Commit Graph

60723 Commits

Author SHA1 Message Date
Jeff King
218389b9f3 p5302: count up to online-cpus for thread tests
When PERF_EXTRA is enabled, p5302 checks the performance of index-pack
with various numbers of threads. This can be useful for deciding what
the default should be (which is currently capped at 3 threads based on
the results of this script).

However, we only go up to 8 threads, and modern machines may have more.
Let's get the number of CPUs from test-tool, and test various numbers of
threads between one and that maximum.

Note that the current tests aren't all identical, as we have to set
GIT_FORCE_THREADS for the --threads=1 test (which measures the overhead
of starting a single worker thread versus the "0" case of using the main
thread). To keep the loop simple, we'll keep the "0" case out of it, and
set GIT_FORCE_THREADS=1 for all of the other cases (it's a noop for all
but the "1" case, since numbers higher than 1 would always need
threads).

Note also that we could skip running "test-tool" if PERF_EXTRA isn't
set. However, there's some small value in knowing the number of threads,
so that we can mark each test as skipped in the output.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 12:02:36 -07:00
Jeff King
47274251a4 p5302: disable thread-count parameter tests by default
The primary function of the perf suite is to detect regressions (or
improvements) between versions of Git. The only numbers we show a direct
comparison for are timings between the same test run on two different
versions.

However, it can sometimes be used to collect other information.  For
instance, p5302 runs the same index-pack operation with different thread
counts. The output doesn't directly compare these, but anybody
interested in working on index-pack can manually compare the results.

For a normal regression run of the full perf-suite, though, this incurs
a significant cost to generate numbers nobody will actually look at;
about 25% of the total time of the test suite is spent in p5302. And the
low-thread-count runs are the most expensive part of it, since they're
(unsurprisingly) not using as many threads.

Let's skip these tests by default, but make it possible for people
working on index-pack to still run them by setting an environment
variable. Rather than make this specific to p5302, let's introduce a
generic mechanism. This makes it possible to run the full suite with
every possible test if somebody really wants to burn some CPU.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 12:02:36 -07:00
Shourya Shukla
2a0d1a5ce2 t7401: add a NEEDSWORK
Add a NEEDSWORK regarding the outdated syntax and working of the test,
which may need to be improved to obtain better and desired results.

While at it, change the word 'test' to 'test script' in the test
description to avoid ambiguity.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Helped-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Shourya Shukla <shouryashukla.oo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 11:47:56 -07:00
Shourya Shukla
3a4fdeee89 t7401: change indentation for enhanced readability
Change the indentation of expected outputs for enhanced readability of
the tests. Also modify the heredoc string limiter in a test which lacks
it to support the indentation change.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Taylor Blau <me@taylorr.com>
Signed-off-by: Shourya Shukla <shouryashukla.oo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 11:47:56 -07:00
Shourya Shukla
17c102e30d t7401: change syntax of test_i18ncmp calls for clarity
Change the test_i18ncmp syntax from 'test_i18ncmp actual expected' to
'test_i18ncmp expected actual' to align it with the convention followed
by other tests in the test script.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Signed-off-by: Shourya Shukla <shouryashukla.oo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 11:47:55 -07:00
Shourya Shukla
7303da3002 t7401: use 'short' instead of 'verify' and cut in rev-parse calls
'git rev-parse' can limit the number of characters in the hash it
outputs using the '--short' option, thereby, making the 'cut' invocation
redundant. Since using '--short' implies '--verify' as well, we can
safely replace the latter with the former. This change results in the
helper functions getting the hash in the same way 'summary' gets the
hash internally.

So, avoid the unnecessary invocation to 'cut' in the helper
functions.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Signed-off-by: Shourya Shukla <shouryashukla.oo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 11:47:55 -07:00
Shourya Shukla
94e06c9057 t7401: modernize style
The tests in 't7401-submodule-summary.sh' were written a long time ago
and has a violation with respect to our CodingGuidelines which is,
incorrect spacing in usages of the redirection operator.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Helped-by: Denton Liu <liu.denton@gmail.com>
Helped-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Shourya Shukla <shouryashukla.oo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 11:47:55 -07:00
Han-Wen Nienhuys
b8825ef233 sequencer: treat REVERT_HEAD as a pseudo ref
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 11:20:11 -07:00
Han-Wen Nienhuys
b6d2558c9e builtin/commit: suggest update-ref for pseudoref removal
When pseudorefs move to a different ref storage mechanism, pseudorefs no longer
can be removed with 'rm'. Instead, suggest a "update-ref -d" command, which will
work regardless of ref storage backend.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 11:20:10 -07:00
Han-Wen Nienhuys
c8e4159efd sequencer: treat CHERRY_PICK_HEAD as a pseudo ref
Check for existence and delete CHERRY_PICK_HEAD through ref functions.
This will help cherry-pick work with alternate ref storage backends.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 11:20:10 -07:00
Han-Wen Nienhuys
3f9f1acccf refs: make refs_ref_exists public
This will be necessary to replace file existence checks for pseudorefs.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21 11:20:10 -07:00
Raymond E. Pasco
d064702be3 git-apply.txt: update descriptions of --cached, --index
The blurb for "--cached" says it implies "--index", but in reality
"--cached" and "--index" are distinct modes with different behavior.

Additionally, the descriptions of "--index" and "--cached" are somewhat
unclear about what might be modified, and what "--index" looks for to
determine that the index and working copy "match".

Rewrite the blurbs for both options for clarity and accuracy.

Signed-off-by: Raymond E. Pasco <ray@ameretat.dev>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-20 16:34:37 -07:00
Jonathan Tan
1b03df5f1e fetch-pack: in partial clone, pass --promisor
When fetching a pack from a promisor remote, the corresponding .promisor
file needs to be created. "fetch-pack" originally did this by passing
"--promisor" to "index-pack", but in 5374a290aa ("fetch-pack: write
fetched refs to .promisor", 2019-10-16), "fetch-pack" was taught to do
this itself instead, because it needed to store ref information in the
.promisor file.

This causes a problem with superprojects when transfer.fsckobjects is
set, because in the current implementation, it is "index-pack" that
calls fsck_finish() to check the objects; before 5374a290aa,
fsck_finish() would see that .gitmodules is a promisor object and
tolerate it being missing, but after, there is no .promisor file (at the
time of the invocation of fsck_finish() by "index-pack") to tell it that
.gitmodules is a promisor object, so it returns an error.

Therefore, teach "fetch-pack" to pass "--promisor" to index pack once
again. "fetch-pack" will subsequently overwrite this file with the ref
information.

An alternative is to instead move object checking to "fetch-pack", and
let "index-pack" only index the files. However, since "index-pack" has
to inflate objects in order to index them, it seems reasonable to also
let it check the objects (which also require inflated files).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-20 13:18:27 -07:00
Matthew Rogers
1cf3d5db9b diff: teach --stat to ignore uninteresting modifications
When options such as --ignore-space-change are in use, files with
modifications can have no interesting textual changes worth showing.  In
such cases, "git diff --stat" shows 0 lines of additions and deletions.
Teach "git diff --stat" not to show such a path in its output, which
would be more natural.

However, we don't want to prevent the display  of all files that have 0
effective diffs since they could be the result of a rename, permission
change, or other similar operation that may still be of interest so we
special case additions and deletions as they are always interesting.

Signed-off-by: Matthew Rogers <mattr94@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-19 17:53:32 -07:00
Ryan Zoeller
c099f579b9 completion: add GIT_COMPLETION_SHOW_ALL env var
When set to 1, GIT_COMPLETION_SHOW_ALL causes --git-completion-helper-all
to be passed instead of --git-completion-helper.

Signed-off-by: Ryan Zoeller <rtzoeller@rtzoeller.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-19 17:46:17 -07:00
Ryan Zoeller
a0abe5e3b7 parse-options: add --git-completion-helper-all
--git-completion-helper excludes hidden options, such as --allow-empty
for git commit. This is typically helpful, but occasionally we want
auto-completion for obscure flags. --git-completion-helper-all returns
all options, even if they are marked as hidden or nocomplete.

Signed-off-by: Ryan Zoeller <rtzoeller@rtzoeller.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-19 17:46:17 -07:00
Junio C Hamano
675a4aaf3b Ninth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-19 16:14:53 -07:00
Junio C Hamano
5a0482662f Merge branch 'jh/mingw-unlink'
"unlink" emulation on MinGW has been optimized.

* jh/mingw-unlink:
  mingw: improve performance of mingw_unlink()
2020-08-19 16:14:53 -07:00
Junio C Hamano
6f8a2138b9 Merge branch 'ds/sha256-leftover-bits'
midx and commit-graph files now use the byte defined in their file
format specification for identifying the hash function used for
object names.

* ds/sha256-leftover-bits:
  multi-pack-index: use hash version byte
  commit-graph: use the "hash version" byte
  t/README: document GIT_TEST_DEFAULT_HASH
2020-08-19 16:14:53 -07:00
Junio C Hamano
74a395c484 Merge branch 'ma/sha-256-docs'
Further update of docs to adjust to the recent SHA-256 work.

* ma/sha-256-docs:
  shallow.txt: document SHA-256 shallow format
  protocol-capabilities.txt: clarify "allow-x-sha1-in-want" re SHA-256
  index-format.txt: document SHA-256 index format
  http-protocol.txt: document SHA-256 "want"/"have" format
2020-08-19 16:14:52 -07:00
Junio C Hamano
2a978f8273 Merge branch 'jc/object-names-are-not-sha-1'
A few end-user facing messages have been updated to be
hash-algorithm agnostic.

* jc/object-names-are-not-sha-1:
  messages: avoid SHA-1 in end-user facing messages
2020-08-19 16:14:52 -07:00
Junio C Hamano
336fbd18bb Merge branch 'bc/sha-256-doc-updates'
Further update of docs to adjust to the recent SHA-256 work.

* bc/sha-256-doc-updates:
  docs: fix step in transition plan
  docs: document SHA-256 pack and indices
2020-08-19 16:14:51 -07:00
Junio C Hamano
ee356a8818 Merge branch 'pb/set-url-docfix'
Doc fix.

* pb/set-url-docfix:
  fetch, pull doc: correct description of '--set-upstream'
2020-08-19 16:14:51 -07:00
Junio C Hamano
b350c4debe Merge branch 'pb/userdiff-fortran-update'
The regexp to identify the function boundary for FORTRAN programs
has been updated.

* pb/userdiff-fortran-update:
  userdiff: improve Fortran xfuncname regex
  userdiff: add tests for Fortran xfuncname regex
2020-08-19 16:14:50 -07:00
Junio C Hamano
ecc796caa2 Merge branch 'jb/commit-graph-doc-fix'
Docfix.

* jb/commit-graph-doc-fix:
  docs: commit-graph: fix some whitespace in the diagram
2020-08-19 16:14:49 -07:00
Junio C Hamano
93121dfd8c Merge branch 'jk/blame-coalesce-fix'
When given more than one target line ranges, "git blame -La,b
-Lc,d" was over-eager to coalesce groups of original lines and
showed incorrect results, which has been corrected.

* jk/blame-coalesce-fix:
  blame: only coalesce lines that are adjacent in result
  t8003: factor setup out of coalesce test
  t8003: check output of coalesced blame
2020-08-19 16:14:49 -07:00
Junio C Hamano
4499a42d0c Merge branch 'ak/sequencer-fix-find-uniq-abbrev'
Ring buffer with size 4 used for bin-hex translation resulted in a
wrong object name in the sequencer's todo output, which has been
corrected.

* ak/sequencer-fix-find-uniq-abbrev:
  rebase -i: fix possibly wrong onto hash in todo
2020-08-19 16:14:48 -07:00
Junio C Hamano
6cceea19eb Merge branch 'en/sequencer-merge-labels'
The commit labels used to explain each side of conflicted hunks
placed by the sequencer machinery have been made more readable by
humans.

* en/sequencer-merge-labels:
  sequencer: avoid garbled merge machinery messages due to commit labels
2020-08-19 16:14:47 -07:00
Junio C Hamano
9cdf86b2ee Merge branch 'rs/preserve-merges-unused-code-removal'
Code clean-up.

* rs/preserve-merges-unused-code-removal:
  rebase: remove unused function reschedule_last_action
2020-08-19 16:14:46 -07:00
Junio C Hamano
f577d305c7 Merge branch 'rs/upload-pack-sigchain-fix'
Code clean-up.

* rs/upload-pack-sigchain-fix:
  upload-pack: remove superfluous sigchain_pop() call
2020-08-19 16:14:45 -07:00
Junio C Hamano
b10a44e6b6 Merge branch 'rp/ita-diff-modefix'
"git diff [<tree-ish>] $path" for a $path that is marked with i-t-a
bit was not showing the mode bits from the working tree.

* rp/ita-diff-modefix:
  diff-lib: use worktree mode in diffs from i-t-a entries
2020-08-19 16:14:44 -07:00
Junio C Hamano
36d225c7d4 Merge branch 'en/merge-tests'
Updates to "git merge" tests, in preparation for a new merge
strategy backend.

* en/merge-tests:
  t6425: be more flexible with rename/delete conflict messages
  t642[23]: be more flexible for add/add conflicts involving pair renames
  t6422, t6426: be more flexible for add/add conflicts involving renames
  t6423: add an explanation about why one of the tests does not pass
  t6416, t6423: clarify some comments and fix some typos
  t6422: fix multiple errors with the mod6 test expectations
  t6423: fix test setup for a couple tests
  t6416, t6422: fix incorrect untracked file count
  t6422: fix bad check against missing file
  t6418: tighten delete/normalize conflict testcase
  Collect merge-related tests to t64xx
2020-08-19 16:14:43 -07:00
Rohit Ashiwal
27126692ba rebase: add --reset-author-date
The previous commit introduced --ignore-date flag to rebase -i, but the
name is rather vague as it does not say whether the author date or the
committer date is ignored. Add an alias to convey the precise purpose.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-19 15:22:56 -07:00
Phillip Wood
a3894aad67 rebase -i: support --ignore-date
Rebase is implemented with two different backends - 'apply' and
'merge' each of which support a different set of options. In
particular the apply backend supports a number of options implemented
by 'git am' that are not implemented in the merge backend. This means
that the available options are different depending on which backend is
used which is confusing. This patch adds support for the --ignore-date
option to the merge backend. This option uses the current time as the
author date rather than reusing the original author date when
rewriting commits. We take care to handle the combination of
--ignore-date and --committer-date-is-author-date in the same way as
the apply backend.

Original-patch-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-19 15:19:59 -07:00
Han-Wen Nienhuys
e811530278 refs: read FETCH_HEAD and MERGE_HEAD generically
The FETCH_HEAD and MERGE_HEAD refs must be stored in a file, regardless of the
type of ref backend. This is because they can hold more than just a single ref.

To accomodate them for alternate ref backends, read them from a file generically
in refs_read_raw_ref()

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-19 14:08:04 -07:00
Han-Wen Nienhuys
5085aef4c8 refs: move gitdir into base ref_store
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-19 14:08:04 -07:00
Han-Wen Nienhuys
4877c6c738 refs: fix comment about submodule ref_stores
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-19 14:08:03 -07:00
Han-Wen Nienhuys
e39620f07e refs: split off reading loose ref data in separate function
This prepares for handling FETCH_HEAD (which is not a regular ref)
separately from the ref backend.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-19 14:08:03 -07:00
Elijah Newren
eceba53214 dir: fix problematic API to avoid memory leaks
The dir structure seemed to have a number of leaks and problems around
it.  First I noticed that parent_hashmap and recursive_hashmap were
being leaked (though Peff noticed and submitted fixes before me).  Then
I noticed in the previous commit that clear_directory() was only taking
responsibility for a subset of fields within dir_struct, despite the
fact that entries[] and ignored[] we allocated internally to dir.c.
That, of course, resulted in many callers either leaking or haphazardly
trying to free these arrays and their contents.

Digging further, I found that despite the pretty clear documentation
near the top of dir.h that folks were supposed to call clear_directory()
when the user no longer needed the dir_struct, there were four callers
that didn't bother doing that at all.  However, two of them clearly
thought about leaks since they had an UNLEAK(dir) directive, which to me
suggests that the method to free the data was too unclear.  I suspect
the non-obviousness of the API and its holes led folks to avoid it,
which then snowballed into further problems with the entries[],
ignored[], parent_hashmap, and recursive_hashmap problems.

Rename clear_directory() to dir_clear() to be more in line with other
data structures in git, and introduce a dir_init() to handle the
suggested memsetting of dir_struct to all zeroes.  I hope that a name
like "dir_clear()" is more clear, and that the presence of dir_init()
will provide a hint to those looking at the code that they need to look
for either a dir_clear() or a dir_free() and lead them to find
dir_clear().

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 17:17:31 -07:00
Elijah Newren
dad4f23ce5 dir: make clear_directory() free all relevant memory
The calling convention for the dir API is supposed to end with a call to
clear_directory() to free up no longer needed memory.  However,
clear_directory() didn't free dir->entries or dir->ignored.  I believe
this was an oversight, but a number of callers noticed memory leaks and
started free'ing these.  Unfortunately, they did so somewhat haphazardly
(sometimes freeing the entries in the arrays, and sometimes only
free'ing the arrays themselves).  This suggests the callers weren't
trying to make sure any possible memory used might be free'd, but just
the memory they noticed their usecase definitely had allocated.

Fix this mess by moving all the duplicated free'ing logic into
clear_directory().  End by resetting dir to a pristine state so it could
be reused if desired.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 17:17:29 -07:00
Jonathan Tan
9dfa8dbeee fetch-pack: remove no_dependents code
Now that Git has switched to using a subprocess to lazy-fetch missing
objects, remove the no_dependents code as it is no longer used.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 16:46:53 -07:00
Jonathan Tan
7ca3c0ac37 promisor-remote: lazy-fetch objects in subprocess
Teach Git to lazy-fetch missing objects in a subprocess instead of doing
it in-process. This allows any fatal errors that occur during the fetch
to be isolated and converted into an error return value, instead of
causing the current command being run to terminate.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 16:46:53 -07:00
René Scharfe
82a62015a7 patch-id: ignore newline at end of file in diff_flush_patch_id()
Whitespace is ignored when calculating patch IDs.  This is done by
removing all whitespace from diff lines before hashing them, including
a newline at the end of a file.  If that newline is missing, however,
diff reports that fact in a separate line containing "\ No newline at
end of file\n", and this marker is hashed like a context line.

This goes against our goal of making patch IDs independent of
whitespace.  Use the same heuristic that 2485eab55c (git-patch-id: do
not trip over "no newline" markers, 2011-02-17) added to git patch-id
instead and skip diff lines that start with a backslash and a space
and are longer than twelve characters.

Reported-by: Tilman Vogel <tilman.vogel@web.de>
Initial-test-by: Tilman Vogel <tilman.vogel@web.de>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 16:14:01 -07:00
Matheus Tavares
748f733d54 checkout_entry(): remove unreachable error() call
This if statement never evaluates to true since we already check
state->force a few lines above, and immediately return when it is
false.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 13:26:10 -07:00
Jonathan Tan
5c3b801dab fetch-pack: do not lazy-fetch during ref iteration
In order to determine negotiation tips, "fetch-pack" iterates over all
refs and dereferences all annotated tags found. This causes the
existence of targets of refs and annotated tags to be checked. Avoiding
this is especially important when we use "git fetch" (which invokes
"fetch-pack") to perform lazy fetches in a partial clone because a
target of such a ref or annotated tag may need to be itself lazy-fetched
(and otherwise causing an infinite loop).

Therefore, teach "fetch-pack" not to lazy fetch whenever iterating over
refs. This is done by using the raw form of ref iteration and by
dereferencing tags ourselves.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 13:25:05 -07:00
Jonathan Tan
abcb7eeb31 fetch: only populate existing_refs if needed
In "fetch", get_ref_map() iterates over all refs to populate
"existing_refs" in order to populate peer_ref->old_oid in the returned
refmap, even if the refmap has no peer_ref set - which is the case when
only literal hashes (i.e. no refs by name) are fetched.

Iterating over refs causes the targets of those refs to be checked for
existence. Avoiding this is especially important when we use "git fetch"
to perform lazy fetches in a partial clone because a target of such a
ref may need to be itself lazy-fetched (and otherwise causing an
infinite loop).

Therefore, avoid populating "existing_refs" until necessary. With this
patch, because Git lazy-fetches objects by literal hashes (to be done in
a subsequent commit), it will then be able to guarantee avoiding reading
targets of refs.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 13:25:05 -07:00
Jonathan Tan
e5b942136e fetch: avoid reading submodule config until needed
In "fetch", there are two parameters submodule_fetch_jobs_config and
recurse_submodules that can be set in a variety of ways: through
.gitmodules, through .git/config, and through the command line.
Currently "fetch" handles this by first reading .gitmodules, then
reading .git/config (allowing it to overwrite existing values), then
reading the command line (allowing it to overwrite existing values).

Notice that we can avoid reading .gitmodules if .git/config and/or the
command line already provides us with what we need. In addition, if
recurse_submodules is found to be "no", we do not need the value of
submodule_fetch_jobs_config.

Avoiding reading .gitmodules is especially important when we use "git
fetch" to perform lazy fetches in a partial clone because the
.gitmodules file itself might need to be lazy fetched (and otherwise
causing an infinite loop).

In light of all this, avoid reading .gitmodules until necessary. When
reading it, we may only need one of the two parameters it provides, so
teach fetch_config_from_gitmodules() to support NULL arguments. With
this patch, users (including Git itself when invoking "git fetch" to
lazy-fetch) will be able to guarantee avoiding reading .gitmodules by
passing --recurse-submodules=no.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 13:25:05 -07:00
Jonathan Tan
2b713c272c fetch: allow refspecs specified through stdin
In a subsequent patch, partial clones will be taught to fetch missing
objects using a "git fetch" subprocess. Because the number of objects
fetched may be too numerous to fit on the command line, teach "fetch" to
accept refspecs passed through stdin.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 13:25:05 -07:00
Jonathan Tan
cbe566a071 negotiator/noop: add noop fetch negotiator
Add a noop fetch negotiator. This is introduced to allow partial clones
to skip the unneeded negotiation step when fetching missing objects
using a "git fetch" subprocess. (The implementation of spawning a "git
fetch" subprocess will be done in a subsequent patch.) But this can also
be useful for end users, e.g. as a blunt fix for object corruption.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 13:25:05 -07:00
Junio C Hamano
887952b8c6 fetch: optionally allow disabling FETCH_HEAD update
If you run fetch but record the result in remote-tracking branches,
and either if you do nothing with the fetched refs (e.g. you are
merely mirroring) or if you always work from the remote-tracking
refs (e.g. you fetch and then merge origin/branchname separately),
you can get away with having no FETCH_HEAD at all.

Teach "git fetch" a command line option "--[no-]write-fetch-head".
The default is to write FETCH_HEAD, and the option is primarily
meant to be used with the "--no-" prefix to override this default,
because there is no matching fetch.writeFetchHEAD configuration
variable to flip the default to off (in which case, the positive
form may become necessary to defeat it).

Note that under "--dry-run" mode, FETCH_HEAD is never written;
otherwise you'd see list of objects in the file that you do not
actually have.  Passing `--write-fetch-head` does not force `git
fetch` to write the file.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-18 12:56:57 -07:00