Commit Graph

73443 Commits

Author SHA1 Message Date
Jeff King
6d107751b2 sparse-checkout: free duplicate hashmap entries
In insert_recursive_pattern(), we create a new pattern_entry to insert
into the parent_hashmap. If we find that the same entry already exists
in the hashmap, we skip adding the new one. But we forget to free the new
one, creating a leak.

We can fix it by cleaning up the discarded entry. It would probably be
possible to avoid creating it in the first place, but it's non-trivial.
We'd have to define a "keydata" struct that lets us compare the existing
entries to the broken-out fields. It's probably not worth the
complexity, so we'll punt on that for now.

There is one subtlety here: our insertion is happening in a loop, with
each iteration looking at the pattern we just inserted (hence the
"recursive" in the name). So if we skip insertion, what do we look at?

The obvious answer is that we should remember the existing duplicate we
found and use that. But I _think_ in that case, we probably already have
all of the recursive bits already (from when the original entry was
added). And so just breaking out of the loop would be correct. But I'm
not 100% sure on that; after all, the original leaky code could have
done the same break, but it didn't.

So I went with the "obvious answer" above, which has no chance of
changing the behavior aside from fixing the leak.

With this patch, t1091 can now be marked leak-free.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-05 09:51:43 -07:00
Jeff King
a544b7da2c sparse-checkout: free string list after displaying
In sparse_checkout_list(), we put the hashmap entries into a string_list
so we can sort them. But after printing, we forget to free the list.

This patch drops 5 leaks from t1091.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-05 09:51:43 -07:00
Jeff King
521e04e6e8 sparse-checkout: free pattern list in sparse_checkout_list()
In sparse_checkout_list(), we create a pattern_list that needs to
eventually be cleared. We remember to do so in the regular code path,
but the cone-mode path does an early return, and forgets to clean up.

We could fix the leak by adding a new call to clear_pattern_list(). But
we can simplify even further by just skipping the early return, pushing
the other code path (which consists now of only one line!) into an else
block. That also matches the same cone/non-cone if/else used in some
other functions.

This fixes 15 leaks found in t1091.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-05 09:51:43 -07:00
Jeff King
008f59d2d6 sparse-checkout: free sparse_filename after use
We allocate a heap buffer via get_sparse_checkout_filename(). Most calls
remember to free it, but sparse_checkout_init() forgets to, causing a
leak. Ironically, it remembers to do so in the error return paths, but
not in the path that makes it all the way to the function end!

Fixing this clears up 6 leaks from t1091.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-05 09:51:43 -07:00
Jeff King
a14d49ca84 sparse-checkout: refactor temporary sparse_checkout_patterns
In update_working_directory(), we take in a pattern_list, attach it to
the repository index by assigning it to index->sparse_checkout_patterns,
and then call unpack_trees. Afterwards, we remove it by setting
index->sparse_checkout_patterns back to NULL.

But there are two possible leaks here:

  1. If the index already had a populated sparse_checkout_patterns,
     we've obliterated it. We can fix this by saving and restoring it,
     rather than always setting it back to NULL.

  2. We may call the function with a NULL pattern_list, expecting it to
     use the on-disk sparse file. In that case, the index routines will
     lazy-load the sparse patterns automatically. But now at the end of
     the function when we restore the patterns, we'll leak those
     lazy-loaded ones!

     We can fix this by freeing the pattern list before overwriting its
     pointer whenever it does not match what was passed in (in practice
     this should only happen when the passed-in list is NULL, but this
     is erring on the defensive side).

Together these remove 48 indirect leaks found in t1091.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-05 09:51:43 -07:00
Jeff King
d765fa0331 sparse-checkout: always free "line" strbuf after reading input
In add_patterns_from_input(), we may read lines from a file with a loop
like this:

  while (!strbuf_getline(&line, file)) {
	...
	strbuf_to_cone_pattern(&line, pl);
  }
  /* we don't strbuf_release(&line) here! */

This generally is OK because strbuf_to_cone_pattern() consumes the
buffer via strbuf_detach(). But we can leak in a few cases:

  1. We don't always consume the buffer! If the line ends up empty after
     trimming, we leave strbuf_to_cone_pattern() without detaching. In
     most cases this is OK, because a subsequent getline() call will use
     the same buffer. But if you had an empty line at the end of file,
     for example, it would leak.

  2. Even if strbuf_to_cone_pattern() always consumed the buffer,
     there's a subtle issue with strbuf_getline(). As we saw in
     94e2aa555e (strbuf: fix leak when `appendwholeline()` fails with
     EOF, 2024-05-27), it's possible for it to return EOF with an
     allocated buffer (e.g., if the underlying getdelim() call saw an
     error). So we should always strbuf_release() after finishing a read
     loop like this.

Note that even the code to read patterns from argv has the same problem.
Because that also uses strbuf_to_cone_pattern(), we stuff each argv
entry into a strbuf. It uses the same "line" strbuf as the getline code,
but we should position the strbuf_release() to cover both code paths.

This fixes at least 9 leaks found in t1091.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-05 09:51:43 -07:00
Jeff King
c3324649ed sparse-checkout: reuse --stdin buffer when reading patterns
When we read patterns from --stdin, we loop on strbuf_getline(), and
detach each line we read to pass into add_pattern(). This used to be
necessary because add_pattern() required that the pattern strings remain
valid while the pattern_list was in use. But it also created a leak,
since we didn't record the detached buffers anywhere else.

Now that add_pattern() has been modified to make its own copy of the
strings, we can stop detaching and fix the leak. This fixes 4 leaks
detected in t1091.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-05 09:51:42 -07:00
Jeff King
eed1fbe73b dir.c: always copy input to add_pattern()
The add_pattern() function has a subtle and undocumented gotcha: the
pattern string you pass in must remain valid as long as the pattern_list
is in use (and nor do we take ownership of it). This is easy to get
wrong, causing either subtle bugs (because you free or reuse the string
buffer) or leaks (because you copy the string, but don't track ownership
separately).

All of this "pattern" code was originally the "exclude" mechanism. So
this _usually_ works OK because you add entries in one of two ways:

  1. From the command-line (e.g., "--exclude"), in which case we're
     pointing to an argv entry which remains valid for the lifetime of
     the program.

  2. From a file (e.g., ".gitignore"), in which case we read the whole
     file into a buffer, attach it to the pattern_list's "filebuf"
     entry, then parse the buffer in-place (adding NULs). The strings
     point into the filebuf, which is cleaned up when the whole
     pattern_list goes away.

But other code, like sparse-checkout, reads individual lines from stdin
and passes them one by one to add_pattern(), leaking each. We could fix
this by refactoring it to take in the whole buffer at once, like (2)
above, and stuff it in "filebuf". But given how subtle the interface is,
let's just fix it to always copy the string.

That seems at first like we'd be wasting extra memory, but we can
mitigate that:

  a. The path_pattern struct already uses a FLEXPTR, since we sometimes
     make a copy (when we see "foo/", we strip off the trailing slash,
     requiring a modifiable copy of the string).

     Since we'll now always embed the string inside the struct, we can
     switch to the regular FLEX_ARRAY pattern, saving us 8 bytes of
     pointer. So patterns with a trailing slash and ones under 8 bytes
     actually get smaller.

  b. Now that we don't need the original string to hang around, we can
     get rid of the "filebuf" mechanism entirely, and just free the file
     contents after parsing. Since files are the sources we'd expect to
     have the largest pattern sets, we should mostly break even on
     stuffing the same data into the individual structs.

This patch just adjusts the add_pattern() interface; it doesn't fix any
leaky callers yet.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-05 09:51:42 -07:00
Jeff King
4c844c2f49 dir.c: free removed sparse-pattern hashmap entries
In add_pattern_to_hashsets(), we remove entries from the
recursive_hashmap when adding similar ones to the parent_hashmap. I
won't pretend to understand all of what's going on here, but there's an
obvious leak: whatever we removed from recursive_hashmap is not
referenced anywhere else, and is never free()d.

We can easily fix this by asking the hashmap to return a pointer to the
old entry. This makes t7002 now completely leak-free.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-04 10:38:23 -07:00
Jeff King
db83b64cda sparse-checkout: clear patterns when init() sees existing sparse file
In sparse_checkout_init(), we first try to load patterns from an
existing file. If we found any, we return immediately, but end up
leaking the patterns we parsed. Fixing this reduces the number of leaks
in t7002 from 9 down to 5.

Note that there are two other exits from the function, but they don't
need the same treatment:

  - if we can't resolve HEAD, we write out a hard-coded sparse file and
    return. But we know the pattern list is empty there, since we didn't
    find any in the on-disk file and we haven't yet added any of our
    own.

  - otherwise, we do populate the list and then tail-call into
    write_patterns_and_update(). But that function frees the
    pattern_list itself, so we don't need to.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-04 10:38:23 -07:00
Jeff King
4318d3ab65 dir.c: free strings in sparse cone pattern hashmaps
The pattern_list structs used for cone-mode sparse lookups use a few
extra hashmaps. These store pattern_entry structs, each of which has its
own heap-allocated pattern string. When we clean up the hashmaps, we
free the individual pattern_entry structs, but forget to clean up the
embedded strings, causing memory leaks.

We can fix this by iterating over the hashmaps to free the extra
strings. This reduces the numbers of leaks in t7002 from 22 to 9.

One alternative here would be to make the string a FLEX_ARRAY member of
the pattern_entry. Then there's no extra free() required, and as a bonus
it would be a little more efficient. However, some of the refactoring
gets awkward, as we are often assigning strings allocated by helper
functions. So let's just fix the leak for now, and we can explore bigger
refactoring separately.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-04 10:38:23 -07:00
Jeff King
4d7f95ed1f sparse-checkout: pass string literals directly to add_pattern()
The add_pattern() function takes a pattern string, but neither makes a
copy of it nor takes ownership of the memory. So it is the caller's
responsibility to make sure the string hangs around as long as the
pattern_list which references it.

There are a few cases in sparse-checkout where we use string literal
patterns by stuffing them into a strbuf, detaching the buffer, and then
passing the result into add_pattern(). This creates a leak when the
pattern_list is eventually cleared, since we don't retain a copy of the
detached buffer to free.

But we can observe that the whole strbuf dance is unnecessary. The point
was presumably[1] to satisfy the lifetime requirement of the string. But
string literals have static duration; we can count on them lasting for
the whole program.

So we can fix the leak by just passing them directly. And as a bonus,
that simplifies the code. The leaks can be seen in t7002, which drops
from 25 leaks to 22 with this patch. It also makes t3602 and t1090
leak-free.

In the long run, we will also want to clean up this (undocumented!)
memory lifetime requirement of add_pattern(). But that can come in a
later patch; passing the string literals directly will be the right
thing either way.

[1] The code in question comes from 416adc8711 (sparse-checkout: update
    working directory in-process for 'init', 2019-11-21) and 99dfa6f970
    (sparse-checkout: use in-process update for disable subcommand,
    2019-11-21), but I didn't see anything in their commit messages or
    on the list explaining the strbufs.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-04 10:38:23 -07:00
Jeff King
2181fe6e46 sparse-checkout: free string list in write_cone_to_file()
We use a string list to hold sorted and de-duped patterns, but don't
free it before leaving the function, causing a leak.

This drops the number of leaks found in t7002 from 27 to 25.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-04 10:38:22 -07:00
Junio C Hamano
94d25d3254 Merge branch 'jk/leakfixes' into jk/sparse-leakfix
* jk/leakfixes:
  mv: replace src_dir with a strvec
  mv: factor out empty src_dir removal
  mv: move src_dir cleanup to end of cmd_mv()
  t-strvec: mark variable-arg helper with LAST_ARG_MUST_BE_NULL
  t-strvec: use va_end() to match va_start()
2024-05-31 08:55:34 -07:00
Jeff King
64f8502b40 mv: replace src_dir with a strvec
We manually manage the src_dir array with ALLOC_GROW. Using a strvec is
a little more ergonomic, and makes the memory ownership more clear. It
does mean that we copy the strings (which were otherwise just pointers
into the "sources" strvec), but using the same rationale as 9fcd9e4e72
(builtin/mv duplicate string list memory, 2024-05-27), it's just not
enough to be worth worrying about here.

As a bonus, this gets rid of some "int"s used for allocation management
(though in practice these were limited to command-line sizes and thus
not overflowable).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-30 08:55:29 -07:00
Jeff King
d58a687705 mv: factor out empty src_dir removal
This pulls the loop added by b6f51e3db9 (mv: cleanup empty
WORKING_DIRECTORY, 2022-08-09) into a sub-function. That reduces clutter
in cmd_mv() and makes it easier to see that the lifetime of the
a_src_dir strbuf is limited to this code (and thus its cleanup doesn't
need to go after the "out" label).

Another option would be to just declare the strbuf inside the loop,
since it is only used there. But this refactor retains the existing
property that we can reuse the allocated buffer for each iteration of
the loop. That optimization is probably overkill, but I think the
sub-function is more readable anyway, and then keeping the optimization
is basically free.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-30 08:55:29 -07:00
Jeff King
cc65e085e4 mv: move src_dir cleanup to end of cmd_mv()
Commit b6f51e3db9 (mv: cleanup empty WORKING_DIRECTORY, 2022-08-09)
added an auxiliary array where we store directory arguments that we see
while processing the incoming arguments. After actually moving things,
we then use that array to remove now-empty directories, and then
immediately free the array.

But if the actual move queues any errors in only_match_skip_worktree,
that can cause us to jump straight to the "out" label to clean up,
skipping the free() and leaking the array.

Let's push the free() down past the "out" label so that we always clean
up (the array is initialized to NULL, so this is always safe). We'll
hold on to the memory a little longer than necessary, but clarity is
more important than micro-optimizing here.

Note that the adjacent "a_src_dir" strbuf does not suffer the same
problem; it is only allocated during the removal step.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-30 08:55:29 -07:00
Jeff King
34eb843721 t-strvec: mark variable-arg helper with LAST_ARG_MUST_BE_NULL
This will let the compiler catch a problem like:

  /* oops, we forgot the NULL */
  check_strvec(&vec, "foo");

rather than triggering undefined behavior at runtime.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-30 08:55:29 -07:00
Jeff King
b639884f9a t-strvec: use va_end() to match va_start()
Our check_strvec_loc() helper uses a variable argument list. When we
va_start(), we must be sure to va_end() before leaving the function.
This is required by the standard (though the effect of forgetting will
vary between platforms).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-30 08:55:29 -07:00
Junio C Hamano
a3f0e2a064 Merge branch 'ps/leakfixes' into jk/leakfixes
* ps/leakfixes:
  builtin/mv: fix leaks for submodule gitfile paths
  builtin/mv: refactor to use `struct strvec`
  builtin/mv duplicate string list memory
  builtin/mv: refactor `add_slash()` to always return allocated strings
  strvec: add functions to replace and remove strings
  submodule: fix leaking memory for submodule entries
  commit-reach: fix memory leak in `ahead_behind()`
  builtin/credential: clear credential before exit
  config: plug various memory leaks
  config: clarify memory ownership in `git_config_string()`
  builtin/log: stop using globals for format config
  builtin/log: stop using globals for log config
  convert: refactor code to clarify ownership of check_roundtrip_encoding
  diff: refactor code to clarify memory ownership of prefixes
  config: clarify memory ownership in `git_config_pathname()`
  http: refactor code to clarify memory ownership
  checkout: clarify memory ownership in `unique_tracking_name()`
  strbuf: fix leak when `appendwholeline()` fails with EOF
  transport-helper: fix leaking helper name
2024-05-30 08:54:58 -07:00
Junio C Hamano
3a57aa566a The eighth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-28 11:17:11 -07:00
Junio C Hamano
1a367763d0 Merge branch 'ps/leakfixes-base'
* ps/leakfixes-base:
  t: mark a bunch of tests as leak-free
  ci: add missing dependency for TTY prereq
2024-05-28 11:17:11 -07:00
Junio C Hamano
2a1a882890 Merge branch 'kn/osxkeychain-skip-idempotent-store'
The credential helper that talks with osx keychain learned to avoid
storing back the authentication material it just got received from
the keychain.

* kn/osxkeychain-skip-idempotent-store:
  osxkeychain: state to skip unnecessary store operations
  osxkeychain: exclusive lock to serialize execution of operations
2024-05-28 11:17:11 -07:00
Junio C Hamano
b32f298264 Merge branch 'jc/format-patch-more-aggressive-range-diff'
The default "creation-factor" used by "git format-patch" has been
raised to make it more aggressively find matching commits.

* jc/format-patch-more-aggressive-range-diff:
  format-patch: run range-diff with larger creation-factor
2024-05-28 11:17:10 -07:00
Junio C Hamano
3acecc04c7 Merge branch 'jc/rev-parse-fatal-doc'
Doc update.

* jc/rev-parse-fatal-doc:
  rev-parse: document how --is-* options work outside a repository
2024-05-28 11:17:10 -07:00
Junio C Hamano
dfe42162d9 Merge branch 'jc/t0017-clarify-bogus-expectation'
Test clean-up.

* jc/t0017-clarify-bogus-expectation:
  t0017: clarify dubious test set-up
2024-05-28 11:17:09 -07:00
Junio C Hamano
789ec1d91d Merge branch 'ds/send-email-per-message-block'
Preliminary code clean-up for "git send-email".

* ds/send-email-per-message-block:
  send-email: move newline characters out of a few translatable strings
2024-05-28 11:17:09 -07:00
Junio C Hamano
7a40196328 Merge branch 'ps/complete-config-w-subcommands'
The command line completion script (in contrib/) has been adjusted
to the recent update to "git config" that adopted subcommand based
UI.

* ps/complete-config-w-subcommands:
  completion: adapt git-config(1) to complete subcommands
2024-05-28 11:17:08 -07:00
Junio C Hamano
6e95dce712 Merge branch 'jc/doc-diff-name-only'
The documentation for "git diff --name-only" has been clarified
that it is about showing the names in the post-image tree.

* jc/doc-diff-name-only:
  diff: document what --name-only shows
2024-05-28 11:17:08 -07:00
Junio C Hamano
ee8537ebc9 Merge branch 'tb/pack-bitmap-write-cleanups'
The pack bitmap code saw some clean-up to prepare for a follow-up topic.

* tb/pack-bitmap-write-cleanups:
  pack-bitmap: introduce `bitmap_writer_free()`
  pack-bitmap-write.c: avoid uninitialized 'write_as' field
  pack-bitmap: drop unused `max_bitmaps` parameter
  pack-bitmap: avoid use of static `bitmap_writer`
  pack-bitmap-write.c: move commit_positions into commit_pos fields
  object.h: add flags allocated by pack-bitmap.h
2024-05-28 11:17:07 -07:00
Junio C Hamano
00ffa1cb1c Merge branch 'ps/builtin-config-cleanup'
Code clean-up to reduce inter-function communication inside
builtin/config.c done via the use of global variables.

* ps/builtin-config-cleanup: (21 commits)
  builtin/config: pass data between callbacks via local variables
  builtin/config: convert flags to a local variable
  builtin/config: track "fixed value" option via flags only
  builtin/config: convert `key` to a local variable
  builtin/config: convert `key_regexp` to a local variable
  builtin/config: convert `regexp` to a local variable
  builtin/config: convert `value_pattern` to a local variable
  builtin/config: convert `do_not_match` to a local variable
  builtin/config: move `respect_includes_opt` into location options
  builtin/config: move default value into display options
  builtin/config: move type options into display options
  builtin/config: move display options into local variables
  builtin/config: move location options into local variables
  builtin/config: refactor functions to have common exit paths
  config: make the config source const
  builtin/config: check for writeability after source is set up
  builtin/config: move actions into `cmd_config_actions()`
  builtin/config: move legacy options into `cmd_config()`
  builtin/config: move subcommand options into `cmd_config()`
  builtin/config: move legacy mode into its own function
  ...
2024-05-28 11:17:07 -07:00
Junio C Hamano
16a592f132 Merge branch 'ps/pseudo-ref-terminology'
Terminology to call various ref-like things are getting
straightened out.

* ps/pseudo-ref-terminology:
  refs: refuse to write pseudorefs
  ref-filter: properly distinuish pseudo and root refs
  refs: pseudorefs are no refs
  refs: classify HEAD as a root ref
  refs: do not check ref existence in `is_root_ref()`
  refs: rename `is_special_ref()` to `is_pseudo_ref()`
  refs: rename `is_pseudoref()` to `is_root_ref()`
  Documentation/glossary: define root refs as refs
  Documentation/glossary: clarify limitations of pseudorefs
  Documentation/glossary: redefine pseudorefs as special refs
2024-05-28 11:17:06 -07:00
Junio C Hamano
3b1e3f02bf Merge branch 'kn/patch-iteration-doc'
Doc updates.

* kn/patch-iteration-doc:
  SubmittingPatches: add section for iterating patches
2024-05-28 11:17:06 -07:00
Junio C Hamano
eeec143a37 Merge branch 'mt/t0211-typofix'
Test fix.

* mt/t0211-typofix:
  t/t0211-trace2-perf.sh: fix typo patern -> pattern
2024-05-28 11:17:05 -07:00
Junio C Hamano
64a7424694 Merge branch 'jc/doc-manpages-l10n'
The SubmittingPatches document now refers folks to manpages
translation project.

* jc/doc-manpages-l10n:
  SubmittingPatches: advertise git-manpages-l10n project a bit
2024-05-28 11:17:05 -07:00
Patrick Steinhardt
ebdbefa4fe builtin/mv: fix leaks for submodule gitfile paths
Similar to the preceding commit, we have effectively given tracking
memory ownership of submodule gitfile paths. Refactor the code to start
tracking allocated strings in a separate `struct strvec` such that we
can easily plug those leaks. Mark now-passing tests as leak free.

Note that ideally, we wouldn't require two separate data structures to
track those paths. But we do need to store `NULL` pointers for the
gitfile paths such that we can indicate that its corresponding entries
in the other arrays do not have such a path at all. And given that
`struct strvec`s cannot store `NULL` pointers we cannot use them to
store this information.

There is another small gotcha that is easy to miss: you may be wondering
why we don't want to store `SUBMODULE_WITH_GITDIR` in the strvec. This
is because this is a mere sentinel value and not actually a string at
all.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:20:03 -07:00
Patrick Steinhardt
52a7dab439 builtin/mv: refactor to use struct strvec
Memory allocation patterns in git-mv(1) are extremely hard to follow:
We copy around string pointers into manually-managed arrays, some of
which alias each other, but only sometimes, while we also drop some of
those strings at other times without ever daring to free them.

While this may be my own subjective feeling, it seems like others have
given up as the code has multiple calls to `UNLEAK()`. These are not
sufficient though, and git-mv(1) is still leaking all over the place
even with them.

Refactor the code to instead track strings in `struct strvec`. While
this has the effect of effectively duplicating some of the strings
without an actual need, it is way easier to reason about and fixes all
of the aliasing of memory that has been going on. It allows us to get
rid of the `UNLEAK()` calls and also fixes leaks that those calls did
not paper over.

Mark tests which are now leak-free accordingly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:20:02 -07:00
Patrick Steinhardt
9fcd9e4e72 builtin/mv duplicate string list memory
makes the next patch easier, where we will migrate to the paths being
owned by a strvec. given that we are talking about command line
parameters here it's also not like we have tons of allocations that this
would save

while at it, fix a memory leak

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:20:02 -07:00
Patrick Steinhardt
3d231f7b82 builtin/mv: refactor add_slash() to always return allocated strings
The `add_slash()` function will only conditionally return an allocated
string when the passed-in string did not yet have a trailing slash. This
makes the memory ownership harder to track than really necessary.

It's dubious whether this optimization really buys us all that much. The
number of times we execute this function is bounded by the number of
arguments to git-mv(1), so in the typical case we may end up saving an
allocation or two.

Simplify the code to unconditionally return allocated strings.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:20:02 -07:00
Patrick Steinhardt
11ce77b5cc strvec: add functions to replace and remove strings
Add two functions that allow to replace and remove strings contained in
the strvec. This will be used by a subsequent commit that refactors
git-mv(1).

While at it, add a bunch of unit tests that cover both old and new
functionality.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:20:02 -07:00
Patrick Steinhardt
3ef52dd112 submodule: fix leaking memory for submodule entries
In `free_one_config()` we never end up freeing the `url` and `ignore`
fields and thus leak memory. Fix those leaks and mark now-passing tests
as leak free.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:20:01 -07:00
Patrick Steinhardt
ba9d029445 commit-reach: fix memory leak in ahead_behind()
We use a priority queue in `ahead_behind()` to compute the ahead/behind
count for commits. We may not iterate through all commits part of that
queue though in case all of its entries are stale. Consequently, as we
never make the effort to release the remaining commits, we end up
leaking bit arrays that we have allocated for each of the contained
commits.

Plug this leak and mark the corresponding test as leak free.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:20:01 -07:00
Patrick Steinhardt
96c1655095 builtin/credential: clear credential before exit
We never release memory associated with `struct credential`. Fix this
and mark the corresponding test as leak free.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:20:01 -07:00
Patrick Steinhardt
49eb597ce0 config: plug various memory leaks
Now that memory ownership rules around `git_config_string()` and
`git_config_pathname()` are clearer, it also got easier to spot that
the returned memory needs to be free'd. Plug a subset of those cases and
mark now-passing tests as leak free.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:20:00 -07:00
Patrick Steinhardt
1b261c20ed config: clarify memory ownership in git_config_string()
The out parameter of `git_config_string()` is a `const char **` even
though we transfer ownership of memory to the caller. This is quite
misleading and has led to many memory leaks all over the place. Adapt
the parameter to instead be `char **`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:20:00 -07:00
Patrick Steinhardt
83024d98f7 builtin/log: stop using globals for format config
This commit does the exact same as the preceding commit, only for the
format configuration instead of the log configuration.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:20:00 -07:00
Patrick Steinhardt
106a54aecb builtin/log: stop using globals for log config
We're using global variables to store the log configuration. Many of
these can be set both via the command line and via the config, and
depending on how they are being set, they may contain allocated strings.
This leads to hard-to-track memory ownership and memory leaks.

Refactor the code to instead use a `struct log_config` that is being
allocated on the stack. This allows us to more clearly scope the
variables, track memory ownership and ultimately release the memory.

This also prepares us for a change to `git_config_string()`, which will
be adapted to have a `char **` out parameter instead of `const char **`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:19:59 -07:00
Patrick Steinhardt
a6cb0cc610 convert: refactor code to clarify ownership of check_roundtrip_encoding
The `check_roundtrip_encoding` variable is tracked in a `const char *`
even though it may contain allocated strings at times. The result is
that those strings may be leaking because we never free them.

Refactor the code to always store allocated strings in this variable.
The default value is handled in `check_roundtrip()` now, which is the
only user of the variable.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:19:59 -07:00
Patrick Steinhardt
f9c1989674 diff: refactor code to clarify memory ownership of prefixes
The source and destination prefixes are tracked in a `const char *`
array, but may at times contain allocated strings. The result is that
those strings may be leaking because we never free them.

Refactor the code to always store allocated strings in those variables,
freeing them as required. This requires us to handle the default values
a bit different compared to before. But given that there is only a
single callsite where we use the variables to `struct diff_options` it's
easy to handle the defaults there.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:19:59 -07:00
Patrick Steinhardt
6073b3b5c3 config: clarify memory ownership in git_config_pathname()
The out parameter of `git_config_pathname()` is a `const char **` even
though we transfer ownership of memory to the caller. This is quite
misleading and has led to many memory leaks all over the place. Adapt
the parameter to instead be `char **`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:19:59 -07:00