Commit Graph

44563 Commits

Author SHA1 Message Date
Junio C Hamano
faacc8efe5 Merge branch 'jk/common-main' into maint
There are certain house-keeping tasks that need to be performed at
the very beginning of any Git program, and programs that are not
built-in commands had to do them exactly the same way as "git"
potty does.  It was easy to make mistakes in one-off standalone
programs (like test helpers).  A common "main()" function that
calls cmd_main() of individual program has been introduced to
make it harder to make mistakes.

* jk/common-main:
  mingw: declare main()'s argv as const
  common-main: call git_setup_gettext()
  common-main: call restore_sigpipe_to_default()
  common-main: call sanitize_stdfds()
  common-main: call git_extract_argv0_path()
  add an extra level of indirection to main()
2016-09-08 21:35:51 -07:00
Stefan Beller
ca9b37e5a8 diff: remove dead code
When `len < 1`, len has to be 0 or negative, emit_line will then remove the
first character and by then `len` would be negative. As this doesn't
happen, it is safe to assume it is dead code.

This continues to simplify the code, which was started in b8d9c1a66b
(2009-09-03,  diff.c: the builtin_diff() deals with only two-file
comparison).

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-08 13:54:37 -07:00
Stefan Beller
ba16233ccd diff: omit found pointer from emit_callback
We keep the actual data in the diff options, which are just as accessible.
Remove the pointer stored in struct emit_callback for readability.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-08 13:54:23 -07:00
Stefan Beller
fb33b62ca6 diff.c: use diff_options directly
The value of `ecbdata->opt` is accessible via the short variable `o`
already, so let's use that instead.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-08 13:46:46 -07:00
Stefan Beller
5cb5fe4ae0 transport: report missing submodule pushes consistently on stderr
The surrounding advice is printed to stderr, but the list of submodules
is not. Make the report consistent by reporting everything to stderr.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-08 13:28:15 -07:00
Nguyễn Thái Ngọc Duy
7f82b24e30 checkout: add some spaces between code and comment
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-08 12:55:51 -07:00
Alex Henrie
a1c8044662 unpack-trees: do not capitalize "working"
In English, only proper nouns are capitalized.

Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-08 12:17:23 -07:00
Alex Henrie
1c67d534d9 git-merge-octopus: do not capitalize "octopus"
In English, only proper nouns are capitalized.

Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-08 12:17:10 -07:00
Alex Henrie
7c406bd8a7 git-rebase--interactive: fix English grammar
Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-08 12:17:03 -07:00
Alex Henrie
88c782942c cat-file: put spaces around pipes in usage string
This makes the style a little more consistent with other usage strings,
and will resolve a warning at
https://www.softcatala.org/recursos/quality/git.html

Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-08 12:16:38 -07:00
Alex Henrie
d65fdc9c5d am: put spaces around pipe in usage string
This makes the style a little more consistent with other usage strings,
and will resolve a warning at
https://www.softcatala.org/recursos/quality/git.html

Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-08 12:13:28 -07:00
Jeff King
d63ed6ef24 remote-curl: handle URLs without protocol
Generally remote-curl would never see a URL that did not
have "proto:" at the beginning, as that is what tells git to
run the "git-remote-proto" helper (and git-remote-http, etc,
are aliases for git-remote-curl).

However, the special syntax "proto::something" will run
git-remote-proto with only "something" as the URL. So a
malformed URL like:

  http::/example.com/repo.git

will feed the URL "/example.com/repo.git" to
git-remote-http. The resulting URL has no protocol, but the
code added by 372370f (http: use credential API to handle
proxy authentication, 2016-01-26) does not handle this case
and segfaults.

For the purposes of this code, we don't really care what the
exact protocol; only whether or not it is https. So let's
just assume that a missing protocol is not, and curl will
handle the real error (which is that the URL is nonsense).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-08 11:23:43 -07:00
brian m. carlson
3a5d7c55f7 builtin/reset: convert to use struct object_id
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:43 -07:00
brian m. carlson
031cee5b73 builtin/commit-tree: convert to struct object_id
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:43 -07:00
brian m. carlson
8c88769ba4 builtin/am: convert to struct object_id
Convert uses of unsigned char [20] to struct object_id.  Rename the
generically-named "ptr" to "old_oid" and make it const.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:43 -07:00
brian m. carlson
8f6dc7e32e refs: add an update_ref_oid function.
Several places around the codebase want to pass update_ref data from
struct object_id, but update_ref may also be passed NULL pointers.
Instead of checking and dereferencing in every caller, create an
update_ref_oid which wraps update_ref and provides this functionality.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:43 -07:00
brian m. carlson
151b2911c1 sha1_name: convert get_sha1_mb to struct object_id
All of the callers of this function use struct object_id, so rename it
to get_oid_mb and make it take struct object_id instead of
unsigned char *.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:43 -07:00
brian m. carlson
71445a0fef builtin/update-index: convert file to struct object_id
Convert all functions to use struct object_id, and replace instances of
hardcoded 40, 41, and 42 with appropriate references to GIT_SHA1_HEXSZ.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:43 -07:00
brian m. carlson
13ac141038 notes: convert init_notes to use struct object_id
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson
8ec46d7e3e builtin/rm: convert to use struct object_id
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson
110d26fce8 builtin/blame: convert file to use struct object_id
Convert this file to use struct object_id, and additionally convert some
uses of the constant 40 to GIT_SHA1_HEXSZ.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson
d449347d08 Convert read_mmblob to take struct object_id.
Since all of its callers have been updated, convert read_mmblob to 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>
2016-09-07 12:59:42 -07:00
brian m. carlson
e910bb1e79 notes-merge: convert struct notes_merge_pair to struct object_id
Convert each of this structure's members from an unsigned char array to
a struct object_id.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson
60af7691db builtin/checkout: convert some static functions to struct object_id
Convert all the static functions that are not callbacks to struct
object_id.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson
7eda0e4fbb streaming: make stream_blob_to_fd take struct object_id
Since all of its callers have been updated, modify stream_blob_to_fd to
take a struct object_id.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson
acad70d106 builtin: convert textconv_object to use struct object_id
Since all of its callers have been updated, make textconv_object take a
struct object_id.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson
63ecb99e0d builtin/cat-file: convert some static functions to struct object_id
Convert all of the static functions that are not callbacks to use struct
object_id.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson
cd4f77beb7 builtin/cat-file: convert struct expand_data to use struct object_id
Convert struct cache_entry to use struct object_id by applying the
following semantic patch and the object_id transforms from contrib,
plus the actual change to the struct:

@@
struct expand_data E1;
@@
- E1.sha1
+ E1.oid.hash

@@
struct expand_data *E1;
@@
- E1->sha1
+ E1->oid.hash

@@
struct expand_data E1;
@@
- E1.delta_base_sha1
+ E1.delta_base_oid.hash

@@
struct expand_data *E1;
@@
- E1->delta_base_sha1
+ E1->delta_base_oid.hash

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson
d801627b0c builtin/log: convert some static functions to use struct object_id
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson
a7bcfa126b builtin/blame: convert struct origin to use struct object_id
Convert struct origin to use struct object_id by applying the
following semantic patch and the object_id transforms from contrib,
plus the actual change to the struct:

@@
struct origin E1;
@@
- E1.blob_sha1
+ E1.blob_oid.hash

@@
struct origin *E1;
@@
- E1->blob_sha1
+ E1->blob_oid.hash

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson
eb1c9c7328 builtin/apply: convert static functions to struct object_id
There were several static functions using unsigned char arrays for SHA-1
values.  Convert them to use struct object_id.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson
99d1a9861a cache: convert struct cache_entry to use struct object_id
Convert struct cache_entry to use struct object_id by applying the
following semantic patch and the object_id transforms from contrib, plus
the actual change to the struct:

@@
struct cache_entry E1;
@@
- E1.sha1
+ E1.oid.hash

@@
struct cache_entry *E1;
@@
- E1->sha1
+ E1->oid.hash

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
Christian Couder
edfac5ebff builtin/am: use apply API in run_apply()
This replaces run_apply() implementation with a new one that
uses the apply API that has been previously prepared in
apply.c and apply.h.

This shoud improve performance a lot in certain cases.

As the previous implementation was creating a new `git apply`
process to apply each patch, it could be slow on systems like
Windows where it is costly to create new processes.

Also the new `git apply` process had to read the index from
disk, and when the process was done the calling process
discarded its own index and read back from disk the new
index that had been created by the `git apply` process.

This could be very inefficient with big repositories that
have big index files, especially when the system decided
that it was a good idea to run the `git apply` processes on
a different processor core.

Also eliminating index reads enables further performance
improvements by using:

`git update-index --split-index`

For example here is a benchmark of a multi hundred commit
rebase on the Linux kernel on a Debian laptop with SSD:

command: git rebase --onto 1993b17 52bef0c 29dde7c

Vanilla "next" without split index:                1m54.953s
Vanilla "next" with split index:                   1m22.476s
This series on top of "next" without split index:  1m12.034s
This series on top of "next" with split index:     0m15.678s

(using branch "next" from mid April 2016.)

Benchmarked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:54 -07:00
Christian Couder
5b0b57fd91 apply: learn to use a different index file
Sometimes we want to apply in a different index file.

Before the apply functionality was libified it was possible to
use the GIT_INDEX_FILE environment variable, for this purpose.

But now, as the apply functionality has been libified, it should
be possible to do that in a libified way.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:54 -07:00
Christian Couder
b4290342dd apply: pass apply state to build_fake_ancestor()
To libify git apply functionality, we will need to read from a
different index file in get_current_sha1(). This index file will be
stored in "struct apply_state", so let's pass the state to
build_fake_ancestor() which will later pass it to get_current_sha1().

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:54 -07:00
Christian Couder
7e1bad24e3 apply: refactor git apply option parsing
Parsing `git apply` options can be useful to other commands that
want to call the libified apply functionality, because this way
they can easily pass some options from their own command line to
the libified apply functionality.

This will be used by `git am` in a following patch.

To make this possible, let's refactor the `git apply` option
parsing code into a new libified apply_parse_options() function.

Doing that makes it possible to remove some functions definitions
from "apply.h" and make them static in "apply.c".

Helped-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Christian Couder
45b78d8ba3 apply: change error_routine when silent
To avoid printing anything when applying with
`state->apply_verbosity == verbosity_silent`, let's save the
existing warn and error routines before applying, and let's
replace them with a routine that does nothing.

Then after applying, let's restore the saved routines.

Note that, as we need to restore the saved routines in all
cases, we cannot return early any more in apply_all_patches().

Helped-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Christian Couder
725149beab usage: add get_error_routine() and get_warn_routine()
Let's make it possible to get the current error_routine and warn_routine,
so that we can store them before using set_error_routine() or
set_warn_routine() to use new ones.

This way we will be able put back the original routines, when we are done
with using new ones.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Christian Couder
b83f108b08 usage: add set_warn_routine()
There are already set_die_routine() and set_error_routine(),
so let's add set_warn_routine() as this will be needed in a
following commit.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Christian Couder
487beee0c3 apply: don't print on stdout in verbosity_silent mode
When apply_verbosity is set to verbosity_silent nothing should be
printed on both stderr and stdout.

To avoid printing on stdout, we can just skip calling the following
functions:

	- stat_patch_list(),
	- numstat_patch_list(),
	- summary_patch_list().

It is safe to do that because the above functions have no side
effects other than printing:

- stat_patch_list() only computes some local values and then call
show_stats() and print_stat_summary(), those two functions only
compute local values and call printing functions,
- numstat_patch_list() also only computes local values and calls
printing functions,
- summary_patch_list() calls show_file_mode_name(), printf(),
show_rename_copy(), show_mode_change() that are only printing.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Christian Couder
a46160d27e apply: make it possible to silently apply
This changes 'int apply_verbosely' into 'enum apply_verbosity', and
changes the possible values of the variable from a bool to
a tristate.

The previous 'false' state is changed into 'verbosity_normal'.
The previous 'true' state is changed into 'verbosity_verbose'.

The new added state is 'verbosity_silent'. It should prevent
anything to be printed on both stderr and stdout.

This is needed because `git am` wants to first call apply
functionality silently, if it can then fall back on 3-way merge
in case of error.

Printing on stdout, and calls to warning() or error() are not
taken care of in this patch, as that will be done in following
patches.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Christian Couder
90875eca5a apply: use error_errno() where possible
To avoid possible mistakes and to uniformly show the errno
related messages, let's use error_errno() where possible.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Christian Couder
9123d5ddfe apply: make some parsing functions static again
Some parsing functions that were used in both "apply.c" and
"builtin/apply.c" are now only used in the former, so they
can be made static to "apply.c".

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Christian Couder
13b5af22f3 apply: move libified code from builtin/apply.c to apply.{c,h}
As most of the apply code in builtin/apply.c has been libified by a number of
previous commits, it can now be moved to apply.{c,h}, so that more code can
use it.

Helped-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Helped-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Christian Couder
803bf4e012 apply: rename and move opt constants to apply.h
The constants for the "inaccurate-eof" and the "recount" options will
be used in both "apply.c" and "builtin/apply.c", so they need to go
into "apply.h", and therefore they need a name that is more specific
to the API they belong to.

Helped-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Christian Couder
da8e30dcd9 builtin/apply: rename option parsing functions
As these functions are going to be part of the libified
apply API, let's give them a name that is more specific
to the apply API.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Christian Couder
603752a88d builtin/apply: make create_one_file() return -1 on error
To libify `git apply` functionality we have to signal errors to the
caller instead of exit()ing.

To do that in a compatible manner with the rest of the error handling
in "builtin/apply.c", create_one_file() should return -1 instead of
calling exit().

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Christian Couder
739d8a16b5 builtin/apply: make try_create_file() return -1 on error
To libify `git apply` functionality we have to signal errors to the
caller instead of die()ing.

To do that in a compatible manner with the rest of the error handling
in "builtin/apply.c", try_create_file() should return -1 in case of
error.

Unfortunately try_create_file() currently returns -1 to signal a
recoverable error. To fix that, let's make it return 1 in case of
a recoverable error and -1 in case of an unrecoverable error.

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:29:53 -07:00
Ralf Thielow
37875b4733 rebase -i: improve advice on bad instruction lines
If we found bad instruction lines in the instruction sheet
of interactive rebase, we give the user advice on how to
fix it.  However, we don't tell the user what to do afterwards.
Give the user advice to run 'git rebase --continue' after
the fix.

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 11:56:05 -07:00
Jeff King
b773ddea2c pack-objects: walk tag chains for --include-tag
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>
2016-09-07 11:45:31 -07:00