Commit Graph

91 Commits

Author SHA1 Message Date
Patrick Steinhardt
f59aa5e0a9 builtin: stop using the_index
Convert builtins to use `the_repository->index` instead of `the_index`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-18 12:30:42 -07:00
Junio C Hamano
d842e22ebb Merge branch 'js/merge-tree-3-trees'
Match the option argument type in the help text to the correct type
updated by a recent series.

* js/merge-tree-3-trees:
  merge-tree: fix argument type of the `--merge-base` option
2024-04-12 11:31:38 -07:00
Johannes Schindelin
0c6ee971fb merge-tree: fix argument type of the --merge-base option
In 5f43cf5b2e (merge-tree: accept 3 trees as arguments, 2024-01-28), I
taught `git merge-tree` to perform three-way merges on trees. This
commit even changed the manual page to state that the `--merge-base`
option takes a tree-ish rather than requiring a commit.

But I forgot to adjust the in-program help text. This patch fixes that.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-04-12 09:10:43 -07:00
Junio C Hamano
7745f92507 Merge branch 'js/merge-base-with-missing-commit'
Make sure failure return from merge_bases_many() is properly caught.

* js/merge-base-with-missing-commit:
  merge-ort/merge-recursive: do report errors in `merge_submodule()`
  merge-recursive: prepare for `merge_submodule()` to report errors
  commit-reach(repo_get_merge_bases_many_dirty): pass on errors
  commit-reach(repo_get_merge_bases_many): pass on "missing commits" errors
  commit-reach(get_octopus_merge_bases): pass on "missing commits" errors
  commit-reach(repo_get_merge_bases): pass on "missing commits" errors
  commit-reach(get_merge_bases_many_0): pass on "missing commits" errors
  commit-reach(merge_bases_many): pass on "missing commits" errors
  commit-reach(paint_down_to_common): start reporting errors
  commit-reach(paint_down_to_common): prepare for handling shallow commits
  commit-reach(repo_in_merge_bases_many): report missing commits
  commit-reach(repo_in_merge_bases_many): optionally expect missing commits
  commit-reach(paint_down_to_common): plug two memory leaks
2024-03-11 14:12:30 -07:00
Junio C Hamano
ae46d5fb98 Merge branch 'js/merge-tree-3-trees'
"git merge-tree" has learned that the three trees involved in the
3-way merge only need to be trees, not necessarily commits.

* js/merge-tree-3-trees:
  fill_tree_descriptor(): mark error message for translation
  cache-tree: avoid an unnecessary check
  Always check `parse_tree*()`'s return value
  t4301: verify that merge-tree fails on missing blob objects
  merge-ort: do check `parse_tree()`'s return value
  merge-tree: fail with a non-zero exit code on missing tree objects
  merge-tree: accept 3 trees as arguments
2024-03-07 15:59:41 -08:00
Johannes Schindelin
76e2a09999 commit-reach(repo_get_merge_bases): pass on "missing commits" errors
The `merge_bases_many()` function was just taught to indicate parsing
errors, and now the `repo_get_merge_bases()` function (which is also
surfaced via the `repo_get_merge_bases()` macro) is aware of that, too.

Naturally, there are a lot of callers that need to be adjusted now, too.

Next step: adjust the callers of `get_octopus_merge_bases()`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-29 08:06:01 -08:00
Johannes Schindelin
aa9f618909 Always check parse_tree*()'s return value
Otherwise we may easily run into serious crashes: For example, if we run
`init_tree_desc()` directly after a failed `parse_tree()`, we are
accessing uninitialized data or trying to dereference `NULL`.

Note that the `parse_tree()` function already takes care of showing an
error message. The `parse_tree_indirectly()` and
`repo_get_commit_tree()` functions do not, therefore those latter call
sites need to show a useful error message while the former do not.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-23 10:19:40 -08:00
Johannes Schindelin
5f43cf5b2e merge-tree: accept 3 trees as arguments
When specifying a merge base explicitly, there is actually no good
reason why the inputs need to be commits: that's only needed if the
merge base has to be deduced from the commit graph.

This commit is best viewed with `--color-moved
--color-moved-ws=allow-indentation-change`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-29 09:20:49 -08:00
Junio C Hamano
492ee03f60 Merge branch 'en/header-cleanup'
Remove unused header "#include".

* en/header-cleanup:
  treewide: remove unnecessary includes in source files
  treewide: add direct includes currently only pulled in transitively
  trace2/tr2_tls.h: remove unnecessary include
  submodule-config.h: remove unnecessary include
  pkt-line.h: remove unnecessary include
  line-log.h: remove unnecessary include
  http.h: remove unnecessary include
  fsmonitor--daemon.h: remove unnecessary includes
  blame.h: remove unnecessary includes
  archive.h: remove unnecessary include
  treewide: remove unnecessary includes in source files
  treewide: remove unnecessary includes from header files
2024-01-08 14:05:15 -08:00
Elijah Newren
eea0e59ffb treewide: remove unnecessary includes in source files
Each of these were checked with
   gcc -E -I. ${SOURCE_FILE} | grep ${HEADER_FILE}
to ensure that removing the direct inclusion of the header actually
resulted in that header no longer being included at all (i.e. that
no other header pulled it in transitively).

...except for a few cases where we verified that although the header
was brought in transitively, nothing from it was directly used in
that source file.  These cases were:
  * builtin/credential-cache.c
  * builtin/pull.c
  * builtin/send-pack.c

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-26 12:04:31 -08:00
René Scharfe
7854bf4960 i18n: factorize even more 'incompatible options' messages
Continue the work of 12909b6b8a (i18n: turn "options are incompatible"
into "cannot be used together", 2022-01-05) and a699367bb8 (i18n:
factorize more 'incompatible options' messages, 2022-01-31) to use the
same parameterized error message for reporting incompatible command line
options.  This reduces the number of strings to translate and makes the
UI slightly more consistent.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-27 10:01:45 +09:00
Junio C Hamano
b182658e3e merge: introduce {copy|clear}_merge_options()
When mostly the same set of options are to be used to perform
multiple merges, one instance of the merge_options structure may
want to be created and used by copying from the same template
instance.  We saw such a use recently in "git merge-tree".

Let's make the pattern official by introducing copy_merge_options()
as a supported way to make a copy of the structure, and also give
clear_merge_options() to release any resources held by a copied
instance.  Currently we only make a shallow copy, so the former is a
mere structure assignment while the latter is a no-op, but this may
change in the future as the members of merge_options structure
evolve.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-11 13:37:47 -07:00
Tang Yuyi
6a4c9e7b32 merge-tree: add -X strategy option
Add merge strategy option to produce more customizable merge result such
as automatically resolving conflicts.

Signed-off-by: Tang Yuyi <winglovet@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-09-25 14:37:42 -07:00
Jeff King
ee550abcce merge-tree: mark unused parameter in traverse callback
Our threeway_callback() does not bother to look at its "n" parameter. It
is static in this file and used only by trivial_merge_trees(), which
always passes 3 trees (hence the name "threeway"). It also does not look
at "dirmask". This is OK, as it handles directories specifically by
looking at the mode bits.

Other traverse_info callbacks need these, so we can't get drop them from
the interface. But let's annotate these ones to avoid complaints from
-Wunused-parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-13 17:24:00 -07:00
Elijah Newren
a034e9106f object-store-ll.h: split this header out of object-store.h
The vast majority of files including object-store.h did not need dir.h
nor khash.h.  Split the header into two files, and let most just depend
upon object-store-ll.h, while letting the two callers that need it
depend on the full object-store.h.

After this patch:
    $ git grep -h include..object-store | sort | uniq -c
          2 #include "object-store.h"
        129 #include "object-store-ll.h"

Diff best viewed with `--color-moved`.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-21 13:39:54 -07:00
Teng Long
e4cf013468 surround %s with quotes when failed to lookup commit
The output may become confusing to recognize if the user
accidentally gave an extra opening space, like:

   $ git commit --fixup=" 6d6360b67e99c2fd82d64619c971fdede98ee74b"
   fatal: could not lookup commit  6d6360b67e99c2fd82d64619c971fdede98ee74b

and it will be better if we surround the %s specifier with single quotes.

Signed-off-by: Teng Long <dyroneteng@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-03 09:01:10 +09:00
Junio C Hamano
80754c5cc0 Merge branch 'ds/merge-tree-use-config'
Allow git forges to disable replace-refs feature while running "git
merge-tree".

* ds/merge-tree-use-config:
  merge-tree: load default git config
2023-05-15 13:59:06 -07:00
Derrick Stolee
b6551feadf merge-tree: load default git config
The 'git merge-tree' command handles creating root trees for merges
without using the worktree. This is a critical operation in many Git
hosts, as they typically store bare repositories.

This builtin does not load the default Git config, which can have
several important ramifications.

In particular, one config that is loaded by default is
core.useReplaceRefs. This is typically disabled in Git hosts due to
the ability to spoof commits in strange ways.

Since this config is not loaded specifically during merge-tree, users
were previously able to use refs/replace/ references to make pull
requests that looked valid but introduced malicious content. The
resulting merge commit would have the correct commit history, but the
malicious content would exist in the root tree of the merge.

The fix is simple: load the default Git config in cmd_merge_tree().
This may also fix other behaviors that are effected by reading default
config. The only possible downside is a little extra computation time
spent reading config. The config parsing is placed after basic argument
parsing so it does not slow down usage errors.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-10 12:20:44 -07:00
Elijah Newren
d4a4f9291d commit.h: reduce unnecessary includes
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-24 12:47:33 -07:00
Elijah Newren
dabab1d6e6 object-name.h: move declarations for object-name.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-11 08:52:09 -07:00
Junio C Hamano
e7dca80692 Merge branch 'ab/remove-implicit-use-of-the-repository' into en/header-split-cache-h
* ab/remove-implicit-use-of-the-repository:
  libs: use "struct repository *" argument, not "the_repository"
  post-cocci: adjust comments for recent repo_* migration
  cocci: apply the "revision.h" part of "the_repository.pending"
  cocci: apply the "rerere.h" part of "the_repository.pending"
  cocci: apply the "refs.h" part of "the_repository.pending"
  cocci: apply the "promisor-remote.h" part of "the_repository.pending"
  cocci: apply the "packfile.h" part of "the_repository.pending"
  cocci: apply the "pretty.h" part of "the_repository.pending"
  cocci: apply the "object-store.h" part of "the_repository.pending"
  cocci: apply the "diff.h" part of "the_repository.pending"
  cocci: apply the "commit.h" part of "the_repository.pending"
  cocci: apply the "commit-reach.h" part of "the_repository.pending"
  cocci: apply the "cache.h" part of "the_repository.pending"
  cocci: add missing "the_repository" macros to "pending"
  cocci: sort "the_repository" rules by header
  cocci: fix incorrect & verbose "the_repository" rules
  cocci: remove dead rule from "the_repository.pending.cocci"
2023-04-04 08:25:52 -07:00
Ævar Arnfjörð Bjarmason
bc726bd075 cocci: apply the "object-store.h" part of "the_repository.pending"
Apply the part of "the_repository.pending.cocci" pertaining to
"object-store.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:45 -07:00
Ævar Arnfjörð Bjarmason
ecb5091fd4 cocci: apply the "commit.h" part of "the_repository.pending"
Apply the part of "the_repository.pending.cocci" pertaining to
"commit.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:45 -07:00
Ævar Arnfjörð Bjarmason
cb338c23d6 cocci: apply the "commit-reach.h" part of "the_repository.pending"
Apply the part of "the_repository.pending.cocci" pertaining to
"commit-reach.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:36 -07:00
Elijah Newren
f394e093df treewide: be explicit about dependence on gettext.h
Dozens of files made use of gettext functions, without explicitly
including gettext.h.  This made it more difficult to find which files
could remove a dependence on cache.h.  Make C files explicitly include
gettext.h if they are using it.

However, while compat/fsmonitor/fsm-ipc-darwin.c should also gain an
include of gettext.h, it was left out to avoid conflicting with an
in-flight topic.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:51 -07:00
Elijah Newren
41771fa435 cache.h: remove dependence on hex.h; make other files include it explicitly
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:29 -08:00
Junio C Hamano
179547932f Merge branch 'jk/unused-post-2.39'
Code clean-up around unused function parameters.

* jk/unused-post-2.39:
  userdiff: mark unused parameter in internal callback
  list-objects-filter: mark unused parameters in virtual functions
  diff: mark unused parameters in callbacks
  xdiff: mark unused parameter in xdl_call_hunk_func()
  xdiff: drop unused parameter in def_ff()
  ws: drop unused parameter from ws_blank_line()
  list-objects: drop process_gitlink() function
  blob: drop unused parts of parse_blob_buffer()
  ls-refs: use repository parameter to iterate refs
2022-12-26 11:42:05 +09:00
Junio C Hamano
7576e512ce Merge branch 'kz/merge-tree-merge-base'
"merge-tree" learns a new `--merge-base` option.

* kz/merge-tree-merge-base:
  docs: fix description of the `--merge-base` option
  merge-tree.c: allow specifying the merge-base when --stdin is passed
  merge-tree.c: add --merge-base=<commit> option
2022-12-14 15:55:46 +09:00
Jeff King
61bdc7c5d8 diff: mark unused parameters in callbacks
The diff code provides a format_callback interface, but not every
callback needs each parameter (e.g., the "opt" and "data" parameters are
frequently left unused). Likewise for the output_prefix callback, the
low-level change/add_remove interfaces, the callbacks used by
xdi_diff(), etc.

Mark unused arguments in the callback implementations to quiet
-Wunused-parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-13 22:16:23 +09:00
Ævar Arnfjörð Bjarmason
666f53eb43 {builtin/*,repository}.c: add & use "USE_THE_INDEX_VARIABLE"
Split up the "USE_THE_INDEX_COMPATIBILITY_MACROS" into that setting
and a more narrow "USE_THE_INDEX_VARIABLE". In the case of these
built-ins we only need "the_index" variable, but not the compatibility
wrapper for functions we're not using.

Let's then have some users of "USE_THE_INDEX_COMPATIBILITY_MACROS" use
this more narrow and descriptive define.

For context: The USE_THE_INDEX_COMPATIBILITY_MACROS macro was added to
test-tool.h in f8adbec9fe (cache.h: flip
NO_THE_INDEX_COMPATIBILITY_MACROS switch, 2019-01-24).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-11-21 12:06:15 +09:00
Kyle Zhao
501e3bab99 merge-tree.c: allow specifying the merge-base when --stdin is passed
The previous commit added a `--merge-base` option in order to allow
using a specified merge-base for the merge.  Extend the input accepted
by `--stdin` to also allow a specified merge-base with each merge
requested.  For example:

    printf "<b3> -- <b1> <b2>" | git merge-tree --stdin

does a merge of b1 and b2, and uses b3 as the merge-base.

Signed-off-by: Kyle Zhao <kylezhao@tencent.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-11-12 23:53:04 -05:00
Kyle Zhao
66265a693e merge-tree.c: add --merge-base=<commit> option
This patch will give our callers more flexibility to use `git merge-tree`,
such as:

    git merge-tree --write-tree --merge-base=branch^ HEAD branch

This does a merge of HEAD and branch, but uses branch^ as the merge-base.

And the reason why using an option flag instead of a positional argument
is to allow additional commits passed to merge-tree to be handled via an
octopus merge in the future.

Signed-off-by: Kyle Zhao <kylezhao@tencent.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-11-12 23:53:04 -05:00
Elijah Newren
ec1edbcb56 merge-tree: support multiple batched merges with --stdin
Add an option, --stdin, to merge-tree which will accept lines of input
with two branches to merge per line, and which will perform all the
merges and give output for each in turn.  This option implies -z, and
modifies the output to also include a merge status since the exit code
of the program can no longer convey that information now that multiple
merges are involved.

This could be useful, for example, by Git hosting providers.  When one
branch is updated, one may want to check whether all code reviews
targetting that branch can still cleanly merge.  Avoiding the overhead
of starting up a separate process for each of those code reviews might
provide significant savings in a repository with many code reviews.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-22 22:21:26 -07:00
Elijah Newren
7976721d17 merge-tree: add a --allow-unrelated-histories flag
Folks may want to merge histories that have no common ancestry; provide
a flag with the same name as used by `git merge` to allow this.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22 16:10:06 -07:00
Elijah Newren
7c48b27822 merge-tree: allow ls-files -u style info to be NUL terminated
Much as `git ls-files` has a -z option, let's add one to merge-tree so
that the conflict-info section can be NUL terminated (and avoid quoting
of unusual filenames).

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22 16:10:06 -07:00
Elijah Newren
de90581141 merge-ort: optionally produce machine-readable output
With the new `detailed` parameter, a new mode can be triggered when
displaying the merge messages: The `detailed` mode prints NUL-delimited
fields of the following form:

	<path-count> NUL <path>... NUL <conflict-type> NUL <message>

The `<path-count>` field determines how many `<path>` fields there are.

The intention of this mode is to support server-side operations, where
worktree-less merges can lead to conflicts and depending on the type
and/or path count, the caller might know how to handle said conflict.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22 16:10:06 -07:00
Elijah Newren
b520bc6caa merge-tree: provide easy access to ls-files -u style info
Much like `git merge` updates the index with information of the form
    (mode, oid, stage, name)
provide this output for conflicted files for merge-tree as well.
Provide a --name-only option for users to exclude the mode, oid, and
stage and only get the list of conflicted filenames.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22 16:10:06 -07:00
Elijah Newren
7fa3338870 merge-tree: provide a list of which files have conflicts
Callers of `git merge-tree --write-tree` will often want to know which
files had conflicts.  While they could potentially attempt to parse the
CONFLICT notices printed, those messages are not meant to be machine
readable.  Provide a simpler mechanism of just printing the files (in
the same format as `git ls-files` with quoting, but restricted to
unmerged files) in the output before the free-form messages.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22 16:10:06 -07:00
Elijah Newren
a1a7811975 merge-tree: support including merge messages in output
When running `git merge-tree --write-tree`, we previously would only
return an exit status reflecting the cleanness of a merge, and print out
the toplevel tree of the resulting merge.  Merges also have
informational messages, such as:
  * "Auto-merging <PATH>"
  * "CONFLICT (content): ..."
  * "CONFLICT (file/directory)"
  * etc.
In fact, when non-content conflicts occur (such as file/directory,
modify/delete, add/add with differing modes, rename/rename (1to2),
etc.), these informational messages may be the only notification the
user gets since these conflicts are not representable in the contents
of the file.

Add a --[no-]messages option so that callers can request these messages
be included at the end of the output.  Include such messages by default
when there are conflicts, and omit them by default when the merge is
clean.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22 16:10:06 -07:00
Elijah Newren
1f0c3a29da merge-tree: implement real merges
This adds the ability to perform real merges rather than just trivial
merges (meaning handling three way content merges, recursive ancestor
consolidation, renames, proper directory/file conflict handling, and so
forth).  However, unlike `git merge`, the working tree and index are
left alone and no branch is updated.

The only output is:
  - the toplevel resulting tree printed on stdout
  - exit status of 0 (clean), 1 (conflicts present), anything else
    (merge could not be performed; unknown if clean or conflicted)

This output is meant to be used by some higher level script, perhaps in
a sequence of steps like this:

   NEWTREE=$(git merge-tree --write-tree $BRANCH1 $BRANCH2)
   test $? -eq 0 || die "There were conflicts..."
   NEWCOMMIT=$(git commit-tree $NEWTREE -p $BRANCH1 -p $BRANCH2)
   git update-ref $BRANCH1 $NEWCOMMIT

Note that higher level scripts may also want to access the
conflict/warning messages normally output during a merge, or have quick
access to a list of files with conflicts.  That is not available in this
preliminary implementation, but subsequent commits will add that
ability (meaning that NEWTREE would be a lot more than a tree in the
case of conflicts).

This also marks the traditional trivial merge of merge-tree as
deprecated.  The trivial merge not only had limited applicability, the
output format was also difficult to work with (and its format
undocumented), and will generally be less performant than real merges.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22 16:10:05 -07:00
Elijah Newren
6ec755a0e1 merge-tree: add option parsing and initial shell for real merge function
Let merge-tree accept a `--write-tree` parameter for choosing real
merges instead of trivial merges, and accept an optional
`--trivial-merge` option to get the traditional behavior.  Note that
these accept different numbers of arguments, though, so these names
need not actually be used.

Note that real merges differ from trivial merges in that they handle:
  - three way content merges
  - recursive ancestor consolidation
  - renames
  - proper directory/file conflict handling
  - etc.
Basically all the stuff you'd expect from `git merge`, just without
updating the index and working tree.  The initial shell added here does
nothing more than die with "real merges are not yet implemented", but
that will be fixed in subsequent commits.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22 16:10:05 -07:00
Elijah Newren
55e48f6bf7 merge-tree: move logic for existing merge into new function
In preparation for adding a non-trivial merge capability to merge-tree,
move the existing merge logic for trivial merges into a new function.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22 16:10:05 -07:00
Elijah Newren
70176b7015 merge-tree: rename merge_trees() to trivial_merge_trees()
merge-recursive.h defined its own merge_trees() function, different than
the one found in builtin/merge-tree.c.  That was okay in the past, but
we want merge-tree to be able to use the merge-ort functions, which will
end up including merge-recursive.h.  Rename the function found in
builtin/merge-tree.c to avoid the conflict.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-22 16:10:05 -07:00
Ævar Arnfjörð Bjarmason
22233d43eb xdiff users: use designated initializers for out_line
Amend the code added in 611e42a598 (xdiff: provide a separate emit
callback for hunks, 2018-11-02) to be more readable by using
designated initializers.

This changes "priv" in rerere.c to be initialized to NULL as we did in
merge-tree.c. That's not needed as we'll only use it if the callback
is defined, but being consistent here is better and less verbose.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-11 12:47:31 +09:00
Michał Kępień
ec7967cfaf merge-base, xdiff: zero out xpparam_t structures
xpparam_t structures are usually zero-initialized before their specific
fields are assigned to, but there are three locations in the tree where
that does not happen.  Add the missing memset() calls in order to make
initialization of xpparam_t structures consistent tree-wide and to
prevent stack garbage from being used as field values.

Signed-off-by: Michał Kępień <michal@isc.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-20 12:53:26 -07:00
Junio C Hamano
1b01cdbf2e Merge branch 'jk/tree-walk-overflow'
Codepaths to walk tree objects have been audited for integer
overflows and hardened.

* jk/tree-walk-overflow:
  tree-walk: harden make_traverse_path() length computations
  tree-walk: add a strbuf wrapper for make_traverse_path()
  tree-walk: accept a raw length for traverse_path_len()
  tree-walk: use size_t consistently
  tree-walk: drop oid from traverse_info
  setup_traverse_info(): stop copying oid
2019-08-22 12:34:10 -07:00
Jeff King
c43ab06259 tree-walk: add a strbuf wrapper for make_traverse_path()
All but one of the callers of make_traverse_path() allocate a new heap
buffer to store the path. Let's give them an easy way to write to a
strbuf, which saves them from computing the length themselves (which is
especially tricky when they want to add to the path). It will also make
it easier for us to change the make_traverse_path() interface in a
future patch to improve its bounds-checking.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-01 13:06:52 -07:00
Jeff King
b3b3cbcbf2 tree-walk: accept a raw length for traverse_path_len()
We take a "struct name_entry", but only care about the length of the
path name. Let's just take that length directly, making it easier to use
the function from callers that sometimes do not have a name_entry at
all.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-01 13:06:52 -07:00
Jeff King
9055384710 tree-walk: drop oid from traverse_info
As the previous commit shows, the presence of an oid in each level of
the traverse_info is confusing and ultimately not necessary. Let's drop
it to make it clear that it will not always be set (as well as convince
us that it's unused, and let the compiler catch any merges with other
branches that do add new uses).

Since the oid is part of name_entry, we'll actually stop embedding a
name_entry entirely, and instead just separately hold the pathname, its
length, and the mode.

This makes the resulting code slightly more verbose as we have to pass
those elements around individually. But it also makes it more clear what
each code path is going to use (and in most of the paths, we really only
care about the pathname itself).

A few of these conversions are noisier than they need to be, as they
also take the opportunity to rename "len" to "namelen" for clarity
(especially where we also have "pathlen" or "ce_len" alongside).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-31 13:34:25 -07:00
Jeff King
947208b725 setup_traverse_info(): stop copying oid
We assume that if setup_traverse_info() is passed a non-empty "base"
string, that string is pointing into a tree object and we can read the
object oid by skipping past the trailing NUL.

As it turns out, this is not true for either of the two calls, and we
may end up reading garbage bytes:

  1. In git-merge-tree, our base string is either empty (in which case
     we'd never run this code), or it comes from our traverse_path()
     helper. The latter overallocates a buffer by the_hash_algo->rawsz
     bytes, but then fills it with only make_traverse_path(), leaving
     those extra bytes uninitialized (but part of a legitimate heap
     buffer).

  2. In unpack_trees(), we pass o->prefix, which is some arbitrary
     string from the caller. In "git read-tree --prefix=foo", for
     instance, it will point to the command-line parameter, and we'll
     read 20 bytes past the end of the string.

Interestingly, tools like ASan do not detect (2) because the process
argv is part of a big pre-allocated buffer. So we're reading trash, but
it's trash that's probably part of the next argument, or the
environment.

You can convince it to fail by putting something like this at the
beginning of common-main.c's main() function:

  {
	int i;
	for (i = 0; i < argc; i++)
		argv[i] = xstrdup_or_null(argv[i]);
  }

That puts the arguments into their own heap buffers, so running:

  make SANITIZE=address test

will find problems when "read-tree --prefix" is used (e.g., in t3030).

Doubly interesting, even with the hackery above, this does not fail
prior to ea82b2a085 (tree-walk: store object_id in a separate member,
2019-01-15). That commit switched setup_traverse_info() to actually
copying the hash, rather than simply pointing to it. That pointer was
always pointing to garbage memory, but that commit started actually
dereferencing the bytes, which is what triggers ASan.

That also implies that nobody actually cares about reading these oid
bytes anyway (or at least no path covered by our tests). And manual
inspection of the code backs that up (I'll follow this patch with some
cleanups that show definitively this is the case, but they're quite
invasive, so it's worth doing this fix on its own).

So let's drop the bogus hashcpy(), along with the confusing oversizing
in merge-tree.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-31 13:30:58 -07:00