directory renaming and merging can cause one or more files to be moved to
where an existing file is, or to cause several files to all be moved to
the same (otherwise vacant) location. Add checking and reporting for such
cases, falling back to no-directory-rename handling for such paths.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before trying to apply directory renames to paths within the given
directories, we want to make sure that there aren't conflicts at the
directory level. There will be additional checks at the individual
file level too, which will be added later.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This populates a set of directory renames for us. The set of directory
renames is not yet used, but will be in subsequent commits.
Note that the use of a string_list for possible_new_dirs in the new
dir_rename_entry struct implies an O(n^2) algorithm; however, in practice
I expect the number of distinct directories that files were renamed into
from a single original directory to be O(1). My guess is that n has a
mode of 1 and a mean of less than 2, so, for now, string_list seems good
enough for possible_new_dirs.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In d8193743e08 (usage.c: add BUG() function, 2017-05-12), a new macro
was introduced to use for reporting bugs instead of die(). It was then
subsequently used to convert one single caller in 588a538ae55
(setup_git_env: convert die("BUG") to BUG(), 2017-05-12).
The cover letter of the patch series containing this patch
(cf 20170513032414.mfrwabt4hovujde2@sigill.intra.peff.net) is not
terribly clear why only one call site was converted, or what the plan
is for other, similar calls to die() to report bugs.
Let's just convert all remaining ones in one fell swoop.
This trick was performed by this invocation:
sed -i 's/die("BUG: /BUG("/g' $(git grep -l 'die("BUG' \*.c)
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In anticipation of more involved cleanup to come, make a helper function
for doing the cleanup at the end of handle_renames. Rename the already
existing cleanup_rename[s]() to final_cleanup_rename[s](), name the new
helper initial_cleanup_rename(), and leave the big comment in the code
about why we can't do all the cleanup at once.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create a new function, get_diffpairs() to compute the diff_filepairs
between two trees. While these are currently only used in
get_renames(), I want them to be available to some new functions. No
actual logic changes yet.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Previously, if !o->detect_rename then get_renames() would return an
empty string_list, and then process_renames() would have nothing to
iterate over. It seems more straightforward to simply avoid calling
either function in that case.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
get_renames() has always zero'ed out diff_queued_diff.nr while only
manually free'ing diff_filepairs that did not correspond to renames.
Further, it allocated struct renames that were tucked away in the
return string_list. Make sure all of these are deallocated when we
are done with them.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The amount of logic in merge_trees() relative to renames was just a few
lines, but split it out into new handle_renames() and cleanup_renames()
functions to prepare for additional logic to be added to each. No code or
logic changes, just a new place to put stuff for when the rename detection
gains additional checks.
Note that process_renames() records pointers to various information (such
as diff_filepairs) into rename_conflict_info structs. Even though the
rename string_lists are not directly used once handle_renames() completes,
we should not immediately free the lists at the end of that function
because they store the information referenced in the rename_conflict_info,
which is used later in process_entry(). Thus the reason for a separate
cleanup_renames().
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move this function so it can re-use some others (without either
moving all of them or adding an annoying split between function
declarations and definitions). Cheat slightly by adding a blank line
for readability, and in order to silence checkpatch.pl.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reverts commit e4bb62fa1eeee689744b413e29a50b4d1dae6886, reversing
changes made to 468165c1d8a442994a825f3684528361727cd8c0.
The topic appears to inflict severe regression in renaming merges,
even though the promise of it was that it would improve them.
We do not yet know which exact change in the topic was wrong, but in
the meantime, let's play it safe and revert it out of 'master'
before real Git-using projects are harmed.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In anticipation of making trees load lazily, create a Coccinelle
script (contrib/coccinelle/commit.cocci) to ensure that all
references to the 'maybe_tree' member of struct commit are either
mutations or accesses through get_commit_tree() or
get_commit_tree_oid().
Apply the Coccinelle script to create the rest of the patch.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using the commit-graph file to walk commit history removes the large
cost of parsing commits during the walk. This exposes a performance
issue: lookup_tree() takes a large portion of the computation time,
even when Git never uses those trees.
In anticipation of lazy-loading these trees, rename the 'tree' member
of struct commit to 'maybe_tree'. This serves two purposes: it hints
at the future role of possibly being NULL even if the commit has a
valid tree, and it allows for unambiguous transformation from simple
member access (i.e. commit->maybe_tree) to method access.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Conversion from uchar[20] to struct object_id continues.
* bc/object-id: (36 commits)
convert: convert to struct object_id
sha1_file: introduce a constant for max header length
Convert lookup_replace_object to struct object_id
sha1_file: convert read_sha1_file to struct object_id
sha1_file: convert read_object_with_reference to object_id
tree-walk: convert tree entry functions to object_id
streaming: convert istream internals to struct object_id
tree-walk: convert get_tree_entry_follow_symlinks internals to object_id
builtin/notes: convert static functions to object_id
builtin/fmt-merge-msg: convert remaining code to object_id
sha1_file: convert sha1_object_info* to object_id
Convert remaining callers of sha1_object_info_extended to object_id
packfile: convert unpack_entry to struct object_id
sha1_file: convert retry_bad_packed_offset to struct object_id
sha1_file: convert assert_sha1_type to object_id
builtin/mktree: convert to struct object_id
streaming: convert open_istream to use struct object_id
sha1_file: convert check_sha1_signature to struct object_id
sha1_file: convert read_loose_object to use struct object_id
builtin/index-pack: convert struct ref_delta_entry to object_id
...
Rename detection logic in "diff" family that is used in "merge" has
learned to guess when all of x/a, x/b and x/c have moved to z/a,
z/b and z/c, it is likely that x/d added in the meantime would also
want to move to z/d by taking the hint that the entire directory
'x' moved to 'z'. A bug causing dirty files involved in a rename
to be overwritten during merge has also been fixed as part of this
work.
* en/rename-directory-detection: (29 commits)
merge-recursive: ensure we write updates for directory-renamed file
merge-recursive: avoid spurious rename/rename conflict from dir renames
directory rename detection: new testcases showcasing a pair of bugs
merge-recursive: fix remaining directory rename + dirty overwrite cases
merge-recursive: fix overwriting dirty files involved in renames
merge-recursive: avoid clobbering untracked files with directory renames
merge-recursive: apply necessary modifications for directory renames
merge-recursive: when comparing files, don't include trees
merge-recursive: check for file level conflicts then get new name
merge-recursive: add computation of collisions due to dir rename & merging
merge-recursive: check for directory level conflicts
merge-recursive: add get_directory_renames()
merge-recursive: make a helper function for cleanup for handle_renames
merge-recursive: split out code for determining diff_filepairs
merge-recursive: make !o->detect_rename codepath more obvious
merge-recursive: fix leaks of allocated renames and diff_filepairs
merge-recursive: introduce new functions to handle rename logic
merge-recursive: move the get_renames() function
directory rename detection: tests for handling overwriting dirty files
directory rename detection: tests for handling overwriting untracked files
...
The 'self-initialised' variables construct (ie <type> var = var;) has
been used to silence gcc '-W[maybe-]uninitialized' warnings. This has,
unfortunately, caused MSVC to issue 'uninitialized variable' warnings.
Also, using clang static analysis causes complaints about an 'Assigned
value is garbage or undefined'.
There are six such constructs in the current codebase. Only one of the
six causes gcc to issue a '-Wmaybe-uninitialized' warning (which will
be addressed elsewhere). The remaining five 'init-self' gcc workarounds
are noted below, along with the commit which introduced them:
1. builtin/rev-list.c: 'reaches' and 'all', see commit 457f08a030
("git-rev-list: add --bisect-vars option.", 2007-03-21).
2. merge-recursive.c:2064 'mrtree', see commit f120ae2a8e ("merge-
recursive.c: mrtree in merge() is not used before set", 2007-10-29).
3. fast-import.c:3023 'oe', see commit 85c62395b1 ("fast-import: let
importers retrieve blobs", 2010-11-28).
4. fast-import.c:3006 'oe', see commit 28c7b1f7b7 ("fast-import: add a
get-mark command", 2015-07-01).
Remove the 'self-initialised' variable constructs noted above.
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert read_sha1_file to take a pointer to struct object_id and rename
it read_object_file. Do the same for read_sha1_file_extended.
Convert one use in grep.c to use the new function without any other code
change, since the pointer being passed is a void pointer that is already
initialized with a pointer to struct object_id. Update the declaration
and definitions of the modified functions, and apply the following
semantic patch to convert the remaining callers:
@@
expression E1, E2, E3;
@@
- read_sha1_file(E1.hash, E2, E3)
+ read_object_file(&E1, E2, E3)
@@
expression E1, E2, E3;
@@
- read_sha1_file(E1->hash, E2, E3)
+ read_object_file(E1, E2, E3)
@@
expression E1, E2, E3, E4;
@@
- read_sha1_file_extended(E1.hash, E2, E3, E4)
+ read_object_file_extended(&E1, E2, E3, E4)
@@
expression E1, E2, E3, E4;
@@
- read_sha1_file_extended(E1->hash, E2, E3, E4)
+ read_object_file_extended(E1, E2, E3, E4)
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert get_tree_entry and find_tree_entry to take pointers to struct
object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the declaration and definition of strbuf_add_unique_abbrev to
make it take a pointer to struct object_id. Predeclare the struct in
strbuf.h, as cache.h includes strbuf.h before it declares the struct,
and otherwise the struct declaration would have the wrong scope.
Apply the following semantic patch, along with the standard object_id
transforms, to adjust the callers:
@@
expression E1, E2, E3;
@@
- strbuf_add_unique_abbrev(E1, E2.hash, E3);
+ strbuf_add_unique_abbrev(E1, &E2, E3);
@@
expression E1, E2, E3;
@@
- strbuf_add_unique_abbrev(E1, E2->hash, E3);
+ strbuf_add_unique_abbrev(E1, E2, E3);
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the callback functions for read_tree_recursive to take a pointer
to struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have several callers like
if (active_cache_changed && write_locked_index(...))
handle_error();
rollback_lock_file(...);
where the final rollback is needed because "!active_cache_changed"
shortcuts the if-expression. There are also a few variants of this,
including some if-else constructs that make it more clear when the
explicit rollback is really needed.
Teach `write_locked_index()` to take a new flag SKIP_IF_UNCHANGED and
simplify the callers. Leave the most complicated of the callers (in
builtin/update-index.c) unchanged. Rewriting it to use this new flag
would end up duplicating logic.
We could have made the new flag behave the other way round
("FORCE_WRITE"), but that could break existing users behind their backs.
Let's take the more conservative approach. We can still migrate existing
callers to use our new flag. Later we might even be able to flip the
default, possibly without entirely ignoring the risk to in-flight or
out-of-tree topics.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we return early, or if `active_cache_changed` is false, we forget to
roll back the lockfile.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a file is present in HEAD before the merge and the other side of the
merge does not modify that file, we try to avoid re-writing the file and
making it stat-dirty. However, when a file is present in HEAD before the
merge and was in a directory that was renamed by the other side of the
merge, we have to move the file to a new location and re-write it.
Update the code that checks whether we can skip the update to also work in
the presence of directory renames.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If a file on one side of history was renamed, and merely modified on the
other side, then applying a directory rename to the modified side gives us
a rename/rename(1to2) conflict. We should only apply directory renames to
pairs representing either adds or renames.
Making this change means that a directory rename testcase that was
previously reported as a rename/delete conflict will now be reported as a
modify/delete conflict.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This fixes an issue that existed before my directory rename detection
patches that affects both normal renames and renames implied by
directory rename detection. Additional codepaths that only affect
overwriting of dirty files that are involved in directory rename
detection will be added in a subsequent commit.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit hooks together all the directory rename logic by making the
necessary changes to the rename struct, it's dst_entry, and the
diff_filepair under consideration.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git merge -Xours/-Xtheirs" learned to use our/their version when
resolving a conflicting updates to a symbolic link.
* jc/merge-symlink-ours-theirs:
merge: teach -Xours/-Xtheirs to symbolic link merge
* en/merge-recursive-fixes:
merge-recursive: add explanation for src_entry and dst_entry
merge-recursive: fix logic ordering issue
Tighten and correct a few testcases for merging and cherry-picking
get_renames() would look up stage data that already existed (populated
in get_unmerged(), taken from whatever unpack_trees() created), and if
it didn't exist, would call insert_stage_data() to create the necessary
entry for the given file. The insert_stage_data() fallback becomes
much more important for directory rename detection, because that creates
a mechanism to have a file in the resulting merge that didn't exist on
either side of history. However, insert_stage_data(), due to calling
get_tree_entry() loaded up trees as readily as files. We aren't
interested in comparing trees to files; the D/F conflict handling is
done elsewhere. This code is just concerned with what entries existed
for a given path on the different sides of the merge, so create a
get_tree_entry_if_blob() helper function and use it.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before trying to apply directory renames to paths within the given
directories, we want to make sure that there aren't conflicts at the
file level either. If there aren't any, then get the new name from
any directory renames.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
directory renaming and merging can cause one or more files to be moved to
where an existing file is, or to cause several files to all be moved to
the same (otherwise vacant) location. Add checking and reporting for such
cases, falling back to no-directory-rename handling for such paths.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before trying to apply directory renames to paths within the given
directories, we want to make sure that there aren't conflicts at the
directory level. There will be additional checks at the individual
file level too, which will be added later.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This populates a set of directory renames for us. The set of directory
renames is not yet used, but will be in subsequent commits.
Note that the use of a string_list for possible_new_dirs in the new
dir_rename_entry struct implies an O(n^2) algorithm; however, in practice
I expect the number of distinct directories that files were renamed into
from a single original directory to be O(1). My guess is that n has a
mode of 1 and a mean of less than 2, so, for now, string_list seems good
enough for possible_new_dirs.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In anticipation of more involved cleanup to come, make a helper function
for doing the cleanup at the end of handle_renames. Rename the already
existing cleanup_rename[s]() to final_cleanup_rename[s](), name the new
helper initial_cleanup_rename(), and leave the big comment in the code
about why we can't do all the cleanup at once.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create a new function, get_diffpairs() to compute the diff_filepairs
between two trees. While these are currently only used in
get_renames(), I want them to be available to some new functions. No
actual logic changes yet.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Previously, if !o->detect_rename then get_renames() would return an
empty string_list, and then process_renames() would have nothing to
iterate over. It seems more straightforward to simply avoid calling
either function in that case.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
get_renames() has always zero'ed out diff_queued_diff.nr while only
manually free'ing diff_filepairs that did not correspond to renames.
Further, it allocated struct renames that were tucked away in the
return string_list. Make sure all of these are deallocated when we
are done with them.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The amount of logic in merge_trees() relative to renames was just a few
lines, but split it out into new handle_renames() and cleanup_renames()
functions to prepare for additional logic to be added to each. No code or
logic changes, just a new place to put stuff for when the rename detection
gains additional checks.
Note that process_renames() records pointers to various information (such
as diff_filepairs) into rename_conflict_info structs. Even though the
rename string_lists are not directly used once handle_renames() completes,
we should not immediately free the lists at the end of that function
because they store the information referenced in the rename_conflict_info,
which is used later in process_entry(). Thus the reason for a separate
cleanup_renames().
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move this function so it can re-use some others (without either
moving all of them or adding an annoying split between function
declarations and definitions). Cheat slightly by adding a blank line
for readability, and in order to silence checkpatch.pl.
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the definition and declaration of write_sha1_file to
struct object_id and adjust usage of this function.
This commit also converts static function write_sha1_file_prepare, as it
is closely related.
Rename these functions to write_object_file and
write_object_file_prepare respectively.
Replace sha1_to_hex, hashcpy and hashclr with their oid equivalents
wherever possible.
Signed-off-by: Patryk Obara <patryk.obara@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git merge -Xours/-Xtheirs" learned to use our/their version when
resolving a conflicting updates to a symbolic link.
* jc/merge-symlink-ours-theirs:
merge: teach -Xours/-Xtheirs to symbolic link merge
If I have to walk through the debugger and inspect the values found in
here in order to figure out their meaning, despite having known these
things inside and out some years back, then they probably need a comment
for the casual reader to explain their purpose.
Reviewed-By: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge_trees() did a variety of work, including:
* Calling get_unmerged() to get unmerged entries
* Calling record_df_conflict_files() with all unmerged entries to
do some work to ensure we could handle D/F conflicts correctly
* Calling get_renames() to check for renames.
An easily overlooked issue is that get_renames() can create more
unmerged entries and add them to the list, which have the possibility of
being involved in D/F conflicts. So the call to
record_df_conflict_files() should really be moved after all the rename
detection. I didn't come up with any testcases demonstrating any bugs
with the old ordering, but I suspect there were some for both normal
renames and for directory renames. Fix the ordering.
Reviewed-By: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When merging another branch into ours, if their tree is the same as
the common ancestor's, we can declare that our tree represents the
result of three-way merge. In such a case, the recursive merge
backend incorrectly used to create a commit out of our index, even
when the index has changes.
A recent fix attempted to prevent this by adding a comparison
between "our" tree and the index, but forgot that this check must be
restricted only to the outermost merge. Inner merges performed by
the recursive backend across merge bases are by definition made from
scratch without having any local changes added to the index. The
call to index_has_changes() during an inner merge is working on the
index that has no relation to the merge being performed, preventing
legitimate merges from getting carried out.
Fix it by limiting the check to the outermost merge.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The -Xours/-Xtheirs merge options were originally defined as a way
to "force" the resolution of 3way textual merge conflicts to take
one side without using your editor, hence did not even trigger in
situations where you would normally not get the <<< === >>> conflict
markers.
This was improved for binary files back in 2012 with a944af1d
("merge: teach -Xours/-Xtheirs to binary ll-merge driver",
2012-09-08).
Teach a similar trick to the codepath that deals with merging two
conflicting changes to symbolic links.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Tested-by: Yaroslav Halchenko <yoh@onerussian.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
