Since some callers may want to send warning messages to somewhere other
than stdout/stderr, stop printing "warning: Cannot merge binary files"
from ll-merge and instead modify the return status of ll_merge() to
indicate when a merge of binary files has occurred. Message printing
probably does not belong in a "low-level merge" anyway.
This commit continues printing the message as-is, just from the callers
instead of within ll_merge(). Future changes will start handling the
message differently in the merge-ort codepath.
There was one special case here: the callers in rerere.c do NOT check
for and print such a message; since those code paths explicitly skip
over binary files, there is no reason to check for a return status of
LL_MERGE_BINARY_CONFLICT or print the related message.
Note that my methodology included first modifying ll_merge() to return
a struct, so that the compiler would catch all the callers for me and
ensure I had modified all of them. After modifying all of them, I then
changed the struct to an enum.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Follow through the work to use the repo interface to access
submodule objects in-process, instead of abusing the alternate
object database interface.
* jt/no-abuse-alternate-odb-for-submodules:
submodule: trace adding submodule ODB as alternate
submodule: pass repo to check_has_commit()
object-file: only register submodule ODB if needed
merge-{ort,recursive}: remove add_submodule_odb()
refs: peeling non-the_repository iterators is BUG
refs: teach arbitrary repo support to iterators
refs: plumb repo into ref stores
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
After the parent commit and some of its ancestors, the only place
commits are being accessed through alternates is in the user-facing
message formatting code. Fix those, and remove the add_submodule_odb()
calls.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
More code paths that use the hack to add submodule's object
database to the set of alternate object store have been cleaned up.
* jt/add-submodule-odb-clean-up:
revision: remove "submodule" from opt struct
repository: support unabsorbed in repo_submodule_init
submodule: remove unnecessary unabsorbed fallback
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>
This fixes a long-standing patchwork of ignored files handling in
read-tree and merge-recursive, called out and suggested by Junio long
ago. Quoting from commit dcf0c16ef1 ("core.excludesfile clean-up"
2007-11-16):
git-read-tree takes --exclude-per-directory=<gitignore>,
not because the flexibility was needed. Again, this was
because the option predates the standardization of the ignore
files.
...
On the other hand, I think it makes perfect sense to fix
git-read-tree, git-merge-recursive and git-clean to follow the
same rule as other commands. I do not think of a valid use case
to give an exclude-per-directory that is nonstandard to
read-tree command, outside a "negative" test in the t1004 test
script.
This patch is the first step to untangle this mess.
The next step would be to teach read-tree, merge-recursive and
clean (in C) to use setup_standard_excludes().
History shows each of these were partially or fully fixed:
* clean was taught the new trick in 1617adc7a0 ("Teach git clean to
use setup_standard_excludes()", 2007-11-14).
* read-tree was primarily used by checkout & merge scripts. checkout
and merge later became builtins and were both fixed to use the new
setup_standard_excludes() handling in fc001b526c ("checkout,merge:
loosen overwriting untracked file check based on info/exclude",
2011-11-27). So the primary users were fixed, though read-tree
itself was not.
* merge-recursive has now been replaced as the default merge backend
by merge-ort. merge-ort fixed this by using
setup_standard_excludes() starting early in its implementation; see
commit 6681ce5cf6 ("merge-ort: add implementation of checkout()",
2020-12-13), largely due to its design depending on checkout() and
thus being influenced by the checkout code. However,
merge-recursive itself was not fixed here, in part because its
design meant it had difficulty differentiating between untracked
files, ignored files, leftover tracked files that haven't been
removed yet due to order of processing files, and files written by
itself due to collisions).
Make the conversion more complete by now handling read-tree and
handling at least the unpack_trees() portion of merge-recursive. While
merge-recursive is on its way out, fixing the unpack_trees() portion is
easy and facilitates some of the later changes in this series. Note
that fixing read-tree makes the --exclude-per-directory option to
read-tree useless, so we remove it from the documentation (though we
continue to accept it if passed).
The read-tree changes happen to fix a bug in t1013.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Various mergy operations have been prepared to work efficiently
with the sparse index.
* ds/mergies-with-sparse-index:
sparse-index: integrate with cherry-pick and rebase
sequencer: ensure full index if not ORT strategy
t1092: add cherry-pick, rebase tests
merge-ort: expand only for out-of-cone conflicts
merge: make sparse-aware with ORT
diff: ignore sparse paths in diffstat
Allow 'git merge' to operate without expanding a sparse index, at least
not immediately. The index still will be expanded in a few cases:
1. If the merge strategy is 'recursive', then we enable
command_requires_full_index at the start of the merge_recursive()
method. We expect sparse-index users to also have the 'ort' strategy
enabled.
2. With the 'ort' strategy, if the merge results in a conflicted file,
then we expand the index before updating the working tree. The loop
that iterates over the worktree replaces index entries and tracks
'origintal_cache_nr' which can become completely wrong if the index
expands in the middle of the operation. This safety valve is
important before that loop starts. A later change will focus this
to only expand if we indeed have a conflict outside of the
sparse-checkout cone.
3. Other merge strategies are executed as a 'git merge-X' subcommand,
and those strategies are currently protected with the
'command_requires_full_index' guard.
Some test updates are required, including a mistaken 'git checkout -b'
that did not specify the base branch, causing merges to be fast-forward
merges.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Clean up a TODO in revision.h by removing the "submodule" field from
struct setup_revision_opt. This field is only used to specify the ref
store to use, so use rev_info->repo to determine the ref store instead.
The only users of this field are merge-ort.c and merge-recursive.c.
However, both these files specify the superproject as rev_info->repo and
the submodule as setup_revision_opt->submodule. In order to be able to
pass the submodule as rev_info->repo, all commits must be parsed with
the submodule explicitly specified; this patch does that as well. (An
incremental solution in which only some commits are parsed with explicit
submodule will not work, because if the same commit is parsed twice in
different repositories, there will be 2 heap-allocated object structs
corresponding to that commit, and any flag set by the revision walking
mechanism on one of them will not be reflected onto the other.)
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Call fspathcmp() instead of open-coding it. This shortens the code and
makes it less repetitive.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cf2dc1c238 (speed up alt_odb_usable() with many alternates, 2021-07-07)
introduced the function fspathhash() for calculating path hashes while
respecting the configuration option core.ignorecase. Call it instead of
open-coding it; the resulting code is shorter and less repetitive.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation on "git diff -l<n>" and diff.renameLimit have been
updated, and the defaults for these limits have been raised.
* en/rename-limits-doc:
rename: bump limit defaults yet again
diffcore-rename: treat a rename_limit of 0 as unlimited
doc: clarify documentation for rename/copy limits
diff: correct warning message when renameLimit exceeded
Many "printf"-like helper functions we have have been annotated
with __attribute__() to catch placeholder/parameter mismatches.
* ab/attribute-format:
advice.h: add missing __attribute__((format)) & fix usage
*.h: add a few missing __attribute__((format))
*.c static functions: add missing __attribute__((format))
sequencer.c: move static function to avoid forward decl
*.c static functions: don't forward-declare __attribute__
Code cleanup around struct_type_init() functions.
* ab/struct-init:
string-list.h users: change to use *_{nodup,dup}()
string-list.[ch]: add a string_list_init_{nodup,dup}()
dir.[ch]: replace dir_init() with DIR_INIT
*.c *_init(): define in terms of corresponding *_INIT macro
*.h: move some *_INIT to designated initializers
The merge code had funny interactions between content based rename
detection and directory rename detection.
* en/merge-dir-rename-corner-case-fix:
merge-recursive: handle rename-to-self case
merge-ort: ensure we consult df_conflict and path_conflicts
t6423: test directory renames causing rename-to-self
These were last bumped in commit 92c57e5c1d (bump rename limit
defaults (again), 2011-02-19), and were bumped both because processors
had gotten faster, and because people were getting ugly merges that
caused problems and reporting it to the mailing list (suggesting that
folks were willing to spend more time waiting).
Since that time:
* Linus has continued recommending kernel folks to set
diff.renameLimit=0 (maps to 32767, currently)
* Folks with repositories with lots of renames were happy to set
merge.renameLimit above 32767, once the code supported that, to
get correct cherry-picks
* Processors have gotten faster
* It has been discovered that the timing methodology used last time
probably used too large example files.
The last point is probably worth explaining a bit more:
* The "average" file size used appears to have been average blob size
in the linux kernel history at the time (probably v2.6.25 or
something close to it).
* Since bigger files are modified more frequently, such a computation
weights towards larger files.
* Larger files may be more likely to be modified over time, but are
not more likely to be renamed -- the mean and median blob size
within a tree are a bit higher than the mean and median of blob
sizes in the history leading up to that version for the linux
kernel.
* The mean blob size in v2.6.25 was half the average blob size in
history leading to that point
* The median blob size in v2.6.25 was about 40% of the mean blob size
in v2.6.25.
* Since the mean blob size is more than double the median blob size,
any file as big as the mean will not be compared to any files of
median size or less (because they'd be more than 50% dissimilar).
* Since it is the number of files compared that provides the O(n^2)
behavior, median-sized files should matter more than mean-sized
ones.
The combined effect of the above is that the file size used in past
calculations was likely about 5x too large. Combine that with a CPU
performance improvement of ~30%, and we can increase the limits by
a factor of sqrt(5/(1-.3)) = 2.67, while keeping the original stated
time limits.
Keeping the same approximate time limit probably makes sense for
diff.renameLimit (there is no progress feedback in e.g. git log -p),
but the experience above suggests merge.renameLimit could be extended
significantly. In fact, it probably would make sense to have an
unlimited default setting for merge.renameLimit, but that would
likely need to be coupled with changes to how progress is displayed.
(See https://lore.kernel.org/git/YOx+Ok%2FEYvLqRMzJ@coredump.intra.peff.net/
for details in that area.) For now, let's just bump the approximate
time limit from 10s to 1m.
(Note: We do not want to use actual time limits, because getting results
that depend on how loaded your system is that day feels bad, and because
we don't discover that we won't get all the renames until after we've
put in a lot of work rather than just upfront telling the user there are
too many files involved.)
Using the original time limit of 2s for diff.renameLimit, and bumping
merge.renameLimit from 10s to 60s, I found the following timings using
the simple script at the end of this commit message (on an AWS c5.xlarge
which reports as "Intel(R) Xeon(R) Platinum 8124M CPU @ 3.00GHz"):
N Timing
1300 1.995s
7100 59.973s
So let's round down to nice even numbers and bump the limits from
400->1000, and from 1000->7000.
Here is the measure_rename_perf script (adapted from
https://lore.kernel.org/git/20080211113516.GB6344@coredump.intra.peff.net/
in particular to avoid triggering the linear handling from
basename-guided rename detection):
#!/bin/bash
n=$1; shift
rm -rf repo
mkdir repo && cd repo
git init -q -b main
mkdata() {
mkdir $1
for i in `seq 1 $2`; do
(sed "s/^/$i /" <../sample
echo tag: $1
) >$1/$i
done
}
mkdata initial $n
git add .
git commit -q -m initial
mkdata new $n
git add .
cd new
for i in *; do git mv $i $i.renamed; done
cd ..
git rm -q -rf initial
git commit -q -m new
time git diff-tree -M -l0 --summary HEAD^ HEAD
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add missing __attribute__((format)) function attributes to various
"static" functions that take printf arguments.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change all in-tree users of the string_list_init(LIST, BOOL) API to
use string_list_init_{nodup,dup}(LIST) instead.
As noted in the preceding commit let's leave the now-unused
string_list_init() wrapper in-place for any in-flight users, it can be
removed at some later date.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Directory rename detection can cause transitive renames, e.g. if the two
different sides of history each do one half of:
A/file -> B/file
B/ -> C/
then directory rename detection transitively renames to give us
A/file -> C/file
However, when C/ == A/, note that this gives us
A/file -> A/file.
merge-recursive assumed that any rename D -> E would have D != E. While
that is almost always true, the above is a special case where it is not.
So we cannot do things like delete the rename source, we cannot assume
that a file existing at path E implies a rename/add conflict and we have
to be careful about what stages end up in the output.
This change feels a bit hackish. It took me surprisingly many hours to
find, and given merge-recursive's design causing it to attempt to
enumerate all combinations of edge and corner cases with special code
for each combination, I'm worried there are other similar fixes needed
elsewhere if we can just come up with the right special testcase.
Perhaps an audit would rule it out, but I have not the energy.
merge-recursive deserves to die, and since it is on its way out anyway,
fixing this particular bug narrowly will have to be good enough.
Reported-by: Anders Kaseorg <andersk@mit.edu>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix typos in documentation, code comments, and RelNotes which repeat
various words. In trivial cases, just delete the duplicated word and
rewrap text, if needed. Reword the affected sentence in
Documentation/RelNotes/1.8.4.txt for it to make sense.
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A few variants of informational message "Already up-to-date" has
been rephrased.
* js/merge-already-up-to-date-message-reword:
merge: fix swapped "up to date" message components
merge(s): apply consistent punctuation to "up to date" messages
SHA-256 transition.
* bc/hash-transition-interop-part-1:
hex: print objects using the hash algorithm member
hex: default to the_hash_algo on zero algorithm value
builtin/pack-objects: avoid using struct object_id for pack hash
commit-graph: don't store file hashes as struct object_id
builtin/show-index: set the algorithm for object IDs
hash: provide per-algorithm null OIDs
hash: set, copy, and use algo field in struct object_id
builtin/pack-redundant: avoid casting buffers to struct object_id
Use the final_oid_fn to finalize hashing of object IDs
hash: add a function to finalize object IDs
http-push: set algorithm when reading object ID
Always use oidread to read into struct object_id
hash: add an algo member to struct object_id
Although the various "Already up to date" messages resulting from merge
attempts share identical phrasing, they use a mix of punctuation ranging
from "." to "!" and even "Yeeah!", which leads to extra work for
translators. Ease the job of translators by settling upon "." as
punctuation for all such messages.
While at it, take advantage of printf_ln() to further ease the
translation task so translators need not worry about line termination,
and fix a case of missing line termination in the (unused)
merge_ort_nonrecursive() function.
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Builds on top of the sparse-index infrastructure to mark operations
that are not ready to mark with the sparse index, causing them to
fall back on fully-populated index that they always have worked with.
* ds/sparse-index-protections: (47 commits)
name-hash: use expand_to_path()
sparse-index: expand_to_path()
name-hash: don't add directories to name_hash
revision: ensure full index
resolve-undo: ensure full index
read-cache: ensure full index
pathspec: ensure full index
merge-recursive: ensure full index
entry: ensure full index
dir: ensure full index
update-index: ensure full index
stash: ensure full index
rm: ensure full index
merge-index: ensure full index
ls-files: ensure full index
grep: ensure full index
fsck: ensure full index
difftool: ensure full index
commit: ensure full index
checkout: ensure full index
...
Up until recently, object IDs did not have an algorithm member, only a
hash. Consequently, it was possible to share one null (all-zeros)
object ID among all hash algorithms. Now that we're going to be
handling objects from multiple hash algorithms, it's important to make
sure that all object IDs have a correct algorithm field.
Introduce a per-algorithm null OID, and add it to struct hash_algo.
Introduce a wrapper function as well, and use it everywhere we used to
use the null_oid constant.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Plug the ort merge backend throughout the rest of the system, and
start testing it as a replacement for the recursive backend.
* en/ort-readiness:
Add testing with merge-ort merge strategy
t6423: mark remaining expected failure under merge-ort as such
Revert "merge-ort: ignore the directory rename split conflict for now"
merge-recursive: add a bunch of FIXME comments documenting known bugs
merge-ort: write $GIT_DIR/AUTO_MERGE whenever we hit a conflict
t: mark several submodule merging tests as fixed under merge-ort
merge-ort: implement CE_SKIP_WORKTREE handling with conflicted entries
t6428: new test for SKIP_WORKTREE handling and conflicts
merge-ort: support subtree shifting
merge-ort: let renormalization change modify/delete into clean delete
merge-ort: have ll_merge() use a special attr_index for renormalization
merge-ort: add a special minimal index just for renormalization
merge-ort: use STABLE_QSORT instead of QSORT where required
Before iterating over all cache entries, ensure that a sparse index is
expanded to a full index to avoid unexpected behavior.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Several methods specify that they take a 'struct index_state' pointer
with the 'const' qualifier because they intend to only query the data,
not change it. However, we will be introducing a step very low in the
method stack that might modify a sparse-index to become a full index in
the case that our queries venture inside a sparse-directory entry.
This change only removes the 'const' qualifiers that are necessary for
the following change which will actually modify the implementation of
index_name_stage_pos().
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code simplification by removing support for a caller that is long gone.
* ab/read-tree:
tree.h API: simplify read_tree_recursive() signature
tree.h API: expose read_tree_1() as read_tree_at()
archive: stop passing "stage" through read_tree_recursive()
ls-files: refactor away read_tree()
ls-files: don't needlessly pass around stage variable
tree.c API: move read_tree() into builtin/ls-files.c
ls-files tests: add meaningful --with-tree tests
show tests: add test for "git show <tree>"
Simplify the signature of read_tree_recursive() to omit the "base",
"baselen" and "stage" arguments. No callers of it use these parameters
for anything anymore.
The last function to call read_tree_recursive() with a non-"" path was
read_tree_recursive() itself, but that was changed in
ffd31f661d (Reimplement read_tree_recursive() using
tree_entry_interesting(), 2011-03-25).
The last user of the "stage" parameter went away in the last commit,
and even that use was mere boilerplate.
So let's remove those and rename the read_tree_recursive() function to
just read_tree(). We had another read_tree() function that I've
refactored away in preceding commits, since all in-tree users read
trees recursively with a callback we can change the name to signify
that this is the norm.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The plan is to just delete merge-recursive, but not until everyone is
comfortable with merge-ort as a replacement. Given that I haven't
switched all callers of merge-recursive over yet (e.g. git-am still uses
merge-recursive), maybe there's some value documenting known bugs in the
algorithm in case we end up keeping it or someone wants to dig it up in
the future.
Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add and apply a semantic patch for converting code that open-codes
CALLOC_ARRAY to use it instead. It shortens the code and infers the
element size automatically.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
hashmap_free(), hashmap_free_entries(), and hashmap_free_() have existed
for a while, but aren't necessarily the clearest names, especially with
hashmap_partial_clear() being added to the mix and lazy-initialization
now being supported. Peff suggested we adopt the following names[1]:
- hashmap_clear() - remove all entries and de-allocate any
hashmap-specific data, but be ready for reuse
- hashmap_clear_and_free() - ditto, but free the entries themselves
- hashmap_partial_clear() - remove all entries but don't deallocate
table
- hashmap_partial_clear_and_free() - ditto, but free the entries
This patch provides the new names and converts all existing callers over
to the new naming scheme.
[1] https://lore.kernel.org/git/20201030125059.GA3277724@coredump.intra.peff.net/
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
All "mergy" operations that internally use the merge-recursive
machinery should honor the merge.renormalize configuration, but
many of them didn't.
* en/eol-attrs-gotchas:
checkout: support renormalization with checkout -m <paths>
merge: make merge.renormalize work for all uses of merge machinery
t6038: remove problematic test
t6038: make tests fail for the right reason
The 'merge' command is not the only one that does merges; other commands
like checkout -m or rebase do as well. Unfortunately, the only area of
the code that checked for the "merge.renormalize" config setting was in
builtin/merge.c, meaning it could only affect merges performed by the
"merge" command. Move the handling of this config setting to
merge_recursive_config() so that other commands can benefit from it as
well. Fixes a few tests in t6038.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commits 7c0a6c8e47 ("merge-recursive: move some definitions around to
clean up the header", 2019-08-17), and b4db8a2b76 ("merge-recursive:
remove useless parameter in merge_trees()", 2019-08-17) added some
useful documentation to the functions, but had a few places where the
new comments were unclear or even misleading. Fix those comments.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
With a rename/rename(1to2) conflict, we attempt to do a three-way merge
of the file contents, so that the correct contents can be placed in the
working tree at both paths. If the file is a binary, however, no
content merging is possible and we should just use the original version
of the file at each of the paths.
Reported-by: Chunlin Zhang <zhangchunlin@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a variety of situations where a filter process can make use of
some additional metadata. For example, some people find the ident
filter too limiting and would like to include the commit or the branch
in their smudged files. This information isn't available during
checkout as HEAD hasn't been updated at that point, and it wouldn't be
available in archives either.
Let's add a way to pass this metadata down to the filter. We pass the
blob we're operating on, the treeish (preferring the commit over the
tree if one exists), and the ref we're operating on. Note that we won't
pass this information in all cases, such as when renormalizing or when
we're performing diffs, since it doesn't make sense in those cases.
The data we currently get from the filter process looks like the
following:
command=smudge
pathname=git.c
0000
With this change, we'll get data more like this:
command=smudge
pathname=git.c
refname=refs/tags/v2.25.1
treeish=c522f061d551c9bb8684a7c3859b2ece4499b56b
blob=7be7ad34bd053884ec48923706e70c81719a8660
0000
There are a couple things to note about this approach. For operations
like checkout, treeish will always be a commit, since we cannot check
out individual trees, but for other operations, like archive, we can end
up operating on only a particular tree, so we'll provide only a tree as
the treeish. Similar comments apply for refname, since there are a
variety of cases in which we won't have a ref.
This commit wires up the code to print this information, but doesn't
pass any of it at this point. In a future commit, we'll have various
code paths pass the actual useful data down.
Signed-off-by: brian m. carlson <bk2204@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Handling of conflicting renames in merge-recursive have further
been made consistent with how existing codepaths try to mimic what
is done to add/add conflicts.
* en/merge-path-collision:
merge-recursive: apply collision handling unification to recursive case
The merge-recursive machinery failed to refresh the cache entry for
a merge result in a couple of places, resulting in an unnecessary
merge failure, which has been fixed.
* en/t3433-rebase-stat-dirty-failure:
merge-recursive: fix the refresh logic in update_file_flags
t3433: new rebase testcase documenting a stat-dirty-like failure
In the en/merge-path-collision topic (see commit ac193e0e0a, "Merge
branch 'en/merge-path-collision'", 2019-01-04), all the "file collision"
conflict types were modified for consistency. In particular,
rename/add, rename/rename(2to1) and each rename/add piece of a
rename/rename(1to2)/add[/add] conflict were made to behave like add/add
conflicts have always been handled.
However, this consistency was not enforced when opt->priv->call_depth >
0 for rename/rename conflicts. Update rename/rename(1to2) and
rename/rename(2to1) conflicts in the recursive case to also be
consistent. As an added bonus, this simplifies the code considerably.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we need to delete a higher stage entry in the index to place the file
at stage 0, then we'll lose that file's stat information. In such
situations we may still be able to detect that the file on disk is the
version we want (as noted by our comment in the code:
/* do not overwrite file if already present */
), but we do still need to update the mtime since we are creating a new
cache_entry for that file. Update the logic used to determine whether
we refresh a file's mtime.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The flip_stage() helper uses a bit-flipping xor to switch between "2"
and "3". While clever, this relies on a property of those two numbers
that is mostly coincidence. Let's write it as a subtraction; that's more
clear and would extend to other numbers if somebody copies the logic.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The merge-recursive code uses stage number constants like this:
add = &ci->ren1->dst_entry->stages[2 ^ 1];
...
add = &ci->ren2->dst_entry->stages[3 ^ 1];
The xor has the effect of flipping the "1" bit, so that "2 ^ 1" becomes
"3" and "3 ^ 1" becomes "2", which correspond to the "ours" and "theirs"
stages respectively.
Unfortunately, clang-10 and up issue a warning for this code:
merge-recursive.c:1759:40: error: result of '2 ^ 1' is 3; did you mean '1 << 1' (2)? [-Werror,-Wxor-used-as-pow]
add = &ci->ren1->dst_entry->stages[2 ^ 1];
~~^~~
1 << 1
merge-recursive.c:1759:40: note: replace expression with '0x2 ^ 1' to silence this warning
We could silence it by using 0x2, as the compiler mentions. Or by just
using the constants "2" and "3" directly. But after digging into it, I
do think this bit-flip is telling us something. If we just wrote:
add = &ci->ren2->dst_entry->stages[2];
for the second one, you might think that "ren2" and "2" correspond. But
they don't. The logic is: ren2 is theirs, which is stage 3, but we
are interested in the opposite side's stage, so flip it to 2.
So let's keep the bit-flipping, but let's also put it behind a named
function, which will make its purpose a bit clearer. This also has the
side effect of suppressing the warning (and an optimizing compiler
should be able to easily turn it into a constant as before).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Back when merge-recursive was first introduced in commit 6d297f8137
(Status update on merge-recursive in C, 2006-07-08), it created a
sha_eq() function. This function pre-dated the introduction of
hashcmp() to cache.h by about a month, but was switched over to using
hashcmp() as part of commit 9047ebbc22 (Split out merge_recursive() to
merge-recursive.c, 2008-08-12). In commit b4da9d62f9 (merge-recursive:
convert leaf functions to use struct object_id, 2016-06-24), sha_eq() was
renamed to oid_eq() and its hashcmp() call was switched to oideq().
oid_eq() is basically just a wrapper around oideq() that has some extra
checks to protect against NULL arguments or to allow short-circuiting if
one of the arguments is NULL. I don't know if any caller ever tried to
call with NULL arguments, but certainly none do now which means the
extra checks serve no purpose. (Also, if these checks were genuinely
useful, then they probably should be added to the main oideq() so all
callers could benefit from them.)
Reduce the cognitive overhead of having both oid_eq() and oideq(), by
getting rid of merge-recursive's special oid_eq() wrapper.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When all files from some subdirectory were renamed to the root
directory, the directory rename heuristics would fail to detect that
as a rename/merge of the subdirectory to the root directory, which has
been corrected.
* en/merge-recursive-directory-rename-fixes:
t604[236]: do not run setup in separate tests
merge-recursive: fix merging a subdirectory into the root directory
merge-recursive: clean up get_renamed_dir_portion()
We allow renaming all entries in e.g. a directory named z/ into a
directory named y/ to be detected as a z/ -> y/ rename, so that if the
other side of history adds any files to the directory z/ in the mean
time, we can provide the hint that they should be moved to y/.
There is no reason to not allow 'y/' to be the root directory, but the
code did not handle that case correctly. Add a testcase and the
necessary special checks to support this case.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Dscho noted a few things making this function hard to follow.
Restructure it a bit and add comments to make it easier to follow. The
restructurings include:
* There was a special case if-check at the end of the function
checking whether someone just renamed a file within its original
directory, meaning that there could be no directory rename involved.
That check was slightly convoluted; it could be done in a more
straightforward fashion earlier in the function, and can be done
more cheaply too (no call to strncmp).
* The conditions for advancing end_of_old and end_of_new before
calling strchr were both confusing and unnecessary. If either
points at a '/', then they need to be advanced in order to find the
next '/'. If either doesn't point at a '/', then advancing them one
char before calling strchr() doesn't hurt. So, just rip out the
if conditions and advance both before calling strchr().
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The merge-recursive machiery is one of the most complex parts of
the system that accumulated cruft over time. This large series
cleans up the implementation quite a bit.
* en/merge-recursive-cleanup: (26 commits)
merge-recursive: fix the fix to the diff3 common ancestor label
merge-recursive: fix the diff3 common ancestor label for virtual commits
merge-recursive: alphabetize include list
merge-recursive: add sanity checks for relevant merge_options
merge-recursive: rename MERGE_RECURSIVE_* to MERGE_VARIANT_*
merge-recursive: split internal fields into a separate struct
merge-recursive: avoid losing output and leaking memory holding that output
merge-recursive: comment and reorder the merge_options fields
merge-recursive: consolidate unnecessary fields in merge_options
merge-recursive: move some definitions around to clean up the header
merge-recursive: rename merge_options argument to opt in header
merge-recursive: rename 'mrtree' to 'result_tree', for clarity
merge-recursive: use common name for ancestors/common/base_list
merge-recursive: fix some overly long lines
cache-tree: share code between functions writing an index as a tree
merge-recursive: don't force external callers to do our logging
merge-recursive: remove useless parameter in merge_trees()
merge-recursive: exit early if index != head
Ensure index matches head before invoking merge machinery, round N
merge-recursive: remove another implicit dependency on the_repository
...
In commit 8e4ec337 ("merge-recursive: fix the diff3 common ancestor
label for virtual commits", 2019-10-01), which was a fix to commit
743474cbfa ("merge-recursive: provide a better label for diff3
common ancestor", 2019-08-17), the label for the common ancestor was
changed from always being
"merged common ancestors"
to instead be based on the number of merge bases and whether the merge
base was a real commit or a virtual one:
>=2: "merged common ancestors"
1, via merge_recursive_generic: "constructed merge base"
1, otherwise: <abbreviated commit hash>
0: "<empty tree>"
The handling for "constructed merge base" worked by allowing
opt->ancestor to be set in merge_recursive_generic(), so we paid
attention to the setting of that variable in merge_recursive_internal().
Now, for the outer merge, the code flow was simply the following:
ancestor_name = "merged merge bases"
loop over merge_bases: merge_recursive_internal()
The first merge base not needing recursion would determine its own
ancestor_name however necessary and thus run
ancestor_name = $SOMETHING
empty loop over merge_bases...
opt->ancestor = ancestor_name
merge_trees_internal()
Now, the next set of merge_bases that would need to be merged after this
particular merge had completed would note that opt->ancestor has been
set to something (to a local ancestor_name variable that has since been
popped off the stack), and thus it would run:
... else if (opt->ancestor) {
ancestor_name = opt->ancestor; /* OOPS! */
loop over merge_bases: merge_recursive_internal()
opt->ancestor = ancestor_name
merge_trees_internal()
This resulted in garbage strings being printed for the virtual merge
bases, which was visible in git.git by just merging commit b744c3af07
into commit 6d8cb22a4f. There are two ways to fix this: set
opt->ancestor to NULL after using it to avoid re-use, or add a
!opt->priv->call_depth check to the if block for using a pre-defined
opt->ancestor. Apply both fixes.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since these macros already take a `keyvar' pointer of a known type,
we can rely on OFFSETOF_VAR to get the correct offset without
relying on non-portable `__typeof__' and `offsetof'.
Argument order is also rearranged, so `keyvar' and `member' are
sequential as they are used as: `keyvar->member'
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While we cannot rely on a `__typeof__' operator being portable
to use with `offsetof'; we can calculate the pointer offset
using an existing pointer and the address of a member using
pointer arithmetic for compilers without `__typeof__'.
This allows us to simplify usage of hashmap iterator macros
by not having to specify a type when a pointer of that type
is already given.
In the future, list iterator macros (e.g. list_for_each_entry)
may also be implemented using OFFSETOF_VAR to save hackers the
trouble of using container_of/list_entry macros and without
relying on non-portable `__typeof__'.
v3: use `__typeof__' to avoid clang warnings
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`hashmap_free_entries' behaves like `container_of' and passes
the offset of the hashmap_entry struct to the internal
`hashmap_free_' function, allowing the function to free any
struct pointer regardless of where the hashmap_entry field
is located.
`hashmap_free' no longer takes any arguments aside from
the hashmap itself.
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Inspired by list_for_each_entry in the Linux kernel.
Once again, these are somewhat compromised usability-wise
by compilers lacking __typeof__ support.
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Another step in eliminating the requirement of hashmap_entry
being the first member of a struct.
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update callers to use hashmap_get_entry, hashmap_get_entry_from_hash
or container_of as appropriate.
This is another step towards eliminating the requirement of
hashmap_entry being the first field in a struct.
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is less error-prone than "void *" as the compiler now
detects invalid types being passed.
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is less error-prone than "const void *" as the compiler
now detects invalid types being passed.
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is less error-prone than "const void *" as the compiler
now detects invalid types being passed.
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is less error-prone than "void *" as the compiler now
detects invalid types being passed.
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
C compilers do type checking to make life easier for us. So
rely on that and update all hashmap_entry_init callers to take
"struct hashmap_entry *" to avoid future bugs while improving
safety and readability.
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In commit 743474cbfa ("merge-recursive: provide a better label for
diff3 common ancestor", 2019-08-17), the label for the common ancestor
was changed from always being
"merged common ancestors"
to instead be based on the number of merge bases:
>=2: "merged common ancestors"
1: <abbreviated commit hash>
0: "<empty tree>"
Unfortunately, this did not take into account that when we have a single
merge base, that merge base could be fake or constructed. In such
cases, this resulted in a label of "00000000". Of course, the previous
label of "merged common ancestors" was also misleading for this case.
Since we have an API that is explicitly about creating fake merge base
commits in merge_recursive_generic(), we should provide a better label
when using that API with one merge base. So, when
merge_recursive_generic() is called with one merge base, set the label
to:
"constructed merge base"
Note that callers of merge_recursive_generic() include the builtin
commands git-am (in combination with git apply --build-fake-ancestor),
git-merge-recursive, and git-stash.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the working tree has:
- bar (directory)
- bar/file (file)
- foo (symlink to .)
(note that lstat() for "foo/bar" would tell us that it is a directory)
and the user merges a commit that deletes the foo symlink and instead
contains:
- bar (directory, as above)
- bar/file (file, as above)
- foo (directory)
- foo/bar (file)
the merge should happen without requiring user intervention. However,
this does not happen.
This is because dir_in_way(), when checking the working tree, thinks
that "foo/bar" is a directory. But a symlink should be treated much the
same as a file: since dir_in_way() is only checking to see if there is a
directory in the way, we don't want symlinks in leading paths to
sometimes cause dir_in_way() to return true.
Teach dir_in_way() to also check for symlinks in leading paths before
reporting whether a directory is in the way.
Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Other than cache.h which needs to appear first, and merge-recursive.h
which I want to be second so that we are more likely to notice if
merge-recursive.h has any missing includes, the rest of the list is
long and easier to look through if it's alphabetical.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are lots of options that callers can set, yet most have a limited
range of valid values, some options are meant for output (e.g.
opt->obuf, which is expected to start empty), and callers are expected
to not set opt->priv. Add several sanity checks to ensure callers
provide sane values.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
I want to implement the same outward facing API as found within
merge-recursive.h in a different merge strategy. However, that makes
names like MERGE_RECURSIVE_{NORMAL,OURS,THEIRS} look a little funny;
rename to MERGE_VARIANT_{NORMAL,OURS,THEIRS}.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge_options has several internal fields that should not be set or read
by external callers. This just complicates the API. Move them into an
opaque merge_options_internal struct that is defined only in
merge-recursive.c and keep these out of merge-recursive.h.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If opt->buffer_output is less than 2, then merge_trees(),
merge_recursive(), and merge_recursive_generic() are all supposed to
flush the opt->obuf output buffer to stdout and release any memory it
holds. merge_trees() did not do this. Move the logic that handles this
for merge_recursive_internal() to merge_finalize() so that all three
methods handle this requirement.
Note that this bug didn't cause any problems currently, because there
are only two callers of merge_trees() right now (a git grep for
'merge_trees(' is misleading because builtin/merge-tree.c also defines a
'merge_tree' function that is unrelated), and only one of those is
called with buffer_output less than 2 (builtin/checkout.c), but it set
opt->verbosity to 0, for which there is only currently one non-error
message that would be shown: "Already up to date!". However, that one
message can only occur when the merge is utterly trivial (the merge base
tree exactly matches the merge tree), and builtin/checkout.c already
attempts a trivial merge via unpack_trees() before falling back to
merge_trees().
Also, if opt->buffer_output is 2, then the caller is responsible to
handle showing any output in opt->obuf and for free'ing it. This
requirement might be easy to overlook, so add a comment to
merge-recursive.h pointing it out. (There are currently two callers
that set buffer_output to 2, both in sequencer.c, and both of which
handle this correctly.)
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The merge_options struct had lots of fields, making it a little
imposing, but the options naturally fall into multiple different groups.
Grouping similar options and adding a comment or two makes it easier to
read, easier for new folks to figure out which options are related, and
thus easier for them to find the options they need.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We provided users with the ability to state whether they wanted rename
detection, and to put a limit on how much CPU would be spent. Both of
these fields had multiple configuration parameters for setting them,
with one being a fallback and the other being an override. However,
instead of implementing the logic for how to combine the multiple
source locations into the appropriate setting at config loading time,
we loaded and tracked both values and then made the code combine them
every time it wanted to check the overall value. This had a few
minor drawbacks:
* it seems more complicated than necessary
* it runs the risk of people using the independent settings in the
future and breaking the intent of how the options are used
together
* it makes merge_options more complicated than necessary for other
potential users of the API
Fix these problems by moving the logic for combining the pairs of
options into a single value; make it apply at time-of-config-loading
instead of each-time-of-use.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
No substantive code changes (view this with diff --color-moved), but
a few small code cleanups:
* Move structs and an inline function only used by merge-recursive.c
into merge-recursive.c
* Re-order function declarations to be more logical
* Add or fix some explanatory comments
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is not at all clear what 'mr' was supposed to stand for, at least not
to me. Pick a clearer name for this variable.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge_trees(), merge_recursive(), and merge_recursive_generic() in
their function headers used four different names for the merge base or
list of merge bases they were passed:
* 'common'
* 'ancestors'
* 'ca'
* 'base_list'
They were able to refer to it four different ways instead of only three
by using a different name in the signature for the .c file than the .h
file. Change all of these to 'merge_base' or 'merge_bases'.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
No substantive code change, just add some line breaks to fix lines that
have grown in length due to various refactorings. Most remaining lines
of excessive length in merge-recursive include error messages and it's
not clear that splitting those improves things.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
write_tree_from_memory() appeared to be a merge-recursive special that
basically duplicated write_index_as_tree(). The two have a different
signature, but the bigger difference was just that write_index_as_tree()
would always unconditionally read the index off of disk instead of
working on the current in-memory index. So:
* split out common code into write_index_as_tree_internal()
* rename write_tree_from_memory() to write_inmemory_index_as_tree(),
make it call write_index_as_tree_internal(), and move it to
cache-tree.c
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Alternatively, you can view this as "make the merge functions behave
more similarly." merge-recursive has three different entry points:
merge_trees(), merge_recursive(), and merge_recursive_generic(). Two of
these would call diff_warn_rename_limit(), but merge_trees() didn't.
This lead to callers of merge_trees() needing to manually call
diff_warn_rename_limit() themselves. Move this to the new
merge_finalize() function to make sure that all three entry points run
this function.
Note that there are two external callers of merge_trees(), one in
sequencer.c and one in builtin/checkout.c. The one in sequencer.c is
cleaned up by this patch and just transfers where the call to
diff_warn_rename_limit() is made; the one in builtin/checkout.c is for
switching to a different commit and in the very rare case where the
warning might be triggered, it would probably be helpful to include
(e.g. if someone is modifying a file that has been renamed in moving to
the other commit, but there are so many renames between the commits that
the limit kicks in and none are detected, it may help to have an
explanation about why they got a delete/modify conflict instead of a
proper content merge in a renamed file).
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge_trees() took a results parameter that would only be written when
opt->call_depth was positive, which is never the case now that
merge_trees_internal() has been split from merge_trees(). Remove the
misleading and unused parameter from merge_trees().
While at it, add some comments explaining how the output of
merge_trees() and merge_recursive() differ.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We had a rule to enforce that the index matches head, but it was found
at the beginning of merge_trees() and would only trigger when
opt->call_depth was 0. Since merge_recursive() doesn't call
merge_trees() until after returning from recursing, this meant that the
check wasn't triggered by merge_recursive() until it had first finished
all the intermediate merges to create virtual merge bases. That is a
potentially huge amount of computation (and writing of intermediate
merge results into the .git/objects directory) before it errors out and
says, in effect, "Sorry, I can't do any merging because you have some
local changes that would be overwritten."
Further, not enforcing this requirement earlier allowed other bugs (such
as an unintentional unconditional dropping and reloading of the index in
merge_recursive() even when no recursion was necessary), to mask bugs in
other callers (which were fixed in the commit prior to this one).
Make sure we do the index == head check at the beginning of the merge,
and error out immediately if it fails. While we're at it, fix a small
leak in the show-the-error codepath.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit d7cf3a96e9 ("merge-recursive.c: remove implicit dependency on
the_repository", 2019-01-12) and follow-ups like commit 34e7771bc6
("Use the right 'struct repository' instead of the_repository",
2019-06-27), removed most implicit uses of the_repository. Convert
calls to get_commit_tree() to instead use repo_get_commit_tree() to get
rid of another.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is a 'free_buf' label to which all but one of the error paths in
update_file_flags() jump; that error case involves a NULL buf and is
thus not a memory leak. However, make that error case execute the same
deallocation code anyway so that if anyone adds any additional memory
allocations or deallocations, then all error paths correctly deallocate
resources.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Improve code readability by introducing an enum to replace the
not-quite-boolean values taken on by detect_directory_renames.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In commit 7ca56aa076 ("merge-recursive: add a label for ancestor",
2010-03-20), a label was added for the '||||||' line to make it have
the more informative heading '|||||| merged common ancestors', with
the statement:
It would be nicer to use a more informative label. Perhaps someone
will provide one some day.
This chosen label was perfectly reasonable when recursiveness kicks in,
i.e. when there are multiple merge bases. (I can't think of a better
label in such cases.) But it is actually somewhat misleading when there
is a unique merge base or no merge base. Change this based on the
number of merge bases:
>=2: "merged common ancestors"
1: <abbreviated commit hash>
0: "<empty tree>"
Tests have also been added to check that we get the right ancestor name
for each of the three cases.
Also, since merge_recursive() and merge_trees() have polar opposite
pre-conditions for opt->ancestor, document merge_recursive()'s
pre-condition with an assertion. (An assertion was added to
merge_trees() already a few commits ago.) The differences in
pre-conditions stem from two factors: (1) merge_trees() does not recurse
and thus does not have multiple sub-merges to worry about -- each of
which would require a different value for opt->ancestor, (2)
merge_trees() is only passed trees rather than commits and thus cannot
internally guess as good of a label. Thus, while external callers of
merge_trees() are required to provide a non-NULL opt->ancestor,
merge_recursive() expects to set this value itself.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We always want our conflict hunks to be labelled so that users can know
where each came from. The previous commit fixed the one caller in the
codebase which was not setting opt->ancestor (and thus not providing a
label for the "merge base" conflict hunk in diff3-style conflict
markers); add an assertion to prevent future codepaths from also
overlooking this requirement.
Enforcing this requirement also allows us to simplify the code for
labelling the conflict hunks by no longer checking if the ancestor label
is NULL.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In commit 8daec1df03 ("merge-recursive: switch from (oid,mode) pairs
to a diff_filespec", 2019-04-05), an assertion on a->path && b->path
was added for code readability to document that these both needed to be
non-NULL at this point in the code. However, the subsequent lines also
read o->path, so it should be included in the assert.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"merge-recursive" hit a BUG() when building a virtual merge base
detected a directory rename.
* en/disable-dir-rename-in-recursive-merge:
merge-recursive: avoid directory rename detection in recursive case
Ever since commit 8c8e5bd6eb ("merge-recursive: switch directory
rename detection default", 2019-04-05), the default handling with
directory rename detection was to report a conflict and leave unstaged
entries in the index. However, when creating a virtual merge base in
the recursive case, we absolutely need a tree, and the only way a tree
can be written is if we have no unstaged entries -- otherwise we hit a
BUG().
There are a few fixes possible here which at least fix the BUG(), but
none of them seem optimal for other reasons; see the comments with the
new testcase 13e in t6043 for details (which testcase triggered a BUG()
prior to this patch). As such, just opt for a very conservative and
simple choice that is still relatively reasonable: have the recursive
case treat 'conflict' as 'false' for opt->detect_directory_renames.
Reported-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a couple of places where 'struct repository' is already passed
around, but the_repository is still used. Use the right repo.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In commit 8daec1df03 ("merge-recursive: switch from (oid,mode) pairs
to a diff_filespec", 2019-04-05), we actually switched from
(oid,mode,path) triplets to a diff_filespec -- but most callsites in the
patch only needed to worry about oid and mode so the commit message
focused on that. The oversight in the commit message apparently spilled
over to the code as well; one of the dozen or so callsites accidentally
dropped the setting of the path in the conversion. Restore the path
setting in that location.
Also, this pointed out that our testsuite was lacking a good rename/add
test, at least one that involved the need for merge content with the
rename. Add such a test, and since rename/add vs. add/rename could
possibly be important, redo the merge the opposite direction to make
sure we don't have issues with the direction of the merge. These
testcases failed before restoring the setting of path, but with the
paths appropriately set the testcases both pass.
Reported-by: Ben Humphreys <behumphreys@atlassian.com>
Based-on-patch-by: SZEDER Gábor <szeder.dev@gmail.com>
Tested-by: Ben Humphreys <behumphreys@atlassian.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Further code clean-up to allow the lowest level of name-to-object
mapping layer to work with a passed-in repository other than the
default one.
* nd/sha1-name-c-wo-the-repository: (34 commits)
sha1-name.c: remove the_repo from get_oid_mb()
sha1-name.c: remove the_repo from other get_oid_*
sha1-name.c: remove the_repo from maybe_die_on_misspelt_object_name
submodule-config.c: use repo_get_oid for reading .gitmodules
sha1-name.c: add repo_get_oid()
sha1-name.c: remove the_repo from get_oid_with_context_1()
sha1-name.c: remove the_repo from resolve_relative_path()
sha1-name.c: remove the_repo from diagnose_invalid_index_path()
sha1-name.c: remove the_repo from handle_one_ref()
sha1-name.c: remove the_repo from get_oid_1()
sha1-name.c: remove the_repo from get_oid_basic()
sha1-name.c: remove the_repo from get_describe_name()
sha1-name.c: remove the_repo from get_oid_oneline()
sha1-name.c: add repo_interpret_branch_name()
sha1-name.c: remove the_repo from interpret_branch_mark()
sha1-name.c: remove the_repo from interpret_nth_prior_checkout()
sha1-name.c: remove the_repo from get_short_oid()
sha1-name.c: add repo_for_each_abbrev()
sha1-name.c: store and use repo in struct disambiguate_state
sha1-name.c: add repo_find_unique_abbrev_r()
...
"git merge-recursive" backend recently learned a new heuristics to
infer file movement based on how other files in the same directory
moved. As this is inherently less robust heuristics than the one
based on the content similarity of the file itself (rather than
based on what its neighbours are doing), it sometimes gives an
outcome unexpected by the end users. This has been toned down to
leave the renamed paths in higher/conflicted stages in the index so
that the user can examine and confirm the result.
* en/merge-directory-renames:
merge-recursive: switch directory rename detection default
merge-recursive: give callers of handle_content_merge() access to contents
merge-recursive: track information associated with directory renames
t6043: fix copied test description to match its purpose
merge-recursive: switch from (oid,mode) pairs to a diff_filespec
merge-recursive: cleanup handle_rename_* function signatures
merge-recursive: track branch where rename occurred in rename struct
merge-recursive: remove ren[12]_other fields from rename_conflict_info
merge-recursive: shrink rename_conflict_info
merge-recursive: move some struct declarations together
merge-recursive: use 'ci' for rename_conflict_info variable name
merge-recursive: rename locals 'o' and 'a' to 'obuf' and 'abuf'
merge-recursive: rename diff_filespec 'one' to 'o'
merge-recursive: rename merge_options argument from 'o' to 'opt'
Use 'unsigned short' for mode, like diff_filespec does
"maybe" pointer in 'struct commit' is tricky because it can be lazily
initialized to take advantage of commit-graph if available. This makes
it not safe to access directly.
This leads to a rule in commit.cocci to rewrite 'x->maybe_tree' to
'get_commit_tree(x)'. But that rule alone could lead to incorrectly
rewrite assignments, e.g. from
x->maybe_tree = yes
to
get_commit_tree(x) = yes
Because of this we have a second rule to revert this effect. Szeder
found out that we could do better by performing the assignment rewrite
rule first, then the remaining is read-only access and handled by the
current first rule.
For this to work, we need to transform "x->maybe_tree = y" to something
that does NOT contain "x->maybe_tree" to avoid the original first
rule. This is where set_commit_tree() comes in.
Helped-by: SZEDER Gábor <szeder.dev@gmail.com>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When all of x/a, x/b, and x/c have moved to z/a, z/b, and z/c on one
branch, there is a question about whether x/d added on a different
branch should remain at x/d or appear at z/d when the two branches are
merged. There are different possible viewpoints here:
A) The file was placed at x/d; it's unrelated to the other files in
x/ so it doesn't matter that all the files from x/ moved to z/ on
one branch; x/d should still remain at x/d.
B) x/d is related to the other files in x/, and x/ was renamed to z/;
therefore x/d should be moved to z/d.
Since there was no ability to detect directory renames prior to
git-2.18, users experienced (A) regardless of context. Choice (B) was
implemented in git-2.18, with no option to go back to (A), and has been
in use since. However, one user reported that the merge results did not
match their expectations, making the change of default problematic,
especially since there was no notice printed when directory rename
detection moved files.
Note that there is also a third possibility here:
C) There are different answers depending on the context and content
that cannot be determined by git, so this is a conflict. Use a
higher stage in the index to record the conflict and notify the
user of the potential issue instead of silently selecting a
resolution for them.
Add an option for users to specify their preference for whether to use
directory rename detection, and default to (C). Even when directory
rename detection is on, add notice messages about files moved into new
directories.
As a sidenote, x/d did not have to be a new file here; it could have
already existed at some other path and been renamed to x/d, with
directory rename detection just renaming it again to z/d. Thus, it's
not just new files, but also a modification to all rename types (normal
renames, rename/add, rename/delete, rename/rename(1to1),
rename/rename(1to2), and rename/rename(2to1)).
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
