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Author SHA1 Message Date
Ævar Arnfjörð Bjarmason 6269f8eaad treewide: always have a valid "index_state.repo" member
When the "repo" member was added to "the_index" in [1] the
repo_read_index() was made to populate it, but the unpopulated
"the_index" variable didn't get the same treatment.

Let's do that in initialize_the_repository() when we set it up, and
likewise for all of the current callers initialized an empty "struct
index_state".

This simplifies code that needs to deal with "the_index" or a custom
"struct index_state", we no longer need to second-guess this part of
the "index_state" deep in the stack. A recent example of such
second-guessing is the "istate->repo ? istate->repo : the_repository"
code in [2]. We can now simply use "istate->repo".

We're doing this by making use of the INDEX_STATE_INIT() macro (and
corresponding function) added in [3], which now have mandatory "repo"
arguments.

Because we now call index_state_init() in repository.c's
initialize_the_repository() we don't need to handle the case where we
have a "repo->index" whose "repo" member doesn't match the "repo"
we're setting up, i.e. the "Complete the double-reference" code in
repo_read_index() being altered here. That logic was originally added
in [1], and was working around the lack of what we now have in
initialize_the_repository().

For "fsmonitor-settings.c" we can remove the initialization of a NULL
"r" argument to "the_repository". This was added back in [4], and was
needed at the time for callers that would pass us the "r" from an
"istate->repo". Before this change such a change to
"fsmonitor-settings.c" would segfault all over the test suite (e.g. in
t0002-gitfile.sh).

This change has wider eventual implications for
"fsmonitor-settings.c". The reason the other lazy loading behavior in
it is required (starting with "if (!r->settings.fsmonitor) ..." is
because of the previously passed "r" being "NULL".

I have other local changes on top of this which move its configuration
reading to "prepare_repo_settings()" in "repo-settings.c", as we could
now start to rely on it being called for our "r". But let's leave all
of that for now, and narrowly remove this particular part of the
lazy-loading.

1. 1fd9ae517c (repository: add repo reference to index_state,
   2021-01-23)
2. ee1f0c242e (read-cache: add index.skipHash config option,
   2023-01-06)
3. 2f6b1eb794 (cache API: add a "INDEX_STATE_INIT" macro/function,
   add release_index(), 2023-01-12)
4. 1e0ea5c431 (fsmonitor: config settings are repository-specific,
   2022-03-25)

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-17 14:32:06 -08:00
Ævar Arnfjörð Bjarmason 2f6b1eb794 cache API: add a "INDEX_STATE_INIT" macro/function, add release_index()
Hopefully in some not so distant future, we'll get advantages from always
initializing the "repo" member of the "struct index_state". To make
that easier let's introduce an initialization macro & function.

The various ad-hoc initialization of the structure can then be changed
over to it, and we can remove the various "0" assignments in
discard_index() in favor of calling index_state_init() at the end.

While not strictly necessary, let's also change the CALLOC_ARRAY() of
various "struct index_state *" to use an ALLOC_ARRAY() followed by
index_state_init() instead.

We're then adding the release_index() function and converting some
callers (including some of these allocations) over to it if they
either won't need to use their "struct index_state" again, or are just
about to call index_state_init().

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-16 10:46:58 -08:00
Ævar Arnfjörð Bjarmason 29fefafcba sparse-index API: BUG() out on NULL ensure_full_index()
Make the ensure_full_index() function stricter, and have it only
accept a non-NULL "struct index_state". This function (and this
behavior) was added in [1].

The only reason it needed to be this lax was due to interaction with
repo_index_has_changes(). See the addition of that code in [2].

The other reason for why this was needed dates back to interaction
with code added in [3]. In [4] we started calling ensure_full_index()
in unpack_trees(), but the caller added in 34110cd4e3 wants to pass
us a NULL "dst_index". Let's instead do the NULL check in
unpack_trees() itself.

1. 4300f8442a (sparse-index: implement ensure_full_index(), 2021-03-30)
2. 0c18c059a1 (read-cache: ensure full index, 2021-04-01)
3. 34110cd4e3 (Make 'unpack_trees()' have a separate source and
   destination index, 2008-03-06)
4. 6863df3550 (unpack-trees: ensure full index, 2021-03-30)

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-13 10:36:57 -08:00
Junio C Hamano d4c5400865 Merge branch 'ab/no-more-git-global-super-prefix'
Stop using "git --super-prefix" and narrow the scope of its use to
the submodule--helper.

* ab/no-more-git-global-super-prefix:
  read-tree: add "--super-prefix" option, eliminate global
  submodule--helper: convert "{update,clone}" to their own "--super-prefix"
  submodule--helper: convert "status" to its own "--super-prefix"
  submodule--helper: convert "sync" to its own "--super-prefix"
  submodule--helper: convert "foreach" to its own "--super-prefix"
  submodule--helper: don't use global --super-prefix in "absorbgitdirs"
  submodule.c & submodule--helper: pass along "super_prefix" param
  read-tree + fetch tests: test failing "--super-prefix" interaction
  submodule absorbgitdirs tests: add missing "Migrating git..." tests
2023-01-05 15:07:23 +09:00
Ævar Arnfjörð Bjarmason 4002ec3dcf read-tree: add "--super-prefix" option, eliminate global
The "--super-prefix" option to "git" was initially added in [1] for
use with "ls-files"[2], and shortly thereafter "submodule--helper"[3]
and "grep"[4]. It wasn't until [5] that "read-tree" made use of it.

At the time [5] made sense, but since then we've made "ls-files"
recurse in-process in [6], "grep" in [7], and finally
"submodule--helper" in the preceding commits.

Let's also remove it from "read-tree", which allows us to remove the
option to "git" itself.

We can do this because the only remaining user of it is the submodule
API, which will now invoke "read-tree" with its new "--super-prefix"
option. It will only do so when the "submodule_move_head()" function
is called.

That "submodule_move_head()" function was then only invoked by
"read-tree" itself, but now rather than setting an environment
variable to pass "--super-prefix" between cmd_read_tree() we:

- Set a new "super_prefix" in "struct unpack_trees_options". The
  "super_prefixed()" function in "unpack-trees.c" added in [5] will now
  use this, rather than get_super_prefix() looking up the environment
  variable we set earlier in the same process.

- Add the same field to the "struct checkout", which is only needed to
  ferry the "super_prefix" in the "struct unpack_trees_options" all the
  way down to the "entry.c" callers of "submodule_move_head()".

  Those calls which used the super prefix all originated in
  "cmd_read_tree()". The only other caller is the "unlink_entry()"
  caller in "builtin/checkout.c", which now passes a "NULL".

1. 74866d7579 (git: make super-prefix option, 2016-10-07)
2. e77aa336f1 (ls-files: optionally recurse into submodules, 2016-10-07)
3. 89c8626557 (submodule helper: support super prefix, 2016-12-08)
4. 0281e487fd (grep: optionally recurse into submodules, 2016-12-16)
5. 3d415425c7 (unpack-trees: support super-prefix option, 2017-01-17)
6. 188dce131f (ls-files: use repository object, 2017-06-22)
7. f9ee2fcdfa (grep: recurse in-process using 'struct repository', 2017-08-02)

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-26 10:21:44 +09:00
Seija Kijin 92cb135855 git: remove duplicate includes
These files are already included; we do not need to include them again

Signed-off-by: Seija Kijin <doremylover123@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-15 09:09:38 +09:00
Victoria Dye 68fcd48baf unpack-trees: add 'skip_cache_tree_update' option
Add (disabled by default) option to skip the 'cache_tree_update()' at the
end of 'unpack_trees()'. In many cases, this cache tree update is redundant
because the caller of 'unpack_trees()' immediately follows it with
'prime_cache_tree()', rebuilding the entire cache tree from scratch. While
these operations aren't the most expensive part of operations like 'git
reset', the duplicate calls still create a minor unnecessary slowdown.

Introduce an option for callers to skip the 'cache_tree_update()' in
'unpack_trees()' if it is redundant (that is, if 'prime_cache_tree()' is
called afterwards). At the moment, no 'unpack_trees()' callers use the new
option; they will be updated in subsequent patches.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-11-10 21:49:34 -05:00
Junio C Hamano fe3939bc2a Merge branch 'vd/sparse-reset-checkout-fixes'
Segfault fix-up to an earlier fix to the topic to teach "git reset"
and "git checkout" work better in a sparse checkout.

* vd/sparse-reset-checkout-fixes:
  unpack-trees: fix sparse directory recursion check
2022-09-09 12:02:26 -07:00
Victoria Dye 037f8ea6d9 unpack-trees: fix sparse directory recursion check
Ensure 'is_sparse_directory_entry()' receives a valid 'name_entry *' if one
exists in the list of tree(s) being unpacked in 'unpack_callback()'.

Currently, 'is_sparse_directory_entry()' is called with the first
'name_entry' in the 'names' list of entries on 'unpack_callback()'. However,
this entry may be empty even when other elements of 'names' are not (such as
when switching from an orphan branch back to a "normal" branch). As a
result, 'is_sparse_directory_entry()' could incorrectly indicate that a
sparse directory is *not* actually sparse because the name of the index
entry does not match the (empty) 'name_entry' path.

Fix the issue by using the existing 'name_entry *p' value in
'unpack_callback()', which points to the first non-empty entry in 'names'.
Because 'p' is 'const', also update 'is_sparse_directory_entry()'s
'name_entry *' argument to be 'const'.

Finally, add a regression test case.

Reported-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-02 09:43:09 -07:00
Junio C Hamano 80ffc849bd Merge branch 'vd/sparse-reset-checkout-fixes'
Fixes to sparse index compatibility work for "reset" and "checkout"
commands.

* vd/sparse-reset-checkout-fixes:
  unpack-trees: unpack new trees as sparse directories
  cache.h: create 'index_name_pos_sparse()'
  oneway_diff: handle removed sparse directories
  checkout: fix nested sparse directory diff in sparse index
2022-08-18 13:07:04 -07:00
Victoria Dye b15207b8cf unpack-trees: unpack new trees as sparse directories
If 'unpack_single_entry()' is unpacking a new directory tree (that is, one
not already present in the index) into a sparse index, unpack the tree as a
sparse directory rather than traversing its contents and unpacking each file
individually. This helps keep the sparse index as collapsed as possible in
cases such as 'git reset --hard' restoring a outside-of-cone directory
removed with 'git rm -r --sparse'.

Without this patch, 'unpack_single_entry()' will only unpack a directory
into the index as a sparse directory (rather than traversing into it and
unpacking its files one-by-one) if an entry with the same name already
exists in the index. This patch allows sparse directory unpacking without a
matching index entry when the following conditions are met:

1. the directory's path is outside the sparse cone, and
2. there are no children of the directory in the index

If a directory meets these requirements (as determined by
'is_new_sparse_dir()'), 'unpack_single_entry()' unpacks the sparse directory
index entry and propagates the decision back up to 'unpack_callback()' to
prevent unnecessary tree traversal into the unpacked directory.

Reported-by: Shaoxuan Yuan <shaoxuan.yuan02@gmail.com>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-08 13:21:50 -07:00
Matheus Tavares 611c7785e8 checkout: fix two bugs on the final count of updated entries
At the end of `git checkout <pathspec>`, we get a message informing how
many entries were updated in the working tree. However, this number can
be inaccurate for two reasons:

1) Delayed entries currently get counted twice.
2) Failed entries are included in the count.

The first problem happens because the counter is first incremented
before inserting the entry in the delayed checkout queue, and once again
when finish_delayed_checkout() calls checkout_entry(). And the second
happens because the counter is incremented too early in
checkout_entry(), before the entry was in fact checked out. Fix that by
moving the count increment further down in the call stack and removing
the duplicate increment on delayed entries. Note that we have to keep
a per-entry reference for the counter (both on parallel checkout and
delayed checkout) because not all entries are always accumulated at the
same counter. See checkout_worktree(), at builtin/checkout.c for an
example.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-14 10:19:28 -07:00
Junio C Hamano 9e496fffc8 Merge branch 'jh/builtin-fsmonitor-part3'
More fsmonitor--daemon.

* jh/builtin-fsmonitor-part3: (30 commits)
  t7527: improve implicit shutdown testing in fsmonitor--daemon
  fsmonitor--daemon: allow --super-prefix argument
  t7527: test Unicode NFC/NFD handling on MacOS
  t/lib-unicode-nfc-nfd: helper prereqs for testing unicode nfc/nfd
  t/helper/hexdump: add helper to print hexdump of stdin
  fsmonitor: on macOS also emit NFC spelling for NFD pathname
  t7527: test FSMonitor on case insensitive+preserving file system
  fsmonitor: never set CE_FSMONITOR_VALID on submodules
  t/perf/p7527: add perf test for builtin FSMonitor
  t7527: FSMonitor tests for directory moves
  fsmonitor: optimize processing of directory events
  fsm-listen-darwin: shutdown daemon if worktree root is moved/renamed
  fsm-health-win32: force shutdown daemon if worktree root moves
  fsm-health-win32: add polling framework to monitor daemon health
  fsmonitor--daemon: stub in health thread
  fsmonitor--daemon: rename listener thread related variables
  fsmonitor--daemon: prepare for adding health thread
  fsmonitor--daemon: cd out of worktree root
  fsm-listen-darwin: ignore FSEvents caused by xattr changes on macOS
  unpack-trees: initialize fsmonitor_has_run_once in o->result
  ...
2022-06-10 15:04:15 -07:00
Junio C Hamano c276c21da6 Merge branch 'ds/sparse-sparse-checkout'
"sparse-checkout" learns to work well with the sparse-index
feature.

* ds/sparse-sparse-checkout:
  sparse-checkout: integrate with sparse index
  p2000: add test for 'git sparse-checkout [add|set]'
  sparse-index: complete partial expansion
  sparse-index: partially expand directories
  sparse-checkout: --no-sparse-index needs a full index
  cache-tree: implement cache_tree_find_path()
  sparse-index: introduce partially-sparse indexes
  sparse-index: create expand_index()
  t1092: stress test 'git sparse-checkout set'
  t1092: refactor 'sparse-index contents' test
2022-06-03 14:30:35 -07:00
Jeff Hostetler 9968ed73ff unpack-trees: initialize fsmonitor_has_run_once in o->result
Initialize `o->result.fsmonitor_has_run_once` based upon value
in `o->src_index->fsmonitor_has_run_once` to prevent a second
fsmonitor query during the tree traversal and possibly getting
a skewed view of the working directory.

The checkout code has already talked to the fsmonitor and the
traversal is updating the index as it traverses, so there is
no need to query the fsmonitor.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:59:26 -07:00
Derrick Stolee 598b1e7d09 sparse-checkout: integrate with sparse index
When modifying the sparse-checkout definition, the sparse-checkout
builtin calls update_sparsity() to modify the SKIP_WORKTREE bits of all
cache entries in the index. Before, we needed the index to be fully
expanded in order to ensure we had the full list of files necessary that
match the new patterns.

Insert a call to reset_sparse_directories() that expands sparse
directories that are within the new pattern list, but only far enough
that every necessary file path now exists as a cache entry. The
remaining logic within update_sparsity() will modify the SKIP_WORKTREE
bits appropriately.

This allows us to disable command_requires_full_index within the
sparse-checkout builtin. Add tests that demonstrate that we are not
expanding to a full index unnecessarily.

We can see the improved performance in the p2000 test script:

Test                           HEAD~1            HEAD
------------------------------------------------------------------------
2000.24: git ... (sparse-v3)   2.14(1.55+0.58)   1.57(1.03+0.53) -26.6%
2000.25: git ... (sparse-v4)   2.20(1.62+0.57)   1.58(0.98+0.59) -28.2%

These reductions of 26-28% are small compared to most examples, but the
time is dominated by writing a new copy of the base repository to the
worktree and then deleting it again. The fact that the previous index
expansion was such a large portion of the time is telling how important
it is to complete this sparse index integration.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-23 11:08:22 -07:00
Victoria Dye 0f329b9ae4 unpack-trees: preserve index sparsity
When unpacking trees, set the default sparsity of the resultant index based
on repo settings and 'is_sparse_index_allowed()'.

Normally, when executing 'unpack_trees', the output index is marked sparse
when (and only when) it unpacks a sparse directory. However, an index may be
"sparse" even if it contains no sparse directories - when all files fall
inside the sparse-checkout definition or otherwise have SKIP_WORKTREE
disabled. Therefore, the output index may be marked "full" even when it is
"sparse", resulting in unnecessary 'ensure_full_index' calls when writing to
disk. Avoid this by setting the "default" index sparsity to match what is
expected for the repository.

As a consequence of this fix, the (non-merge) 'read-tree' performed when
applying a stash with untracked files no longer expands the index. Update
the corresponding test in 't1092'.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-10 16:45:13 -07:00
Victoria Dye 99430aa12c Revert "unpack-trees: improve performance of next_cache_entry"
This reverts commit f2a454e0a5 (unpack-trees: improve performance of
next_cache_entry, 2021-11-29).

The "hint" value was originally needed to improve performance in 'git reset
-- <pathspec>' caused by 'cache_bottom' lagging behind its correct value
when using a sparse index. The 'cache_bottom' tracking has since been
corrected, removing the need for an additional "pseudo-cache_bottom"
tracking variable.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-17 09:13:21 -07:00
Victoria Dye bfc763df77 unpack-trees: increment cache_bottom for sparse directories
Correct tracking of the 'cache_bottom' for cases where sparse directories
are present in the index.

BACKGROUND
----------
The 'unpack_trees_options.cache_bottom' is a variable that tracks the
in-progress "bottom" of the cache as 'unpack_trees()' iterates through the
contents of the index. Most importantly, this value informs the sequential
return values of 'next_cache_entry()' which, in the "diff cache" usage of
'unpack_callback()', are either unpacked as-is or are passed into the diff
machinery.

The 'cache_bottom' is intended to track the position of the first entry in
the index that has not yet been diffed or unpacked. It is advanced in two
main ways: either it is incremented when an index entry is marked as "used"
(in 'mark_ce_used()'), indicating that it was unpacked or diffed, or when a
directory is unpacked, in which case it is increased by an amount equaling
the number of index entries inside that tree.

In 17a1bb570b (unpack-trees: preserve cache_bottom, 2021-07-14), it was
identified that sparse directories posed a problem to the above
'cache_bottom' advancement logic - because a sparse directory was both an
index entry that could be "used" and a directory that can be unpacked, the
'cache_bottom' would be incremented too many times. To solve this problem,
the 'mark_ce_used()' advancement of 'cache_bottom' was skipped for sparse
directories.

INCORRECT CACHE_BOTTOM TRACKING
-------------------------------
Skipping the 'cache_bottom' advancement for sparse directories in
'mark_ce_used()' breaks down in two cases:

1. When the 'unpack_trees()' operation is *not* a "cache diff" (because the
   directory contents-based incrementing of 'cache_bottom' does not happen).
2. When a cache diff is performed with a pathspec (because
   'unpack_index_entry()' will unpack a sparse directory not matched by the
   pathspec without performing the directory contents-based increment).

The former luckily does not appear to affect 'git' behavior, likely because
'cache_bottom' is largely unused (non-"cache diff" 'unpack_trees()' uses
'find_index_entry()' - rather than 'next_cache_entry()' - to find the index
entries to unpack).

The latter, however, causes 'cache_bottom' to "lag behind" its intended
position by an amount equal to the number of sparse directories unpacked so
far with 'unpack_index_entry()'. If a repository is structured such that any
sparse directories are ordered lexicographically *after* any
pathspec-matching directories, though, this issue won't present any adverse
behavior.

This was the case with the 't1092-sparse-checkout-compatibility.sh' tests
before the addition of the 'before/' sparse directory (ordered *before* the
in-cone 'deep/' directory), therefore sidestepping the issue. Once the
'before/' directory was added, though, 'cache_bottom' began to lag behind
its intended position, causing 'next_cache_entry()' to return index entries
it had already processed and, ultimately, an incorrect diff.

CORRECTING CACHE_BOTTOM
-----------------------
The problems observed in 't1092' come from 'cache_bottom' lagging behind in
cases where the cache tree-based advancement doesn't occur. To solve this,
then, the fix in 17a1bb570b is "reversed"; rather than skipping
'cache_bottom' advancement in 'mark_ce_used()', we skip the directory
contents-based advancement for sparse directories. Now, every index entry
can be accounted for in 'cache_bottom':

* if you're working with a single index entry, 'cache_bottom' is incremented
  in 'mark_ce_used()'
* if you're working with a directory that contains index entries (but is not
  one itself), 'cache_bottom' is incremented by the number of entries in
  that directory.

Finally, change the 'test_expect_failure' tests in 't1092' failing due to
this bug back to 'test_expect_success'.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-17 09:13:21 -07:00
Junio C Hamano 190f9bf62a Merge branch 'vd/sparse-read-tree'
"git read-tree" has been made to be aware of the sparse-index
feature.

* vd/sparse-read-tree:
  read-tree: make three-way merge sparse-aware
  read-tree: make two-way merge sparse-aware
  read-tree: narrow scope of index expansion for '--prefix'
  read-tree: integrate with sparse index
  read-tree: expand sparse checkout test coverage
  read-tree: explicitly disallow prefixes with a leading '/'
  status: fix nested sparse directory diff in sparse index
  sparse-index: prevent repo root from becoming sparse
2022-03-16 17:53:08 -07:00
Victoria Dye f27c170f64 read-tree: make three-way merge sparse-aware
Enable use of 'merged_sparse_dir' in 'threeway_merge'. As with two-way
merge, the contents of each conflicted sparse directory are merged without
referencing the index, avoiding sparse index expansion.

As with two-way merge, the 't/t1092-sparse-checkout-compatibility.sh' test
'read-tree --merge with edit/edit conflicts in sparse directories' confirms
that three-way merges with edit/edit changes (both with and without
conflicts) inside a sparse directory result in the correct index state or
error message. To ensure the index is not unnecessarily expanded, add
three-way merge cases to 'sparse index is not expanded: read-tree'.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-01 12:36:01 -08:00
Victoria Dye ab81047a6c read-tree: make two-way merge sparse-aware
Enable two-way merge with 'git read-tree' without expanding the sparse
index. When in a sparse index, a two-way merge will trivially succeed as
long as there are not changes to the same sparse directory in multiple trees
(i.e., sparse directory-level "edit-edit" conflicts). If there are such
conflicts, the merge will fail despite the possibility that individual files
could merge cleanly.

In order to resolve these "edit-edit" conflicts, "conflicted" sparse
directories are - rather than rejected - merged by traversing their
associated trees by OID. For each child of the sparse directory:

1. Files are merged as normal (see Documentation/git-read-tree.txt for
   details).
2. Subdirectories are treated as sparse directories and merged in
   'twoway_merge'. If there are no conflicts, they are merged according to
   the rules in Documentation/git-read-tree.txt; otherwise, the subdirectory
   is recursively traversed and merged.

This process allows sparse directories to be individually merged at the
necessary depth *without* expanding a full index.

The 't/t1092-sparse-checkout-compatibility.sh' test 'read-tree --merge with
edit/edit conflicts in sparse directories' tests two-way merges with 1)
changes inside sparse directories that do not conflict and 2) changes that
do conflict (with the correct file(s) reported in the error message).
Additionally, add two-way merge cases to 'sparse index is not expanded:
read-tree' to confirm that the index is not expanded regardless of whether
edit/edit conflicts are present in a sparse directory.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-01 12:36:01 -08:00
Victoria Dye 7497039241 read-tree: narrow scope of index expansion for '--prefix'
When 'git read-tree' is provided with a prefix, expand the index only if the
prefix is equivalent to a sparse directory or contained within one. If the
index is not expanded in these cases, 'ce_in_traverse_path' will indicate
that the relevant sparse directory is not in the prefix/traverse path,
skipping past it and not unpacking the appropriate tree(s).

If the prefix is in-cone, its sparse subdirectories (if any) will be
traversed correctly without index expansion.

The behavior of 'git read-tree' with prefixes 1) inside of cone, 2) equal to
a sparse directory, and 3) inside a sparse directory are all tested as part
of the 't/t1092-sparse-checkout-compatibility.sh' test 'read-tree --prefix',
ensuring that the sparse index case works the way it did prior to this
change as well as matching non-sparse index sparse-checkout.

Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-01 12:36:01 -08:00
Elijah Newren 26b5d6b0e5 unpack-trees: fix accidental loss of user changes
For sparse-checkouts, we don't want unpack-trees to error out on files
that are missing from the worktree, so there has traditionally been
logic to make it skip the verify_uptodate() check for these.
Unfortunately, it was skipping the verify_uptodate() check for files
that were expected to *become* SKIP_WORKTREE.  For files that were not
already SKIP_WORKTREE, that can cause us to later delete the file in
apply_sparse_checkout().  Only skip the check for files that were
already SKIP_WORKTREE as well to avoid lightly discarding important
changes users may have made to files.

Note 1: unpack-trees.c is already a bit complex, and the logic around
CE_SKIP_WORKTREE and CE_NEW_SKIP_WORKTREE in that file are no exception.
I also tried just replacing CE_NEW_SKIP_WORKTREE with CE_SKIP_WORKTREE
in the verify_uptodate() check instead of checking for both flags, and
found that it also fixed this bug and passed all the tests.  I also
attempted to devise a few testcases that might trip either variant of my
fix and was unable to find any problems.  It may be that just checking
CE_SKIP_WORKTREE is a better fix, but I'm not sure.  I thought it
was a bit safer to strictly reduce the number of cases where we skip the
up-to-date check rather than just toggling which kind of cases skip it,
and thus went with the current variant of the fix.

Note 2: I also wondered if verify_absent() might have a similar bug, but
despite my attempts to try to devise a testcase that would trigger such
a thing, I couldn't find any problematic testcases.  Thus, this patch
makes no attempt to apply similar changes to verify_absent() and
verify_absent_if_directory().

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-14 14:42:20 -08:00
Junio C Hamano da81d473fc Merge branch 'en/keep-cwd'
Many git commands that deal with working tree files try to remove a
directory that becomes empty (i.e. "git switch" from a branch that
has the directory to another branch that does not would attempt
remove all files in the directory and the directory itself).  This
drops users into an unfamiliar situation if the command was run in
a subdirectory that becomes subject to removal due to the command.
The commands have been taught to keep an empty directory if it is
the directory they were started in to avoid surprising users.

* en/keep-cwd:
  t2501: simplify the tests since we can now assume desired behavior
  dir: new flag to remove_dir_recurse() to spare the original_cwd
  dir: avoid incidentally removing the original_cwd in remove_path()
  stash: do not attempt to remove startup_info->original_cwd
  rebase: do not attempt to remove startup_info->original_cwd
  clean: do not attempt to remove startup_info->original_cwd
  symlinks: do not include startup_info->original_cwd in dir removal
  unpack-trees: add special cwd handling
  unpack-trees: refuse to remove startup_info->original_cwd
  setup: introduce startup_info->original_cwd
  t2501: add various tests for removing the current working directory
2022-01-05 14:01:28 -08:00
Junio C Hamano e1d9288267 Merge branch 'ds/sparse-deep-pattern-checkout-fix'
The sparse-index/sparse-checkout feature had a bug in its use of
the matching code to determine which path is in or outside the
sparse checkout patterns.

* ds/sparse-deep-pattern-checkout-fix:
  unpack-trees: use traverse_path instead of name
  t1092: add deeper changes during a checkout
2021-12-15 09:39:50 -08:00
Junio C Hamano f0850875fd Merge branch 'vd/sparse-reset'
Various operating modes of "git reset" have been made to work
better with the sparse index.

* vd/sparse-reset:
  unpack-trees: improve performance of next_cache_entry
  reset: make --mixed sparse-aware
  reset: make sparse-aware (except --mixed)
  reset: integrate with sparse index
  reset: expand test coverage for sparse checkouts
  sparse-index: update command for expand/collapse test
  reset: preserve skip-worktree bit in mixed reset
  reset: rename is_missing to !is_in_reset_tree
2021-12-10 14:35:12 -08:00
Elijah Newren 0b0ee3388c unpack-trees: add special cwd handling
When running commands such as `git reset --hard` from a subdirectory, if
that subdirectory is in the way of adding needed files, bail with an
error message.

Note that this change looks kind of like it duplicates the new lines of
code from the previous commit in verify_clean_subdirectory().  However,
when we are preserving untracked files, we would rather any error
messages about untracked files being in the way take precedence over
error messages about a subdirectory that happens to be the_original_cwd
being in the way.  But in the UNPACK_RESET_OVERWRITE_UNTRACKED case,
there is no untracked checking to be done, so we simply add a special
case near the top of verify_absent_1.

Acked-by: Derrick Stolee <stolee@gmail.com>
Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:33:12 -08:00
Elijah Newren b817e54533 unpack-trees: refuse to remove startup_info->original_cwd
In the past, when a directory needs to be removed to make room for a
file, we have always errored out when that directory contains any
untracked (but not ignored) files.  Add an extra condition on that: also
error out if the directory is the current working directory we inherited
from our parent process.

Acked-by: Derrick Stolee <stolee@gmail.com>
Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:33:12 -08:00
Derrick Stolee 8c5de0d265 unpack-trees: use traverse_path instead of name
The sparse_dir_matches_path() method compares a cache entry that is a
sparse directory entry against a 'struct traverse_info *info' and a
'struct name_entry *p' to see if the cache entry has exactly the right
name for those other inputs.

This method was introduced in 523506d (unpack-trees: unpack sparse
directory entries, 2021-07-14), but included a significant mistake. The
path comparisons used 'info->name' instead of 'info->traverse_path'.
Since 'info->name' only stores a single tree entry name while
'info->traverse_path' stores the full path from root, this method does
not work when 'info' is in a subdirectory of a directory. Replacing the
right strings and their corresponding lengths make the method work
properly.

The previous change included a failing test that exposes this issue.
That test now passes. The critical detail is that as we go deep into
unpack_trees(), the logic for merging a sparse directory entry with a
tree entry during 'git checkout' relies on this
sparse_dir_matches_path() in order to avoid calling
traverse_trees_recursive() during unpack_callback() in this hunk:

	if (!is_sparse_directory_entry(src[0], names, info) &&
	    traverse_trees_recursive(n, dirmask, mask & ~dirmask,
					    names, info) < 0) {
		return -1;
	}

For deep paths, the short-circuit never occurred and
traverse_trees_recursive() was being called incorrectly and that was
causing other strange issues. Specifically, the error message from the
now-passing test previously included this:

      error: Your local changes to the following files would be overwritten by checkout:
              deep/deeper1/deepest2/a
              deep/deeper1/deepest3/a
      Please commit your changes or stash them before you switch branches.
      Aborting

These messages occurred because the 'current' cache entry in
twoway_merge() was showing as NULL because the index did not contain
entries for the paths contained within the sparse directory entries. We
instead had 'oldtree' given as the entry at HEAD and 'newtree' as the
entry in the target tree. This led to reject_merge() listing these
paths.

Now that sparse_dir_matches_path() works the same for deep paths as it
does for shallow depths, the rest of the logic kicks in to properly
handle modifying the sparse directory entries as designed.

Reported-by: Gustave Granroth <gus.gran@gmail.com>
Reported-by: Mike Marcelais <michmarc@exchange.microsoft.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:24:54 -08:00
Victoria Dye f2a454e0a5 unpack-trees: improve performance of next_cache_entry
To find the first non-unpacked cache entry, `next_cache_entry` iterates
through index, starting at `cache_bottom`. The performance of this in full
indexes is helped by `cache_bottom` advancing with each invocation of
`mark_ce_used` (called by `unpack_index_entry`). However, the presence of
sparse directories can prevent the `cache_bottom` from advancing in a sparse
index case, effectively forcing `next_cache_entry` to search from the
beginning of the index each time it is called.

The `cache_bottom` must be preserved for the sparse index (see 17a1bb570b
(unpack-trees: preserve cache_bottom, 2021-07-14)). Therefore, to retain the
benefit `cache_bottom` provides in non-sparse index cases, a separate `hint`
position indicates the first position `next_cache_entry` should search,
updated each execution with a new position.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-29 12:51:26 -08:00
Junio C Hamano bfa646c2cb Merge branch 'ab/unpack-trees-leakfix'
Leakfix.

* ab/unpack-trees-leakfix:
  sequencer: fix a memory leak in do_reset()
  sequencer: add a "goto cleanup" to do_reset()
  unpack-trees: don't leak memory in verify_clean_subdirectory()
2021-10-25 16:06:56 -07:00
Junio C Hamano a7c2daa06d Merge branch 'en/removing-untracked-fixes'
Various fixes in code paths that move untracked files away to make room.

* en/removing-untracked-fixes:
  Documentation: call out commands that nuke untracked files/directories
  Comment important codepaths regarding nuking untracked files/dirs
  unpack-trees: avoid nuking untracked dir in way of locally deleted file
  unpack-trees: avoid nuking untracked dir in way of unmerged file
  Change unpack_trees' 'reset' flag into an enum
  Remove ignored files by default when they are in the way
  unpack-trees: make dir an internal-only struct
  unpack-trees: introduce preserve_ignored to unpack_trees_options
  read-tree, merge-recursive: overwrite ignored files by default
  checkout, read-tree: fix leak of unpack_trees_options.dir
  t2500: add various tests for nuking untracked files
2021-10-13 15:15:57 -07:00
Ævar Arnfjörð Bjarmason e5a917fcf4 unpack-trees: don't leak memory in verify_clean_subdirectory()
Fix two different but related memory leaks in
verify_clean_subdirectory(). We leaked both the "pathbuf" if
read_directory() returned non-zero, and we never cleaned up our own
"struct dir_struct" either.

 * "pathbuf": When the read_directory() call followed by the
   free(pathbuf) was added in c81935348b (Fix switching to a branch
   with D/F when current branch has file D., 2007-03-15) we didn't
   bother to free() before we called die().

   But when this code was later libified in 203a2fe117 (Allow callers
   of unpack_trees() to handle failure, 2008-02-07) we started to leak
   as we returned data to the caller. This fixes that memory leak,
   which can be observed under SANITIZE=leak with e.g. the
   "t1001-read-tree-m-2way.sh" test.

 * "struct dir_struct": We've leaked the dir_struct ever since this
   code was added back in c81935348b.

   When that commit was written there wasn't an equivalent of
   dir_clear(). Since it was added in 270be81604 (dir.c: provide
   clear_directory() for reclaiming dir_struct memory, 2013-01-06)
   we've omitted freeing the memory allocated here.

   This memory leak could also be observed under SANITIZE=leak and the
   "t1001-read-tree-m-2way.sh" test.

This makes all the test in "t1001-read-tree-m-2way.sh" pass under
"GIT_TEST_PASSING_SANITIZE_LEAK=true", we'd previously die in tests
25, 26 & 28.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-07 15:29:02 -07:00
Elijah Newren 56d06fe4aa unpack-trees: avoid nuking untracked dir in way of locally deleted file
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 13:38:37 -07:00
Elijah Newren 1fdd51aa13 unpack-trees: avoid nuking untracked dir in way of unmerged file
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 13:38:37 -07:00
Elijah Newren 480d3d6bf9 Change unpack_trees' 'reset' flag into an enum
Traditionally, unpack_trees_options->reset was used to signal that it
was okay to delete any untracked files in the way.  This was used by
`git read-tree --reset`, but then started appearing in other places as
well.  However, many of the other uses should not be deleting untracked
files in the way.  Change this value to an enum so that a value of 1
(i.e. "true") can be split into two:
   UNPACK_RESET_PROTECT_UNTRACKED,
   UNPACK_RESET_OVERWRITE_UNTRACKED
In order to catch accidental misuses (i.e. where folks call it the way
they traditionally used to), define the special enum value of
   UNPACK_RESET_INVALID = 1
which will trigger a BUG().

Modify existing callers so that
   read-tree --reset
   reset --hard
   checkout --force
continue using the UNPACK_RESET_OVERWRITE_UNTRACKED logic, while other
callers, including
   am
   checkout without --force
   stash  (though currently dead code; reset always had a value of 0)
   numerous callers from rebase/sequencer to reset_head()
will use the new UNPACK_RESET_PROTECT_UNTRACKED value.

Also, note that it has been reported that 'git checkout <treeish>
<pathspec>' currently also allows overwriting untracked files[1].  That
case should also be fixed, but it does not use unpack_trees() and thus
is outside the scope of the current changes.

[1] https://lore.kernel.org/git/15dad590-087e-5a48-9238-5d2826950506@gmail.com/

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 13:38:37 -07:00
Elijah Newren c42e0b6409 unpack-trees: make dir an internal-only struct
Avoid accidental misuse or confusion over ownership by clearly making
unpack_trees_options.dir an internal-only variable.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 13:38:37 -07:00
Elijah Newren 04988c8d18 unpack-trees: introduce preserve_ignored to unpack_trees_options
Currently, every caller of unpack_trees() that wants to ensure ignored
files are overwritten by default needs to:
   * allocate unpack_trees_options.dir
   * flip the DIR_SHOW_IGNORED flag in unpack_trees_options.dir->flags
   * call setup_standard_excludes
AND then after the call to unpack_trees() needs to
   * call dir_clear()
   * deallocate unpack_trees_options.dir
That's a fair amount of boilerplate, and every caller uses identical
code.  Make this easier by instead introducing a new boolean value where
the default value (0) does what we want so that new callers of
unpack_trees() automatically get the appropriate behavior.  And move all
the handling of unpack_trees_options.dir into unpack_trees() itself.

While preserve_ignored = 0 is the behavior we feel is the appropriate
default, we defer fixing commands to use the appropriate default until a
later commit.  So, this commit introduces several locations where we
manually set preserve_ignored=1.  This makes it clear where code paths
were previously preserving ignored files when they should not have been;
a future commit will flip these to instead use a value of 0 to get the
behavior we want.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 13:38:37 -07:00
Junio C Hamano dc89c34d9e Merge branch 'ds/sparse-index-ignored-files'
In cone mode, the sparse-index code path learned to remove ignored
files (like build artifacts) outside the sparse cone, allowing the
entire directory outside the sparse cone to be removed, which is
especially useful when the sparse patterns change.

* ds/sparse-index-ignored-files:
  sparse-checkout: clear tracked sparse dirs
  sparse-index: add SPARSE_INDEX_MEMORY_ONLY flag
  attr: be careful about sparse directories
  sparse-checkout: create helper methods
  sparse-index: use WRITE_TREE_MISSING_OK
  sparse-index: silently return when cache tree fails
  unpack-trees: fix nested sparse-dir search
  sparse-index: silently return when not using cone-mode patterns
  t7519: rewrite sparse index test
2021-09-20 15:20:44 -07:00
Junio C Hamano fd0d7036e0 Merge branch 'ab/retire-advice-config'
Code clean up to migrate callers from older advice_config[] based
API to newer advice_if_enabled() and advice_enabled() API.

* ab/retire-advice-config:
  advice: move advice.graftFileDeprecated squashing to commit.[ch]
  advice: remove use of global advice_add_embedded_repo
  advice: remove read uses of most global `advice_` variables
  advice: add enum variants for missing advice variables
2021-09-10 11:46:29 -07:00
Derrick Stolee 72d84ea347 unpack-trees: fix nested sparse-dir search
The iterated search in find_cache_entry() was recently modified to
include a loop that searches backwards for a sparse directory entry that
matches the given traverse_info and name_entry. However, the string
comparison failed to actually concatenate those two strings, so this
failed to find a sparse directory when it was not a top-level directory.

This caused some errors in rare cases where a 'git checkout' spanned a
diff that modified files within the sparse directory entry, but we could
not correctly find the entry.

Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Helped-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-07 22:41:09 -07:00
Matheus Tavares 7a132c628e checkout: make delayed checkout respect --quiet and --no-progress
The 'Filtering contents...' progress report from delayed checkout is
displayed even when checkout and clone are invoked with --quiet or
--no-progress. Furthermore, it is displayed unconditionally, without
first checking whether stdout is a tty. Let's fix these issues and also
add some regression tests for the two code paths that currently use
delayed checkout: unpack_trees.c:check_updates() and
builtin/checkout.c:checkout_worktree().

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-26 23:15:33 -07:00
Ben Boeckel ed9bff0817 advice: remove read uses of most global `advice_` variables
In c4a09cc9cc (Merge branch 'hw/advise-ng', 2020-03-25), a new API for
accessing advice variables was introduced and deprecated `advice_config`
in favor of a new array, `advice_setting`.

This patch ports all but two uses which read the status of the global
`advice_` variables over to the new `advice_enabled` API. We'll deal
with advice_add_embedded_repo and advice_graft_file_deprecated
separately.

Signed-off-by: Ben Boeckel <mathstuf@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-25 12:07:52 -07:00
Junio C Hamano 506d2a354a Merge branch 'ds/commit-and-checkout-with-sparse-index'
"git checkout" and "git commit" learn to work without unnecessarily
expanding sparse indexes.

* ds/commit-and-checkout-with-sparse-index:
  unpack-trees: resolve sparse-directory/file conflicts
  t1092: document bad 'git checkout' behavior
  checkout: stop expanding sparse indexes
  sparse-index: recompute cache-tree
  commit: integrate with sparse-index
  p2000: compress repo names
  p2000: add 'git checkout -' test and decrease depth
2021-08-04 13:28:53 -07:00
Junio C Hamano 8230107f33 Merge branch 'jt/bulk-prefetch'
"git read-tree" had a codepath where blobs are fetched one-by-one
from the promisor remote, which has been corrected to fetch in bulk.

* jt/bulk-prefetch:
  cache-tree: prefetch in partial clone read-tree
  unpack-trees: refactor prefetching code
2021-08-02 14:06:42 -07:00
Jonathan Tan b2896d2739 unpack-trees: refactor prefetching code
Refactor the prefetching code in unpack-trees.c into its own function,
because it will be used elsewhere in a subsequent commit.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-23 14:21:57 -07:00
Derrick Stolee e05cdb17e8 unpack-trees: resolve sparse-directory/file conflicts
When running unpack_trees() with a sparse index, we attempt to operate
on the index without expanding the sparse directory entries. Thus, we
operate by manipulating entire directories and passing them to the
unpack function. In the case of the 'git checkout' command, this is the
twoway_merge() function.

There are several cases in twoway_merge() that handle different
situations. One new one to add is the case of a directory/file conflict
where the directory is sparse. Before the sparse index, such a conflict
would appear as a list of file additions and deletions. Now,
twoway_merge() initializes 'current', 'oldtree', and 'newtree' from
src[0], src[1], and src[2], then sets 'oldtree' to NULL because it is
equal to the df_conflict_entry. The way to determine that we have a
directory/file conflict is to test that 'current' and 'newtree' disagree
on being sparse directory entries.

When we are in this case, we want to resolve the situation by calling
merged_entry(). This allows replacing the 'current' entry with the
'newtree' entry. This is important for cases where we want to run 'git
checkout' across the conflict and have the new HEAD represent the new
file type at that path. The first NEEDSWORK comment dropped in t1092
demonstrates this necessary behavior.

However, we still are in a confusing state when 'current' corresponds to
a staged change within a sparse directory that is not present at HEAD.
This should be atypical, because it requires adding a change outside of
the sparse-checkout cone, but it is possible. Since we are unable to
determine that this is a staged change within twoway_merge(), we cannot
add a case to reject the merge at this point. I believe this is due to
the use of df_conflict_entry in the place of 'oldtree' instead of using
the valud at HEAD, which would provide some perspective to this
decision. Any change that would allow this differentiation for staged
entries would need to involve information further up in unpack_trees().

That work should be done, sometime, because we are further confusing the
behavior of a directory/file conflict when staging a change in the
directory. The two cases 'checkout behaves oddly with df-conflict-?' in
t1092 demonstrate that even without a sparse-checkout, Git is not
consistent in its behavior. Neither of the two options seems correct,
either. This change makes the sparse-index behave differently than the
typcial sparse-checkout case, but it does match the full checkout
behavior in the df-conflict-2 case.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-20 14:59:11 -07:00
Derrick Stolee 523506df51 unpack-trees: unpack sparse directory entries
During unpack_callback(), index entries are compared against tree
entries. These are matched according to names and types. One goal is to
decide if we should recurse into subtrees or simply operate on one index
entry.

In the case of a sparse-directory entry, we do not want to recurse into
that subtree and instead simply compare the trees. In some cases, we
might want to perform a merge operation on the entry, such as during
'git checkout <commit>' which wants to replace a sparse tree entry with
the tree for that path at the target commit. We extend the logic within
unpack_single_entry() to create a sparse-directory entry in this case,
and then that is sent to call_unpack_fn().

There are some subtleties in this process. For instance, we need to
update find_cache_entry() to allow finding a sparse-directory entry that
exactly matches a given path. Use the new helper method
sparse_dir_matches_path() for this. We also need to ignore conflict
markers in the case that the entries correspond to directories and we
already have a sparse directory entry.

Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-14 13:42:49 -07:00
Derrick Stolee bd6a3fd7f1 unpack-trees: rename unpack_nondirectories()
In the next change, we will use this method to unpack a sparse directory
entry, so change the name to unpack_single_entry() so these entries
apply. The new name reflects that we will not recurse into trees in
order to resolve the conflicts.

Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-14 13:42:49 -07:00