Update various codepaths to avoid manually-counted malloc().
* jk/tighten-alloc: (22 commits)
ewah: convert to REALLOC_ARRAY, etc
convert ewah/bitmap code to use xmalloc
diff_populate_gitlink: use a strbuf
transport_anonymize_url: use xstrfmt
git-compat-util: drop mempcpy compat code
sequencer: simplify memory allocation of get_message
test-path-utils: fix normalize_path_copy output buffer size
fetch-pack: simplify add_sought_entry
fast-import: simplify allocation in start_packfile
write_untracked_extension: use FLEX_ALLOC helper
prepare_{git,shell}_cmd: use argv_array
use st_add and st_mult for allocation size computation
convert trivial cases to FLEX_ARRAY macros
use xmallocz to avoid size arithmetic
convert trivial cases to ALLOC_ARRAY
convert manual allocations to argv_array
argv-array: add detach function
add helpers for allocating flex-array structs
harden REALLOC_ARRAY and xcalloc against size_t overflow
tree-diff: catch integer overflow in combine_diff_path allocation
...
"git show 'HEAD:Foo[BAR]Baz'" did not interpret the argument as a
rev, i.e. the object named by the the pathname with wildcard
characters in a tree object.
* nd/dwim-wildcards-as-pathspecs:
get_sha1: don't die() on bogus search strings
check_filename: tighten dwim-wildcard ambiguity
checkout: reorder check_filename conditional
If our size computation overflows size_t, we may allocate a
much smaller buffer than we expected and overflow it. It's
probably impossible to trigger an overflow in most of these
sites in practice, but it is easy enough convert their
additions and multiplications into overflow-checking
variants. This may be fixing real bugs, and it makes
auditing the code easier.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A new "<branch>^{/!-<pattern>}" notation can be used to name a
commit that is reachable from <branch> that does not match the
given <pattern>.
* wp/sha1-name-negative-match:
object name: introduce '^{/!-<negative pattern>}' notation
test for '!' handling in rev-parse's named commits
The get_sha1() function generally returns an error code
rather than dying, and we sometimes speculatively call it
with something that may be a revision or a pathspec, in
order to see which one it might be.
If it sees a bogus ":/" search string, though, it complains,
without giving the caller the opportunity to recover. We can
demonstrate this in t6133 by looking for ":/*.t", which
should mean "*.t at the root of the tree", but instead dies
because of the invalid regex (the "*" has nothing to operate
on).
We can fix this by returning an error rather than calling
die(). Unfortunately, the tradeoff is that the error message
is slightly worse in cases where we _do_ know we have a rev.
E.g., running "git log ':/*.t' --" before yielded:
fatal: Invalid search pattern: *.t
and now we get only:
fatal: bad revision ':/*.t'
There's not a simple way to fix this short of passing a
"quiet" flag all the way through the get_sha1() stack.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To name a commit, you can now use the :/!-<negative pattern> regex
style, and consequentially, say
$ git rev-parse HEAD^{/!-foo}
and it will return the hash of the first commit reachable from HEAD,
whose commit message does not contain "foo". This is the opposite of the
existing <rev>^{/<pattern>} syntax.
The specific use-case this is intended for is to perform an operation,
excluding the most-recent commits containing a particular marker. For
example, if you tend to make "work in progress" commits, with messages
beginning with "WIP", you work, then it could be useful to diff against
"the most recent commit which was not a WIP commit". That sort of thing
now possible, via commands such as:
$ git diff @^{/!-^WIP}
The leader '/!-', rather than simply '/!', to denote a negative match,
is chosen to leave room for additional modifiers in the future.
Signed-off-by: Will Palmer <wmpalmer@gmail.com>
Signed-off-by: Stephen P. Smith <ischis2@cox.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert all instances of get_object_hash to use an appropriate reference
to the hash member of the oid member of struct object. This provides no
functional change, as it is essentially a macro substitution.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
struct object is one of the major data structures dealing with object
IDs. Convert it to use struct object_id instead of an unsigned char
array. Convert get_object_hash to refer to the new member as well.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
Convert most instances where the sha1 member of struct object is
dereferenced to use get_object_hash. Most instances that are passed to
functions that have versions taking struct object_id, such as
get_sha1_hex/get_oid_hex, or instances that can be trivially converted
to use struct object_id instead, are not converted.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
We dynamically allocate a buffer and then strcpy and strcat
into it. This isn't buggy, but we'd prefer to avoid these
suspicious functions.
This would be a good candidate for converstion to xstrfmt,
but we need to record the length for dealing with index
entries. A strbuf handles that for us.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We use sprintf() to format some hex data into a buffer. The
buffer is clearly long enough, and using snprintf here is
not necessary. And in fact, it does not really make anything
easier to audit, as the size we feed to snprintf accounts
for the magic extra 42 bytes found in each alt->name field
of struct alternate_object_database (which is there exactly
to do this formatting).
Still, it is nice to remove an sprintf call and replace it
with an xsnprintf and explanatory comment, which makes it
easier to audit the code base for overflows.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sha1_to_hex and find_unique_abbrev functions always
write into reusable static buffers. There are a few problems
with this:
- future calls overwrite our result. This is especially
annoying with find_unique_abbrev, which does not have a
ring of buffers, so you cannot even printf() a result
that has two abbreviated sha1s.
- if you want to put the result into another buffer, we
often strcpy, which looks suspicious when auditing for
overflows.
This patch introduces sha1_to_hex_r and find_unique_abbrev_r,
which write into a user-provided buffer. Of course this is
just punting on the overflow-auditing, as the buffer
obviously needs to be GIT_SHA1_HEXSZ + 1 bytes. But it is
much easier to audit, since that is a well-known size.
We retain the non-reentrant forms, which just become thin
wrappers around the reentrant ones. This patch also adds a
strbuf variant of find_unique_abbrev, which will be handy in
later patches.
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>
for_each_ref() callback functions were taught to name the objects
not with "unsigned char sha1[20]" but with "struct object_id".
* bc/object-id: (56 commits)
struct ref_lock: convert old_sha1 member to object_id
warn_if_dangling_symref(): convert local variable "junk" to object_id
each_ref_fn_adapter(): remove adapter
rev_list_insert_ref(): remove unneeded arguments
rev_list_insert_ref_oid(): new function, taking an object_oid
mark_complete(): remove unneeded arguments
mark_complete_oid(): new function, taking an object_oid
clear_marks(): rewrite to take an object_id argument
mark_complete(): rewrite to take an object_id argument
send_ref(): convert local variable "peeled" to object_id
upload-pack: rewrite functions to take object_id arguments
find_symref(): convert local variable "unused" to object_id
find_symref(): rewrite to take an object_id argument
write_one_ref(): rewrite to take an object_id argument
write_refs_to_temp_dir(): convert local variable sha1 to object_id
submodule: rewrite to take an object_id argument
shallow: rewrite functions to take object_id arguments
handle_one_ref(): rewrite to take an object_id argument
add_info_ref(): rewrite to take an object_id argument
handle_one_reflog(): rewrite to take an object_id argument
...
Introduce <branch>@{push} short-hand to denote the remote-tracking
branch that tracks the branch at the remote the <branch> would be
pushed to.
* jk/at-push-sha1:
for-each-ref: accept "%(push)" format
for-each-ref: use skip_prefix instead of starts_with
sha1_name: implement @{push} shorthand
sha1_name: refactor interpret_upstream_mark
sha1_name: refactor upstream_mark
remote.c: add branch_get_push
remote.c: return upstream name from stat_tracking_info
remote.c: untangle error logic in branch_get_upstream
remote.c: report specific errors from branch_get_upstream
remote.c: introduce branch_get_upstream helper
remote.c: hoist read_config into remote_get_1
remote.c: provide per-branch pushremote name
remote.c: hoist branch.*.remote lookup out of remote_get_1
remote.c: drop "remote" pointer from "struct branch"
remote.c: refactor setup of branch->merge list
remote.c: drop default_remote_name variable
"git cat-file --batch(-check)" learned the "--follow-symlinks"
option that follows an in-tree symbolic link when asked about an
object via extended SHA-1 syntax, e.g. HEAD:RelNotes that points at
Documentation/RelNotes/2.5.0.txt. With the new option, the command
behaves as if HEAD:Documentation/RelNotes/2.5.0.txt was given as
input instead.
* dt/cat-file-follow-symlinks:
cat-file: add --follow-symlinks to --batch
sha1_name: get_sha1_with_context learns to follow symlinks
tree-walk: learn get_tree_entry_follow_symlinks
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change typedef each_ref_fn to take a "const struct object_id *oid"
parameter instead of "const unsigned char *sha1".
To aid this transition, implement an adapter that can be used to wrap
old-style functions matching the old typedef, which is now called
"each_ref_sha1_fn"), and make such functions callable via the new
interface. This requires the old function and its cb_data to be
wrapped in a "struct each_ref_fn_sha1_adapter", and that object to be
used as the cb_data for an adapter function, each_ref_fn_adapter().
This is an enormous diff, but most of it consists of simple,
mechanical changes to the sites that call any of the "for_each_ref"
family of functions. Subsequent to this change, the call sites can be
rewritten one by one to use the new interface.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a triangular workflow, each branch may have two distinct
points of interest: the @{upstream} that you normally pull
from, and the destination that you normally push to. There
isn't a shorthand for the latter, but it's useful to have.
For instance, you may want to know which commits you haven't
pushed yet:
git log @{push}..
Or as a more complicated example, imagine that you normally
pull changes from origin/master (which you set as your
@{upstream}), and push changes to your own personal fork
(e.g., as myfork/topic). You may push to your fork from
multiple machines, requiring you to integrate the changes
from the push destination, rather than upstream. With this
patch, you can just do:
git rebase @{push}
rather than typing out the full name.
The heavy lifting is all done by branch_get_push; here we
just wire it up to the "@{push}" syntax.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that most of the logic for our local get_upstream_branch
has been pushed into the generic branch_get_upstream, we can
fold the remainder into interpret_upstream_mark.
Furthermore, what remains is generic to any branch-related
"@{foo}" we might add in the future, and there's enough
boilerplate that we'd like to reuse it. Let's parameterize
the two operations (parsing the mark and computing its
value) so that we can reuse this for "@{push}" in the near
future.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We will be adding new mark types in the future, so separate
the suffix data from the logic.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the previous commit introduced the branch_get_upstream
helper, there was one call-site that could not be converted:
the one in sha1_name.c, which gives detailed error messages
for each possible failure.
Let's teach the helper to optionally report these specific
errors. This lets us convert another callsite, and means we
can use the helper in other locations that want to give the
same error messages.
The logic and error messages come straight from sha1_name.c,
with the exception that we start each error with a lowercase
letter, as is our usual style (note that a few tests need
updated as a result).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Call file_exists() instead of open-coding it. That's shorter, simpler
and the intent becomes clearer.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Wire up get_sha1_with_context to call get_tree_entry_follow_symlinks
when GET_SHA1_FOLLOW_SYMLINKS is passed in flags. G_S_FOLLOW_SYMLINKS
is incompatible with G_S_ONLY_TO_DIE because the diagnosis
that ONLY_TO_DIE triggers does not at present consider symlinks, and
it would be a significant amount of additional code to allow it to
do so.
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the standard function isxdigit() to make the intent clearer and
avoid using magic constants.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code cleanups.
* rs/simple-cleanups:
sha1_name: use strlcpy() to copy strings
pretty: use starts_with() to check for a prefix
for-each-ref: use skip_prefix() to avoid duplicate string comparison
connect: use strcmp() for string comparison
Use strlcpy() instead of calling strncpy() and then setting the last
byte of the target buffer to NUL explicitly. This shortens and
simplifies the code a bit.
Signed-of-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_merge_bases*() API was easy to misuse by careless
copy&paste coders, leaving object flags tainted in the commits that
needed to be traversed.
* jc/merge-bases:
get_merge_bases(): always clean-up object flags
bisect: clean flags after checking merge bases
The code to abbreviate an object name to its short unique prefix
has been optimized when no abbreviation was requested.
* mh/find-uniq-abbrev:
sha1_name: avoid unnecessary sha1 lookup in find_unique_abbrev
An example where this happens is when doing an ls-tree on a tree that
contains a commit link. In that case, find_unique_abbrev is called
to get a non-abbreviated hex sha1, but still, a lookup is done as
to whether the sha1 is in the repository (which ends up looking for
a loose object in .git/objects), while the result of that lookup is
not used when returning a non-abbreviated hex sha1.
Signed-off-by: Mike Hommey <mh@glandium.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The callers of get_merge_bases() can choose to leave object flags
used during the merge-base traversal by passing cleanup=0 as a
parameter, but in practice a very few callers can afford to do so
(namely, "git merge-base"), as they need to compute merge base in
preparation for other processing of their own and they need to see
the object without contaminate flags.
Change the function signature of get_merge_bases_many() and
get_merge_bases() to drop the cleanup parameter, so that the
majority of the callers do not have to say ", 1" at the end.
Give a new get_merge_bases_many_dirty() API to support only a few
callers that know they do not need to spend cycles cleaning up the
object flags.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a reflog is deleted, e.g. when "git stash" clears its stashes,
"git rev-parse --verify --quiet" dies:
fatal: Log for refs/stash is empty.
The reason is that the get_sha1() code path does not allow us
to suppress this message.
Pass the flags bitfield through get_sha1_with_context() so that
read_ref_at() can suppress the message.
Use get_sha1_with_context1() instead of get_sha1() in rev-parse
so that the --quiet flag is honored.
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a couple of "accumulate into a sorted list" to "accumulate and
then sort the list".
* rs/list-optim:
walker: avoid quadratic list insertion in mark_complete
sha1_name: avoid quadratic list insertion in handle_one_ref
Similar to 16445242 (fetch-pack: avoid quadratic list insertion in
mark_complete), sort only after all refs are collected instead of while
inserting. The result is the same, but it's more efficient that way.
The difference will only be measurable in repositories with a large
number of refs.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A call to "dwim_ref(name, len, flags, &ref)" will allocate a
new string in "ref" to return the exact ref we found. We do
not consistently free it in all code paths, leading to small
leaks. The worst is in get_sha1_basic, which may be called
many times (e.g., by "cat-file --batch"), though it is
relatively unlikely, as it only triggers on a bogus reflog
specification.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jk/xstrfmt:
setup_git_env(): introduce git_path_from_env() helper
unique_path: fix unlikely heap overflow
walker_fetch: fix minor memory leak
merge: use argv_array when spawning merge strategy
sequencer: use argv_array_pushf
setup_git_env: use git_pathdup instead of xmalloc + sprintf
use xstrfmt to replace xmalloc + strcpy/strcat
use xstrfmt to replace xmalloc + sprintf
use xstrdup instead of xmalloc + strcpy
use xstrfmt in favor of manual size calculations
strbuf: add xstrfmt helper
* jk/skip-prefix:
http-push: refactor parsing of remote object names
imap-send: use skip_prefix instead of using magic numbers
use skip_prefix to avoid repeated calculations
git: avoid magic number with skip_prefix
fetch-pack: refactor parsing in get_ack
fast-import: refactor parsing of spaces
stat_opt: check extra strlen call
daemon: use skip_prefix to avoid magic numbers
fast-import: use skip_prefix for parsing input
use skip_prefix to avoid repeating strings
use skip_prefix to avoid magic numbers
transport-helper: avoid reading past end-of-string
fast-import: fix read of uninitialized argv memory
apply: use skip_prefix instead of raw addition
refactor skip_prefix to return a boolean
avoid using skip_prefix as a boolean
daemon: mark some strings as const
parse_diff_color_slot: drop ofs parameter
It's a common idiom to match a prefix and then skip past it
with strlen, like:
if (starts_with(foo, "bar"))
foo += strlen("bar");
This avoids magic numbers, but means we have to repeat the
string (and there is no compiler check that we didn't make a
typo in one of the strings).
We can use skip_prefix to handle this case without repeating
ourselves.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's easy to get manual allocation calculations wrong, and
the use of strcpy/strcat raise red flags for people looking
for buffer overflows (though in this case each site was
fine).
It's also shorter to use xstrfmt, and the printf-format
tends to be easier for a reader to see what the final string
will look like.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most callsites which use the commit buffer try to use the
cached version attached to the commit, rather than
re-reading from disk. Unfortunately, that interface provides
only a pointer to the NUL-terminated buffer, with no
indication of the original length.
For the most part, this doesn't matter. People do not put
NULs in their commit messages, and the log code is happy to
treat it all as a NUL-terminated string. However, some code
paths do care. For example, when checking signatures, we
want to be very careful that we verify all the bytes to
avoid malicious trickery.
This patch just adds an optional "size" out-pointer to
get_commit_buffer and friends. The existing callers all pass
NULL (there did not seem to be any obvious sites where we
could avoid an immediate strlen() call, though perhaps with
some further refactoring we could).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For both of these sites, we already do the "fallback to
read_sha1_file" trick. But we can shorten the code by just
using get_commit_buffer.
Note that the error cases are slightly different when
read_sha1_file fails. get_commit_buffer will die() if the
object cannot be loaded, or is a non-commit.
For get_sha1_oneline, this will almost certainly never
happen, as we will have just called parse_object (and if it
does, it's probably worth complaining about).
For record_author_date, the new behavior is probably better;
we notify the user of the error instead of silently ignoring
it. And because it's used only for sorting by author-date,
somebody examining a corrupt repo can fallback to the
regular traversal order.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Attempts to show where a single-strand-of-pearls break in "git log"
output.
* nd/log-show-linear-break:
log: add --show-linear-break to help see non-linear history
object.h: centralize object flag allocation
While the field "flags" is mainly used by the revision walker, it is
also used in many other places. Centralize the whole flag allocation to
one place for a better overview (and easier to move flags if we have
too).
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
