo:@{upstream}" as
the upstream for "foo:", even though we were asked only
to look at "foo". We cannot test this one in practice,
because it is masked by another bug (which is fixed in
the next patch).
- The interpret_nth_prior_checkout helper did not receive
the name length at all. This turns out not to be a
problem in practice, though, because its parsing is so
limited: it always starts from the far-left of the
string, and will not tolerate a colon (which is
currently the only way to get a smaller-than-strlen
"namelen"). However, it's still worth fixing to make the
code more obviously correct, and to future-proof us
against callers with more exotic buffers.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the original version of this function, "cp" acted as a
pointer to many different things. Since the refactoring in
the last patch, it only marks the at-sign in the string.
Let's use a more descriptive variable name.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function checks a few different @{}-constructs. The
early part checks for and dispatches us to helpers for each
construct, but the code for handling @{upstream} is inline.
Let's factor this out into its own function. This makes
interpret_branch_name more readable, and will make it much
simpler to further refactor the function in future patches.
While we're at it, let's also break apart the refactored
code into a few helper functions. These will be useful if we
eventually implement similar @{upstream}-like constructs.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When parsing a 40-hex string into the object name, the string is
checked to see if it can be interpreted as a ref so that a warning
can be given for ambiguity. The code kicked in even when the
core.warnambiguousrefs is set to false to squelch this warning, in
which case the cycles spent to look at the ref namespace were an
expensive no-op, as the result was discarded without being used.
* br/sha1-name-40-hex-no-disambiguation:
sha1_name: don't resolve refs when core.warnambiguousrefs is false
When seeing a full 40-hex object name, get_sha1_basic()
unconditionally checks if the string can also be interpreted as a
refname, but the result will not be used unless warn_ambiguous_refs
is in effect.
Omitting this unnecessary ref resolution provides a substantial
performance improvement, especially when passing many hashes to a
command (like "git rev-list --stdin") and core.warnambiguousrefs is
set to false. The check incurs 6 stat()s for every hash supplied,
which can be costly over NFS.
Signed-off-by: Brodie Rao <brodie@sf.io>
Acked-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove a few duplicate implementations of prefix/suffix comparison
functions, and rename them to starts_with and ends_with.
* cc/starts-n-ends-with:
replace {pre,suf}fixcmp() with {starts,ends}_with()
strbuf: introduce starts_with() and ends_with()
builtin/remote: remove postfixcmp() and use suffixcmp() instead
environment: normalize use of prefixcmp() by removing " != 0"
Leaving only the function definitions and declarations so that any
new topic in flight can still make use of the old functions, replace
existing uses of the prefixcmp() and suffixcmp() with new API
functions.
The change can be recreated by mechanically applying this:
$ git grep -l -e prefixcmp -e suffixcmp -- \*.c |
grep -v strbuf\\.c |
xargs perl -pi -e '
s|!prefixcmp\(|starts_with\(|g;
s|prefixcmp\(|!starts_with\(|g;
s|!suffixcmp\(|ends_with\(|g;
s|suffixcmp\(|!ends_with\(|g;
'
on the result of preparatory changes in this series.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jk/robustify-parse-commit:
checkout: do not die when leaving broken detached HEAD
use parse_commit_or_die instead of custom message
use parse_commit_or_die instead of segfaulting
assume parse_commit checks for NULL commit
assume parse_commit checks commit->object.parsed
log_tree_diff: die when we fail to parse a commit
The parse_commit function will check whether it was passed a
NULL commit pointer, and if so, return an error. There is no
need for callers to check this separately.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of typing four capital letters "HEAD", you can say "@" now,
e.g. "git log @".
* fc/at-head:
Add new @ shortcut for HEAD
sha1-name: pass len argument to interpret_branch_name()
Make "foo^{tag}" to peel a tag to itself, i.e. no-op., and fail if
"foo" is not a tag. "git rev-parse --verify v1.0^{tag}" would be a
more convenient way to say "test $(git cat-file -t v1.0) = tag".
* rh/peeling-tag-to-tag:
peel_onion: do not assume length of x_type globals
peel_onion(): add support for <rev>^{tag}
Typing 'HEAD' is tedious, especially when we can use '@' instead.
The reason for choosing '@' is that it follows naturally from the
ref@op syntax (e.g. HEAD@{u}), except we have no ref, and no
operation, and when we don't have those, it makes sens to assume
'HEAD'.
So now we can use 'git show @~1', and all that goody goodness.
Until now '@' was a valid name, but it conflicts with this idea, so
let's make it invalid. Probably very few people, if any, used this name.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Replace 'committish' in documentation and comments with 'commit-ish'
to match gitglossary(7) and to be consistent with 'tree-ish'.
The only remaining instances of 'committish' are:
* variable, function, and macro names
* "(also committish)" in the definition of commit-ish in
gitglossary[7]
Signed-off-by: Richard Hansen <rhansen@bbn.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we are parsing "rev^{foo}", we check "foo" against the
various global type strings, like "commit_type",
"tree_type", etc. This is nicely abstracted, but then we
destroy the abstraction completely by using magic numbers
that must match the length of the type strings.
We could avoid these magic numbers by using skip_prefix. But
taking a step back, we can realize that using the
"commit_type" global is not really buying us anything. It is
not ever going to change from being "commit" without causing
severe breakage to existing uses. And even if it did change
for some crazy reason, we would want to evaluate its effects
on the "rev^{}" syntax, anyway.
Let's just switch these to using a custom string literal, as
we do for "rev^{object}". The resulting code is more robust
to changes in the type strings, and is more readable.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Complete the <rev>^{<type>} family of object descriptors by having
<rev>^{tag} dereference <rev> until a tag object is found (or fail if
unable).
At first glance this may not seem very useful, as commits, trees, and
blobs cannot be peeled to a tag, and a tag would just peel to itself.
However, this can be used to ensure that <rev> names a tag object:
$ git rev-parse --verify v1.8.4^{tag}
04f013dc38d7512eadb915eba22efc414f18b869
$ git rev-parse --verify master^{tag}
error: master^{tag}: expected tag type, but the object dereferences to tree type
fatal: Needed a single revision
Users can already ensure that <rev> is a tag object by checking the
output of 'git cat-file -t <rev>', but:
* users may expect <rev>^{tag} to exist given that <rev>^{commit},
<rev>^{tree}, and <rev>^{blob} all exist
* this syntax is more convenient/natural in some circumstances
Signed-off-by: Richard Hansen <rhansen@bbn.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is useful to make sure we don't step outside the boundaries of what
we are interpreting at the moment. For example while interpreting
foobar@{u}~1, the job of interpret_branch_name() ends right before ~1,
but there's no way to figure that out inside the function, unless the
len argument is passed.
So let's do that.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reverts commit cdfd94837b, as it
does not just apply to "@" (and forms with modifiers like @{u}
applied to it), but also affects e.g. "refs/heads/@/foo", which it
shouldn't.
The basic idea of giving a short-hand might be good, and the topic
can be retried later, but let's revert to avoid affecting existing
use cases for now for the upcoming release.
We spell config variables in camelCase instead of with_underscores.
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If somebody wants to only know on-disk footprint of an object
without having to know its type or payload size, we can bypass a
lot of code to cheaply learn it.
* jk/cat-file-batch-optim:
Fix some sparse warnings
sha1_object_info_extended: pass object_info to helpers
sha1_object_info_extended: make type calculation optional
packed_object_info: make type lookup optional
packed_object_info: hoist delta type resolution to helper
sha1_loose_object_info: make type lookup optional
sha1_object_info_extended: rename "status" to "type"
cat-file: disable object/refname ambiguity check for batch mode
A common use of "cat-file --batch-check" is to feed a list
of objects from "rev-list --objects" or a similar command.
In this instance, all of our input objects are 40-byte sha1
ids. However, cat-file has always allowed arbitrary revision
specifiers, and feeds the result to get_sha1().
Fortunately, get_sha1() recognizes a 40-byte sha1 before
doing any hard work trying to look up refs, meaning this
scenario should end up spending very little time converting
the input into an object sha1. However, since 798c35f
(get_sha1: warn about full or short object names that look
like refs, 2013-05-29), when we encounter this case, we
spend the extra effort to do a refname lookup anyway, just
to print a warning. This is further exacerbated by ca91993
(get_packed_ref_cache: reload packed-refs file when it
changes, 2013-06-20), which makes individual ref lookup more
expensive by requiring a stat() of the packed-refs file for
each missing ref.
With no patches, this is the time it takes to run:
$ git rev-list --objects --all >objects
$ time git cat-file --batch-check='%(objectname)' <objects
on the linux.git repository:
real 1m13.494s
user 0m25.924s
sys 0m47.532s
If we revert ca91993, the packed-refs up-to-date check, it
gets a little better:
real 0m54.697s
user 0m21.692s
sys 0m32.916s
but we are still spending quite a bit of time on ref lookup
(and we would not want to revert that patch, anyway, which
has correctness issues). If we revert 798c35f, disabling
the warning entirely, we get a much more reasonable time:
real 0m7.452s
user 0m6.836s
sys 0m0.608s
This patch does the moral equivalent of this final case (and
gets similar speedups). We introduce a global flag that
callers of get_sha1() can use to avoid paying the price for
the warning.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A test that should have failed but didn't revealed a bug that needs
to be corrected.
* jc/t1512-fix:
get_short_sha1(): correctly disambiguate type-limited abbreviation
t1512: correct leftover constants from earlier edition
I attempted to make index_state->cache[] a "const struct cache_entry **"
to find out how existing entries in index are modified and where. The
question I have is what do we do if we really need to keep track of on-disk
changes in the index. The result is
- diff-lib.c: setting CE_UPTODATE
- name-hash.c: setting CE_HASHED
- preload-index.c, read-cache.c, unpack-trees.c and
builtin/update-index: obvious
- entry.c: write_entry() may refresh the checked out entry via
fill_stat_cache_info(). This causes "non-const struct cache_entry
*" in builtin/apply.c, builtin/checkout-index.c and
builtin/checkout.c
- builtin/ls-files.c: --with-tree changes stagemask and may set
CE_UPDATE
Of these, write_entry() and its call sites are probably most
interesting because it modifies on-disk info. But this is stat info
and can be retrieved via refresh, at least for porcelain
commands. Other just uses ce_flags for local purposes.
So, keeping track of "dirty" entries is just a matter of setting a
flag in index modification functions exposed by read-cache.c. Except
unpack-trees, the rest of the code base does not do anything funny
behind read-cache's back.
The actual patch is less valueable than the summary above. But if
anyone wants to re-identify the above sites. Applying this patch, then
this:
diff --git a/cache.h b/cache.h
index 430d021..1692891 100644
--- a/cache.h
+++ b/cache.h
@@ -267,7 +267,7 @@ static inline unsigned int canon_mode(unsigned int mode)
#define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)
struct index_state {
- struct cache_entry **cache;
+ const struct cache_entry **cache;
unsigned int version;
unsigned int cache_nr, cache_alloc, cache_changed;
struct string_list *resolve_undo;
will help quickly identify them without bogus warnings.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One test in t1512 that expects a failure incorrectly passed. The
test prepares a commit whose object name begins with ten "0"s, and
also prepares a tag that points at the commit. The object name of
the tag also begins with ten "0"s. There is no other commit-ish
object in the repository whose name begins with such a prefix.
Ideally, in such a repository:
$ git rev-parse --verify 0000000000^{commit}
should yield that commit. If 0000000000 is taken as the commit
0000000000e4f, peeling it to a commmit yields that commit itself,
and if 0000000000 is taken as the tag 0000000000f8f, peeling it to a
commit also yields the same commit, so in that twisted sense, the
extended SHA-1 expression 0000000000^{commit} is unambigous. The
test that expects a failure is to check the above command.
The reason the test expects a failure is that we did not implement
such a "unification" of two candidate objects. What we did (or at
least, meant to) implement was to recognise that a commit-ish is
required to expand 0000000000, and notice that there are two succh
commit-ish, and diagnose the request as ambiguous.
However, there was a bug in the logic to check the candidate
objects. When the code saw 0000000000f8f (a tag) that shared the
shortened prefix (ten "0"s), it tried to make sure that the tag is a
commit-ish by looking at the tag object. Because it incorrectly
used lookup_object() when the tag has not been parsed, however, we
incorrectly declared that the tag is _not_ a commit-ish, leaving the
sole commit in the repository, 0000000000e4f, that has the required
prefix as "unique match", causing the test to pass when it shouldn't.
This fixes the logic to inspect the type of the object a tag refers
to, to make the test that is expected to fail correctly fail.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git cmd <name>", when <name> happens to be a 40-hex string,
directly uses the 40-hex string as an object name, even if a ref
"refs/<some hierarchy>/<name>" exists. This disambiguation order
is unlikely to change, but we should warn about the ambiguity just
like we warn when more than one refs/ hierachies share the same
name.
* nd/warn-ambiguous-object-name:
get_sha1: warn about full or short object names that look like refs
When a reflog notation is used for implicit "current branch", we
did not say which branch and worse said "branch ''".
* rr/die-on-missing-upstream:
sha1_name: fix error message for @{<N>}, @{<date>}
sha1_name: fix error message for @{u}
Currently, when we try to resolve @{<N>} or @{<date>} when the reflog
doesn't go back far enough, we get errors like:
# on branch master
$ git show @{10000}
fatal: Log for '' only has 7 entries.
$ git show @{10000.days.ago}
warning: Log for '' only goes back to Tue, 21 May 2013 14:14:45 +0530.
...
# detached HEAD case
$ git show @{10000}
fatal: Log for '' only has 2005 entries.
$ git show master@{10000}
fatal: Log for 'master' only has 7 entries.
The empty string '' is confusing and does not convey information
about whose logs we are inspecting. Change this so that we get:
# on branch master
$ git show @{10000}
fatal: Log for 'master' only has 7 entries.
$ git show @{10000.days.ago}
warning: Log for 'master' only goes back to Tue, 21 May 2013 14:14:45 +0530.
...
# detached HEAD case
$ git show @{10000}
fatal: Log for 'HEAD' only has 2005 entries.
$ git show master@{10000}
fatal: Log for 'master' only has 7 entries.
Also one of the message strings given to die() now points into
real_ref that was not used in that fashion, so stop freeing the
underlying storage for it.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Bug-spotted-and-fixed-by: Thomas Rast
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we get 40 hex digits, we immediately assume it's an SHA-1. This
is the right thing to do because we have no way else to specify an
object. If there is a ref with the same object name, it will be
ignored. Warn the user about this case because the ref with full
object name is likely a mistake, for example
git checkout -b $empty_var $(git rev-parse something)
advice.object_name_warning is not documented because frankly people
should not be aware about it until they encounter this situation.
While at there, warn about ambiguation with abbreviated SHA-1 too.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, when no (valid) upstream is configured for a branch, you get
an error like:
$ git show @{u}
error: No upstream configured for branch 'upstream-error'
error: No upstream configured for branch 'upstream-error'
fatal: ambiguous argument '@{u}': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
The "error: " line actually appears twice, and the rest of the error
message is useless. In sha1_name.c:interpret_branch_name(), there is
really no point in processing further if @{u} couldn't be resolved, and
we might as well die() instead of returning an error(). After making
this change, you get:
$ git show @{u}
fatal: No upstream configured for branch 'upstream-error'
Also tweak a few tests in t1507 to expect this output.
This only turns error() that may be called after we know we are
dealing with an @{upstream} marker into die(), without touching
silent error returns "return -1" from the function. Any caller that
wants to handle an error condition itself will not be hurt by this
change, unless they want to see the message from error() and then
exit silently without giving its own message, which needs to be
fixed anyway.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you were on 'frotz' branch before you checked out your current
branch, "git merge @{-1}~22" means the same as "git merge frotz~22".
The strbuf_branchname() function, when interpret_branch_name() gives
up resolving "@{-1}~22" fully, returns "frotz" and tells the caller
that it only resolved "@{-1}" part of the input, mistakes this as a
total failure, and appends the whole thing to the result, yielding
"frotz@{-1}~22", which does not make any sense.
Inspect the return value from interpret_branch_name() a bit more
carefully. When it errored out without consuming anything, we will
get -1 and we should return the whole thing. Otherwise, we should
append the remainder (i.e. "~22" in the earlier example) to the
partially resolved name (i.e. "frotz").
The test suite adds enough number of checkout to make @{-12} in the
last test in t0100 that tried to check "we haven't flipped branches
that many times" error case succeed; raise the number to a hundred.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
And restructure the if/else to factor out the common "is len positive?"
test into a single conditional.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Typing 'HEAD' is tedious, especially when we can use '@' instead.
The reason for choosing '@' is that it follows naturally from the
ref@op syntax (e.g. HEAD@{u}), except we have no ref, and no
operation, and when we don't have those, it makes sens to assume
'HEAD'.
So now we can use 'git show @~1', and all that goody goodness.
Until now '@' was a valid name, but it conflicts with this idea, so
let's make it invalid. Probably very few people, if any, used this name.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This code essentially replaces part of ref with another ref, for example
'@{-1}@{u}' is replaced with 'master@{u}', but this can be reused for
other purposes other than nth prior checkouts.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's trivial to check for them in the @{N} parsing loop.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Through the years the functionality to handle @{-N} and @{u} has moved
around the code, and as a result, code that once made sense, doesn't any
more.
There is no need to call this function recursively with the branch of
@{-N} substituted because dwim_{ref,log} already replaces it.
However, there's one corner-case where @{-N} resolves to a detached
HEAD, in which case we wouldn't get any ref back.
So we parse the nth-prior manually, and deal with it depending on
whether it's a SHA-1, or a ref.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The @-parsing loop unnecessarily checks for the sequence "@{" from
(len - 2) unnecessarily. We can safely check from (len - 4).
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
'at' is always 0, since we can reach this point only if
!len && reflog_len, and len=at when reflog is assigned.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There was no good way to ask "I have a random string that came from
outside world. I want to turn it into a 40-hex object name while
making sure such an object exists". A new peeling suffix ^{object}
can be used for that purpose, together with "rev-parse --verify".
* jc/sha1-name-object-peeler:
peel_onion(): teach $foo^{object} peeler
peel_onion: disambiguate to favor tree-ish when we know we want a tree-ish
A string that names an object can be suffixed with ^{type} peeler to
say "I have this object name; peel it until you get this type. If
you cannot do so, it is an error". v1.8.2^{commit} asks for a commit
that is pointed at an annotated tag v1.8.2; v1.8.2^{tree} unwraps it
further to the top-level tree object. A special suffix ^{} (i.e. no
type specified) means "I do not care what it unwraps to; just peel
annotated tag until you get something that is not a tag".
When you have a random user-supplied string, you can turn it to a
bare 40-hex object name, and cause it to error out if such an object
does not exist, with:
git rev-parse --verify "$userstring^{}"
for most objects, but this does not yield the tag object name when
$userstring refers to an annotated tag.
Introduce a new suffix, ^{object}, that only makes sure the given
name refers to an existing object. Then
git rev-parse --verify "$userstring^{object}"
becomes a way to make sure $userstring refers to an existing object.
This is necessary because the plumbing "rev-parse --verify" is only
about "make sure the argument is something we can feed to get_sha1()
and turn it into a raw 20-byte object name SHA-1" and is not about
"make sure that 20-byte object name SHA-1 refers to an object that
exists in our object store". When the given $userstring is already
a 40-hex, by definition "rev-parse --verify $userstring" can turn it
into a raw 20-byte object name. With "$userstring^{object}", we can
make sure that the 40-hex string names an object that exists in our
object store before "--verify" kicks in.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function already knows when interpreting $foo^{commit} to tell
the underlying get_sha1_1() to expect a commit-ish while evaluating
$foo. Teach it to do the same when asked for $foo^{tree}; we are
expecting a tree-ish and $foo should be disambiguated in favor of a
tree-ish, discarding a possible ambiguous match with a blob object.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
An internal function used to implement "git checkout @{-1}" was
hard to use correctly.
* jc/reflog-reverse-walk:
refs.c: fix fread error handling
reflog: add for_each_reflog_ent_reverse() API
for_each_recent_reflog_ent(): simplify opening of a reflog file
for_each_reflog_ent(): extract a helper to process a single entry
