Error messages from "git push" can be painted for more visibility.
* js/colored-push-errors:
config: document the settings to colorize push errors/hints
push: test to verify that push errors are colored
push: colorize errors
color: introduce support for colorizing stderr
The beginning of the next-gen transfer protocol.
* bw/protocol-v2: (35 commits)
remote-curl: don't request v2 when pushing
remote-curl: implement stateless-connect command
http: eliminate "# service" line when using protocol v2
http: don't always add Git-Protocol header
http: allow providing extra headers for http requests
remote-curl: store the protocol version the server responded with
remote-curl: create copy of the service name
pkt-line: add packet_buf_write_len function
transport-helper: introduce stateless-connect
transport-helper: refactor process_connect_service
transport-helper: remove name parameter
connect: don't request v2 when pushing
connect: refactor git_connect to only get the protocol version once
fetch-pack: support shallow requests
fetch-pack: perform a fetch using v2
upload-pack: introduce fetch server command
push: pass ref prefixes when pushing
fetch: pass ref prefixes when fetching
ls-remote: pass ref prefixes when requesting a remote's refs
transport: convert transport_get_remote_refs to take a list of ref prefixes
...
This is an attempt to resolve an issue I experience with people that are
new to Git -- especially colleagues in a team setting -- where they miss
that their push to a remote location failed because the failure and
success both return a block of white text.
An example is if I push something to a remote repository and then a
colleague attempts to push to the same remote repository and the push
fails because it requires them to pull first, but they don't notice
because a success and failure both return a block of white text. They
then continue about their business, thinking it has been successfully
pushed.
This patch colorizes the errors and hints (in red and yellow,
respectively) so whenever there is a failure when pushing to a remote
repository that fails, it is more noticeable.
[jes: fixed a couple bugs, added the color.{advice,push,transport}
settings, refactored to use want_color_stderr().]
Signed-off-by: Ryan Dammrose ryandammrose@gmail.com
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refactoring the internal global data structure to make it possible
to open multiple repositories, work with and then close them.
Rerolled by Duy on top of a separate preliminary clean-up topic.
The resulting structure of the topics looked very sensible.
* sb/object-store: (27 commits)
sha1_file: allow sha1_loose_object_info to handle arbitrary repositories
sha1_file: allow map_sha1_file to handle arbitrary repositories
sha1_file: allow map_sha1_file_1 to handle arbitrary repositories
sha1_file: allow open_sha1_file to handle arbitrary repositories
sha1_file: allow stat_sha1_file to handle arbitrary repositories
sha1_file: allow sha1_file_name to handle arbitrary repositories
sha1_file: add repository argument to sha1_loose_object_info
sha1_file: add repository argument to map_sha1_file
sha1_file: add repository argument to map_sha1_file_1
sha1_file: add repository argument to open_sha1_file
sha1_file: add repository argument to stat_sha1_file
sha1_file: add repository argument to sha1_file_name
sha1_file: allow prepare_alt_odb to handle arbitrary repositories
sha1_file: allow link_alt_odb_entries to handle arbitrary repositories
sha1_file: add repository argument to prepare_alt_odb
sha1_file: add repository argument to link_alt_odb_entries
sha1_file: add repository argument to read_info_alternates
sha1_file: add repository argument to link_alt_odb_entry
sha1_file: add raw_object_store argument to alt_odb_usable
pack: move approximate object count to object store
...
Migrate the struct alternate_object_database and all its related
functions to the object store as these functions are easier found in
that header. The migration is just a verbatim copy, no need to
include the object store header at any C file, because cache.h includes
repository.h which in turn includes the object-store.h
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce the transport-helper capability 'stateless-connect'. This
capability indicates that the transport-helper can be requested to run
the 'stateless-connect' command which should attempt to make a
stateless connection with a remote end. Once established, the
connection can be used by the git client to communicate with
the remote end natively in a stateless-rpc manner as supported by
protocol v2. This means that the client must send everything the server
needs in a single request as the client must not assume any
state-storing on the part of the server or transport.
If a stateless connection cannot be established then the remote-helper
will respond in the same manner as the 'connect' command indicating that
the client should fallback to using the dumb remote-helper commands.
A future patch will implement the 'stateless-connect' capability in our
http remote-helper (remote-curl) so that protocol v2 can be used using
the http transport.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When communicating with a v2 server, perform a fetch by requesting the
'fetch' command.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Construct a list of ref prefixes to be passed to 'get_refs_list()' from
the refspec to be used during the push. This list of ref prefixes will
be used to allow the server to filter the ref advertisement when
communicating using protocol v2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach transport_get_remote_refs() to accept a list of ref prefixes,
which will be sent to the server for use in filtering when using
protocol v2. (This list will be ignored when not using protocol v2.)
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the 'struct transport' virtual function 'get_refs_list()' to
optionally take an argv_array of ref prefixes. When communicating with
a server using protocol v2 these ref prefixes can be sent when
requesting a listing of their refs allowing the server to filter the
refs it sends based on the sent prefixes. This list will be ignored
when not using protocol v2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach the client to be able to request a remote's refs using protocol
v2. This is done by having a client issue a 'ls-refs' request to a v2
server.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce protocol_v2, a new value for 'enum protocol_version'.
Subsequent patches will fill in the implementation of protocol_v2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Once protocol_v2 is introduced requesting a fetch or a push will need to
be handled differently depending on the protocol version. Store the
protocol version the server is speaking in 'struct git_transport_data'
and use it to determine what to do in the case of a fetch or a push.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to prepare for the addition of protocol_v2 push the protocol
version discovery outside of 'get_remote_heads()'. This will allow for
keeping the logic for processing the reference advertisement for
protocol_v1 and protocol_v0 separate from the logic for protocol_v2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove code duplication and use the existing 'get_refs_via_connect()'
function to retrieve a remote's heads in 'fetch_refs_via_pack()' and
'git_transport_push()'.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert find_unique_abbrev and find_unique_abbrev_r to each take a
pointer to struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the declaration and definition of strbuf_add_unique_abbrev to
make it take a pointer to struct object_id. Predeclare the struct in
strbuf.h, as cache.h includes strbuf.h before it declares the struct,
and otherwise the struct declaration would have the wrong scope.
Apply the following semantic patch, along with the standard object_id
transforms, to adjust the callers:
@@
expression E1, E2, E3;
@@
- strbuf_add_unique_abbrev(E1, E2.hash, E3);
+ strbuf_add_unique_abbrev(E1, &E2, E3);
@@
expression E1, E2, E3;
@@
- strbuf_add_unique_abbrev(E1, E2->hash, E3);
+ strbuf_add_unique_abbrev(E1, E2, E3);
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The machinery to clone & fetch, which in turn involves packing and
unpacking objects, have been told how to omit certain objects using
the filtering mechanism introduced by the jh/object-filtering
topic, and also mark the resulting pack as a promisor pack to
tolerate missing objects, taking advantage of the mechanism
introduced by the jh/fsck-promisors topic.
* jh/partial-clone:
t5616: test bulk prefetch after partial fetch
fetch: inherit filter-spec from partial clone
t5616: end-to-end tests for partial clone
fetch-pack: restore save_commit_buffer after use
unpack-trees: batch fetching of missing blobs
clone: partial clone
partial-clone: define partial clone settings in config
fetch: support filters
fetch: refactor calculation of remote list
fetch-pack: test support excluding large blobs
fetch-pack: add --no-filter
fetch-pack, index-pack, transport: partial clone
upload-pack: add object filtering for partial clone
In preparation for implementing narrow/partial clone, the machinery
for checking object connectivity used by gc and fsck has been
taught that a missing object is OK when it is referenced by a
packfile specially marked as coming from trusted repository that
promises to make them available on-demand and lazily.
* jh/fsck-promisors:
gc: do not repack promisor packfiles
rev-list: support termination at promisor objects
sha1_file: support lazily fetching missing objects
introduce fetch-object: fetch one promisor object
index-pack: refactor writing of .keep files
fsck: support promisor objects as CLI argument
fsck: support referenced promisor objects
fsck: support refs pointing to promisor objects
fsck: introduce partialclone extension
extension.partialclone: introduce partial clone extension
Move the definition of the transport-specific functions provided by
transports, whether declared in transport.c or transport-helper.c, into
an internal header. This means that transport-using code (as opposed to
transport-declaring code) can no longer access these functions (without
importing the internal header themselves), making it clear that they
should use the transport_*() functions instead, and also allowing the
interface between the transport mechanism and an individual transport to
independently evolve.
This is superficially a reversal of commit 824d5776c3 ("Refactor
struct transport_ops inlined into struct transport", 2007-09-19).
However, the scope of the involved variables was neither affected nor
discussed in that commit, and I think that the advantages in making
those functions more private outweigh the advantages described in that
commit's commit message. A minor additional point is that the code has
gotten more complicated since then, in that the function-pointer
variables are potentially mutated twice (once initially and once if
transport_take_over() is invoked), increasing the value of corralling
them into their own struct.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After commit 0d0bac67ce ("transport: drop support for git-over-rsync",
2016-02-01), no transport in Git populates the "push" entry in the
transport vtable. Remove this entry.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce fetch-object, providing the ability to fetch one object from a
promisor remote.
This uses fetch-pack. To do this, the transport mechanism has been
updated with 2 flags, "from-promisor" to indicate that the resulting
pack comes from a promisor remote (and thus should be annotated as such
by index-pack), and "no-dependents" to indicate that only the objects
themselves need to be fetched (but fetching additional objects is
nevertheless safe).
Whenever "no-dependents" is used, fetch-pack will refrain from using any
object flags, because it is most likely invoked as part of a dynamic
object fetch by another Git command (which may itself use object flags).
An alternative to this is to leave fetch-pack alone, and instead update
the allocation of flags so that fetch-pack's flags never overlap with
any others, but this will end up shrinking the number of flags available
to nearly every other Git command (that is, every Git command that
accesses objects), so the approach in this commit was used instead.
This will be tested in a subsequent commit.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert update_ref, refs_update_ref, and write_pseudoref to use struct
object_id. Update the existing callers as well. Remove update_ref_oid,
as it is no longer needed.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This allows us to get rid of several write-only variables.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This allows us to get rid of some write-only variables, among them seven
SHA1 buffers.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A common pattern to free a piece of memory and assign NULL to the
pointer that used to point at it has been replaced with a new
FREE_AND_NULL() macro.
* ab/free-and-null:
*.[ch] refactoring: make use of the FREE_AND_NULL() macro
coccinelle: make use of the "expression" FREE_AND_NULL() rule
coccinelle: add a rule to make "expression" code use FREE_AND_NULL()
coccinelle: make use of the "type" FREE_AND_NULL() rule
coccinelle: add a rule to make "type" code use FREE_AND_NULL()
git-compat-util: add a FREE_AND_NULL() wrapper around free(ptr); ptr = NULL
Fix configuration codepath to pay proper attention to commondir
that is used in multi-worktree situation, and isolate config API
into its own header file.
* bw/config-h:
config: don't implicitly use gitdir or commondir
config: respect commondir
setup: teach discover_git_directory to respect the commondir
config: don't include config.h by default
config: remove git_config_iter
config: create config.h
Apply the result of the just-added coccinelle rule. This manually
excludes a few occurrences, mostly things that resulted in many
FREE_AND_NULL() on one line, that'll be manually fixed in a subsequent
change.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Stop including config.h by default in cache.h. Instead only include
config.h in those files which require use of the config system.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the bundle code, plus the sole external user of struct
ref_list_entry, to use struct object_id. Include cache.h from within
bundle.h to provide the definition. Convert some of the hash parsing
code to use parse_oid_hex to avoid needing to hard-code constant values.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git push --recurse-submodules --push-option=<string>" learned to
propagate the push option recursively down to pushes in submodules.
* bw/push-options-recursively-to-submodules:
push: propagate remote and refspec with --recurse-submodules
submodule--helper: add push-check subcommand
remote: expose parse_push_refspec function
push: propagate push-options with --recurse-submodules
push: unmark a local variable as static
Teach "push --recurse-submodules" to propagate, if given a name as remote, the
provided remote and refspec recursively to the pushes performed in the
submodules. The push will therefore only succeed if all submodules have a
remote with such a name configured.
Note that "push --recurse-submodules" with a path or URL as remote will not
propagate the remote or refspec and instead use the default remote and refspec
configured in the submodule, preserving the current behavior.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach push --recurse-submodules to propagate push-options recursively to
the pushes performed in the submodules.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since this structure handles an array of object IDs, rename it to struct
oid_array. Also rename the accessor functions and the initialization
constant.
This commit was produced mechanically by providing non-Documentation
files to the following Perl one-liners:
perl -pi -E 's/struct sha1_array/struct oid_array/g'
perl -pi -E 's/\bsha1_array_/oid_array_/g'
perl -pi -E 's/SHA1_ARRAY_INIT/OID_ARRAY_INIT/g'
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the callers to pass struct object_id by changing the function
declaration and definition and applying the following semantic patch:
@@
expression E1, E2;
@@
- sha1_array_append(E1, E2.hash)
+ sha1_array_append(E1, &E2)
@@
expression E1, E2;
@@
- sha1_array_append(E1, E2->hash)
+ sha1_array_append(E1, E2)
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since we will likely be introducing a new hash function at some point,
and that hash function might be longer than 40 hex characters, use the
constant GIT_MAX_HEXSZ, which is designed to be suitable for
allocations, instead of GIT_SHA1_HEXSZ. This will ease the transition
down the line by distinguishing between places where we need to allocate
memory suitable for the largest hash from those where we need to handle
the current hash.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git fetch" that requests a commit by object name, when the other
side does not allow such an request, failed without much
explanation.
* mm/fetch-show-error-message-on-unadvertised-object:
fetch-pack: add specific error for fetching an unadvertised object
fetch_refs_via_pack: call report_unmatched_refs
fetch-pack: move code to report unmatched refs to a function
"git fetch" currently doesn't bother to check that it got all refs it
sought, because the common case of requesting a nonexistent ref triggers
a die() in get_fetch_map. However, there's at least one case that
slipped through: "git fetch REMOTE SHA1" if the server doesn't allow
requests for unadvertised objects. Make fetch_refs_via_pack (which is
on the "git fetch" code path) call report_unmatched_refs so that we at
least get an error message in that case.
Signed-off-by: Matt McCutchen <matt@mattmccutchen.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git update-ref -d" and other operations to delete references did
not leave any entry in HEAD's reflog when the reference being
deleted was the current branch. This is not a problem in practice
because you do not want to delete the branch you are currently on,
but caused renaming of the current branch to something else not to
be logged in a useful way.
* km/delete-ref-reflog-message:
branch: record creation of renamed branch in HEAD's log
rename_ref: replace empty message in HEAD's log
update-ref: pass reflog message to delete_ref()
delete_ref: accept a reflog message argument
There are a few leaf functions in various files that call
resolve_refdup. Convert these functions to use struct object_id
internally to prepare for transitioning resolve_refdup itself.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the current branch is renamed with 'git branch -m/-M' or deleted
with 'git update-ref -m<msg> -d', the event is recorded in HEAD's log
with an empty message. In preparation for adding a more meaningful
message to HEAD's log in these cases, update delete_ref() to take a
message argument and pass it along to ref_transaction_delete().
Modify all callers to pass NULL for the new message argument; no
change in behavior is intended.
Note that this is relevant for HEAD's log but not for the deleted
ref's log, which is currently deleted along with the ref. Even if it
were not, an entry for the deletion wouldn't be present in the deleted
ref's log. files_transaction_commit() writes to the log if
REF_NEEDS_COMMIT or REF_LOG_ONLY are set, but lock_ref_for_update()
doesn't set REF_NEEDS_COMMIT for the deleted ref because REF_DELETING
is set. In contrast, the update for HEAD has REF_LOG_ONLY set by
split_head_update(), resulting in the deletion being logged.
Signed-off-by: Kyle Meyer <kyle@kyleam.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The current method for getting the refs from an alternate is
to run upload-pack in the alternate and parse its output
using the normal transport code. This works and is
reasonably short, but it has a very bad memory footprint
when there are a lot of refs in the alternate. There are two
problems:
1. It reads in all of the refs before passing any back to
us. Which means that our peak memory usage has to store
every ref (including duplicates for peeled variants),
even if our callback could determine that some are not
interesting (e.g., because they point to the same sha1
as another ref).
2. It allocates a "struct ref" for each one. Among other
things, this contains 3 separate 20-byte oids, along
with the name and various pointers. That can add up,
especially if the callback is only interested in the
sha1 (which it can store in a sha1_array as just 20
bytes).
On a particularly pathological case, where the alternate had
over 80 million refs pointing to only around 60,000 unique
objects, the peak heap usage of "git clone --reference" grew
to over 25GB.
This patch instead calls git-for-each-ref in the alternate
repository, and passes each line to the callback as we read
it. That drops the peak heap of the same command to 50MB.
I considered and rejected a few alternatives.
We could read all of the refs in the alternate using our own
ref code, just as we do with submodules. However, as memory
footprint is one of the concerns here, we want to avoid
loading those refs into our own memory as a whole.
It's possible that this will be a better technique in the
future when the ref code can more easily iterate without
loading all of packed-refs into memory.
Another option is to keep calling upload-pack, and just
parse its output ourselves in a streaming fashion. Besides
for-each-ref being simpler (we get to define the format
ourselves, and don't have to deal with speaking the git
protocol), it's more flexible for possible future changes.
For instance, it might be useful for the caller to be able
to limit the set of "interesting" alternate refs. The
motivating example is one where many "forks" of a particular
repository share object storage, and the shared storage has
refs for each fork (which is why so many of the refs are
duplicates; each fork has the same tags). A plausible
future optimization would be to ask for the alternate refs
for just _one_ fork (if you had some out-of-band way of
knowing which was the most interesting or important for the
current operation).
Similarly, no callbacks actually care about the symref value
of alternate refs, and as before, this patch ignores them
entirely. However, if we wanted to add them, for-each-ref's
"%(symref)" is going to be more flexible than upload-pack,
because the latter only handles the HEAD symref due to
historical constraints.
There is one potential downside, though: unlike upload-pack,
our for-each-ref command doesn't report the peeled value of
refs. The existing code calls the alternate_ref_fn callback
twice for tags: once for the tag, and once for the peeled
value with the refname set to "ref^{}".
For the callers in fetch-pack, this doesn't matter at all.
We immediately peel each tag down to a commit either way (so
there's a slight improvement, as do not bother passing the
redundant data over the pipe). For the caller in
receive-pack, it means we will not advertise the peeled
values of tags in our alternate. However, we also don't
advertise peeled values for our _own_ tags, so this is
actually making things more consistent.
It's unclear whether receive-pack advertising peeled values
is a win or not. On one hand, giving more information to the
other side may let it omit some objects from the push. On
the other hand, for tags which both sides have, they simply
bloat the advertisement. The upload-pack advertisement of
git.git is about 30% larger than the receive-pack
advertisement due to its peeled information.
This patch omits the peeled information from
for_each_alternate_ref entirely, and leaves it up to the
caller whether they want to dig up the information.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Breaking down the fields in the interface makes it easier to
change the backend of for_each_alternate_ref to something
that doesn't use "struct ref" internally.
The only field that callers actually look at is the oid,
anyway. The refname is kept in the interface as a plausible
thing for future code to want.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have a string with ".../objects" pointing to the
alternate object store, and overwrite bits of it to look at
other paths in the (potential) git repository holding it.
This works because the only path we care about is "refs",
which is shorter than "objects".
Using a strbuf to hold the path lets us get rid of some
magic numbers, and makes it more obvious that the memory
operations are safe.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The real_pathdup() function will have removed extra slashes
for us already (on top of the normalize_path() done when we
created the alternate_object_database struct in the first
place).
Incidentally, this also fixes the case where the path is
just "/", which would read off the start of the array.
That doesn't seem possible to trigger in practice, though,
as link_alt_odb_entry() blindly eats trailing slashes,
including a bare "/".
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In older versions of git, if real_path() failed to resolve
the alternate object store path, we would die() with an
error. However, since 4ac9006f8 (real_path: have callers use
real_pathdup and strbuf_realpath, 2016-12-12) we use the
real_pathdup() function, which may return NULL. Since we
don't check the return value, we can segfault.
This is hard to trigger in practice, since we check that the
path is accessible before creating the alternate_object_database
struct. But it could be removed racily, or we could see a
transient filesystem error.
We could restore the original behavior by switching back to
xstrdup(real_path()). However, dying is probably not the
best option here. This whole function is best-effort
already; there might not even be a repository around the
shared objects at all. And if the alternate store has gone
away, there are no objects to show.
So let's just quietly return, as we would if we failed to
open "refs/", or if upload-pack failed to start, etc.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
