This is copied from merge-recursive.c, with minor tweaks due to:
* using strmap API
* merge-ort not using the non_unique_new_dir field, since it'll
obviate its need entirely later with performance improvements
* adding a new path_in_way() function that uses opt->priv->paths
instead of doing an expensive tree_has_path() lookup to see if
a tree has a given path.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is copied from merge-recursive.c, with minor tweaks due to using strmap
API and the fact that it can use opt->priv->paths to get all pathnames that
exist instead of taking a tree object.
This depends on a new function, handle_path_level_conflicts(), which
just has a placeholder die-not-yet-implemented implementation for now; a
subsequent patch will implement it.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Both of these are copied from merge-recursive.c, with just minor tweaks
due to using strmap API and not having a non_unique_new_dir field.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is nearly a wholesale copy of compute_collisions() from
merge-recursive.c, and the logic remains the same, but it has been
tweaked slightly due to:
* using strmap.h API (instead of direct hashmaps)
* allocation/freeing of data structures were done separately in
merge_start() and clear_or_reinit_internal_opts() in an earlier
patch in this series
* there is no non_unique_new_dir data field in merge-ort; that will
be handled a different way
It does depend on two new functions, apply_dir_rename() and
check_dir_renamed() which were introduced with simple
die-not-yet-implemented shells and will be implemented in subsequent
patches.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
collect_renames() is similar to merge-recursive.c's get_renames(), but
lacks the directory rename handling found in the latter. Port that code
structure over to merge-ort. This introduces three new
die-not-yet-implemented functions that will be defined in future
commits.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is modelled on the version of handle_directory_level_conflicts()
from merge-recursive.c, but is massively simplified due to the following
factors:
* strmap API provides simplifications over using direct hashmap
* we have a dirs_removed field in struct rename_info that we have an
easy way to populate from collect_merge_info(); this was already
used in compute_rename_counts() and thus we do not need to check
for condition #2.
* The removal of condition #2 by handling it earlier in the code also
obviates the need to check for condition #3 -- if both sides renamed
a directory, meaning that the directory no longer exists on either
side, then neither side could have added any new files to that
directory, and thus there are no files whose locations we need to
move due to such a directory rename.
In fact, the same logic that makes condition #3 irrelevant means
condition #1 is also irrelevant so we could drop this function.
However, it is cheap to check if both sides rename the same directory,
and doing so can save future computation. So, simply remove any
directories that both sides renamed from the list of directory renames.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function is based on the first half of get_directory_renames() from
merge-recursive.c; as part of the implementation, factor out a routine,
increment_count(), to update the bookkeeping to track the number of
items renamed into new directories.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function is based on merge-recursive.c's get_directory_renames(),
except that the first half has been split out into a not-yet-implemented
compute_rename_counts(). The primary difference here is our lack of the
non_unique_new_dir boolean in our strmap. The lack of that field will
at first cause us to fail testcase 2b of t6423; however, future
optimizations will obviate the need for that ugly field so we have just
left it out.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Port some directory rename handling changes from merge-recursive.c's
detect_and_process_renames() to the same-named function of merge-ort.c.
This does not yet add any use or handling of directory renames, just the
outline for where we start to compute them. Thus, a future patch will
add port additional changes to merge-ort's detect_and_process_renames().
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement merge_incore_recursive(), mostly through the use of a new
helper function, merge_ort_internal(), which itself is based off
merge_recursive_internal() from merge-recursive.c.
This drops the number of failures in the testsuite when run under
GIT_TEST_MERGE_ALGORITHM=ort from around 1500 to 647.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to handle recursive merges, after merging merge-bases we need
to clear away most of the data we had built up but some of it needs to
be kept -- in particular the "output" field. Rename the function to
reflect its future change in use.
Further, since "reinitialize" means we'll be reusing the fields
immediately, take advantage of this to only partially clear maps,
leaving the hashtable allocated and pre-sized. (This may be slightly
out-of-order since the speedups aren't realized until there are far
more strmaps in use, but the patch submission process already went out
of order because of various questions and requests for strmap. Anyway,
see commit 6ccdfc2a20 ("strmap: enable faster clearing and reusing of
strmaps", 2020-11-05), for performance details about the use of
strmap_partial_clear().)
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a subsequent commit, we will implement the traditional recursiveness
that gave merge-recursive its name, namely merging non-unique
merge-bases to come up with a single virtual merge base. Copy a few
helper functions from merge-recursive.c that we will use in the
implementation.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement cases where renames are involved in type changes (i.e. the
side of history that didn't rename the file changed its type from a
regular file to a symlink or submodule). There was some code to handle
this in merge-recursive but only in the special case when the renamed
file had no content changes. The code here works differently -- it
knows process_entry() can handle mode conflicts, so it does a few
minimal tweaks to ensure process_entry() can just finish the job as
needed.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement handling of normal renames. This code replaces the following
from merge-recurisve.c:
* the code relevant to RENAME_NORMAL in process_renames()
* the RENAME_NORMAL case of process_entry()
Also, there is some shared code from merge-recursive.c for multiple
different rename cases which we will no longer need for this case (or
other rename cases):
* handle_rename_normal()
* setup_rename_conflict_info()
The consolidation of four separate codepaths into one is made possible
by a change in design: process_renames() tweaks the conflict_info
entries within opt->priv->paths such that process_entry() can then
handle all the non-rename conflict types (directory/file, modify/delete,
etc.) orthogonally. This means we're much less likely to miss special
implementation of some kind of combination of conflict types (see
commits brought in by 66c62eaec6 ("Merge branch 'en/merge-tests'",
2020-11-18), especially commit ef52778708 ("merge tests: expect improved
directory/file conflict handling in ort", 2020-10-26) for more details).
That, together with letting worktree/index updating be handled
orthogonally in the merge_switch_to_result() function, dramatically
simplifies the code for various special rename cases.
(To be fair, the code for handling normal renames wasn't all that
complicated beforehand, but it's still much simpler now.)
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement rename/rename(2to1) and rename/add handling, i.e. a file is
renamed into a location where another file is added (with that other
file either being a plain add or itself coming from a rename). Note
that rename collisions can also have a special case stacked on top: the
file being renamed on one side of history is deleted on the other
(yielding either a rename/add/delete conflict or perhaps a
rename/rename(2to1)/delete[/delete]) conflict.
One thing to note here is that when there is a double rename, the code
in question only handles one of them at a time; a later iteration
through the loop will handle the other. After they've both been
handled, process_entry()'s normal add/add code can handle the collision.
This code replaces the following from merge-recurisve.c:
* all the 2to1 code in process_renames()
* the RENAME_TWO_FILES_TO_ONE case of process_entry()
* handle_rename_rename_2to1()
* handle_rename_add()
Also, there is some shared code from merge-recursive.c for multiple
different rename cases which we will no longer need for this case (or
other rename cases):
* handle_file_collision()
* setup_rename_conflict_info()
The consolidation of six separate codepaths into one is made possible
by a change in design: process_renames() tweaks the conflict_info
entries within opt->priv->paths such that process_entry() can then
handle all the non-rename conflict types (directory/file, modify/delete,
etc.) orthogonally. This means we're much less likely to miss special
implementation of some kind of combination of conflict types (see
commits brought in by 66c62eaec6 ("Merge branch 'en/merge-tests'",
2020-11-18), especially commit ef52778708 ("merge tests: expect improved
directory/file conflict handling in ort", 2020-10-26) for more details).
That, together with letting worktree/index updating be handled
orthogonally in the merge_switch_to_result() function, dramatically
simplifies the code for various special rename cases.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement rename/delete conflicts, i.e. one side renames a file and the
other deletes the file. This code replaces the following from
merge-recurisve.c:
* the code relevant to RENAME_DELETE in process_renames()
* the RENAME_DELETE case of process_entry()
* handle_rename_delete()
Also, there is some shared code from merge-recursive.c for multiple
different rename cases which we will no longer need for this case (or
other rename cases):
* handle_change_delete()
* setup_rename_conflict_info()
The consolidation of five separate codepaths into one is made possible
by a change in design: process_renames() tweaks the conflict_info
entries within opt->priv->paths such that process_entry() can then
handle all the non-rename conflict types (directory/file, modify/delete,
etc.) orthogonally. This means we're much less likely to miss special
implementation of some kind of combination of conflict types (see
commits brought in by 66c62eaec6 ("Merge branch 'en/merge-tests'",
2020-11-18), especially commit ef52778708 ("merge tests: expect improved
directory/file conflict handling in ort", 2020-10-26) for more details).
That, together with letting worktree/index updating be handled
orthogonally in the merge_switch_to_result() function, dramatically
simplifies the code for various special rename cases.
To be fair, there is a _slight_ tweak to process_entry() here, because
rename/delete cases will also trigger the modify/delete codepath.
However, we only want a modify/delete message to be printed for a
rename/delete conflict if there is a content change in the renamed file
in addition to the rename. So process_renames() and process_entry()
aren't quite fully orthogonal, but they are pretty close.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement rename/rename(1to2) handling, i.e. both sides of history
renaming a file and rename it differently. This code replaces the
following from merge-recurisve.c:
* all the 1to2 code in process_renames()
* the RENAME_ONE_FILE_TO_TWO case of process_entry()
* handle_rename_rename_1to2()
Also, there is some shared code from merge-recursive.c for multiple
different rename cases which we will no longer need for this case (or
other rename cases):
* handle_file_collision()
* setup_rename_conflict_info()
The consolidation of five separate codepaths into one is made possible
by a change in design: process_renames() tweaks the conflict_info
entries within opt->priv->paths such that process_entry() can then
handle all the non-rename conflict types (directory/file, modify/delete,
etc.) orthogonally. This means we're much less likely to miss special
implementation of some kind of combination of conflict types (see
commits brought in by 66c62eaec6 ("Merge branch 'en/merge-tests'",
2020-11-18), especially commit ef52778708 ("merge tests: expect improved
directory/file conflict handling in ort", 2020-10-26) for more details).
That, together with letting worktree/index updating be handled
orthogonally in the merge_switch_to_result() function, dramatically
simplifies the code for various special rename cases.
To be fair, there is a _slight_ tweak to process_entry() here to make
sure that the two different paths aren't marked as clean but are left in
a conflicted state. So process_renames() and process_entry() aren't
quite entirely orthogonal, but they are pretty close.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement rename/rename(1to1) handling, i.e. both sides of history
renaming a file but renaming the same way. This code replaces the
following from merge-recurisve.c:
* all the 1to1 code in process_renames()
* the RENAME_ONE_FILE_TO_ONE case of process_entry()
Also, there is some shared code from merge-recursive.c for multiple
different rename cases which we will no longer need for this case (or
other rename cases):
* handle_rename_normal()
* setup_rename_conflict_info()
The consolidation of four separate codepaths into one is made possible
by a change in design: process_renames() tweaks the conflict_info
entries within opt->priv->paths such that process_entry() can then
handle all the non-rename conflict types (directory/file, modify/delete,
etc.) orthogonally. This means we're much less likely to miss special
implementation of some kind of combination of conflict types (see
commits brought in by 66c62eaec6 ("Merge branch 'en/merge-tests'",
2020-11-18), especially commit ef52778708 ("merge tests: expect improved
directory/file conflict handling in ort", 2020-10-26) for more details).
That, together with letting worktree/index updating be handled
orthogonally in the merge_switch_to_result() function, dramatically
simplifies the code for various special rename cases.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add code which determines which kind of special rename case each rename
corresponds to, but leave the handling of each type unimplemented for
now. Future commits will implement each one.
There is some tenuous resemblance to merge-recursive's
process_renames(), but comparing the two is very unlikely to yield any
insights. merge-ort's process_renames() is a bit complex and I would
prefer if I could simplify it more, but it is far easier to grok than
merge-recursive's function of the same name in my opinion. Plus,
merge-ort handles more rename conflict types than merge-recursive does.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Based heavily on merge-recursive's get_diffpairs() function, and also
includes the necessary paired call to diff_warn_rename_limit() so that
users will be warned if merge.renameLimit is not sufficiently large for
rename detection to run.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This will grow later, but we only need a few fields for basic rename
handling.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The focus here is on adding a path_msg() which will queue up
warning/conflict/notice messages about the merge for later processing,
storing these in a pathname -> strbuf map. It might seem like a big
change, but it really just is:
* declaration of necessary map with some comments
* initialization and recording of data
* a bunch of code to iterate over the map at print/free time
* at least one caller in order to avoid an error about having an
unused function (which we provide in the form of implementing
modify/delete conflict handling).
At this stage, it is probably not clear why I am opting for delayed
output processing. There are multiple reasons:
1. Merges are supposed to abort if they would overwrite dirty changes
in the working tree. We cannot correctly determine whether changes
would be overwritten until both rename detection has occurred and
full processing of entries with the renames has finalized.
Warning/conflict/notice messages come up at intermediate codepaths
along the way, so unless we want spurious conflict/warning messages
being printed when the merge will be aborted anyway, we need to
save these messages and only print them when relevant.
2. There can be multiple messages for a single path, and we want all
messages for a give path to appear together instead of having them
grouped by conflict/warning type. This was a problem already with
merge-recursive.c but became even more important due to the
splitting apart of conflict types as discussed in the commit
message for 1f3c9ba707 ("t6425: be more flexible with rename/delete
conflict messages", 2020-08-10)
3. Some callers might want to avoid showing the output in certain
cases, such as if the end result is a clean merge. Rebases have
typically done this.
4. Some callers might not want the output to go to stdout or even
stderr, but might want to do something else with it entirely.
For example, a --remerge-diff option to `git show` or `git log
-p` that remerges on the fly and diffs merge commits against the
remerged version would benefit from stdout/stderr not being
written to in the standard form.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This simplistic and weird-looking patch is here to facilitate future
patch submissions. Adding this stub allows rename detection code to
reference it in one patch series, while a separate patch series can
define the implementation, and then both series can merge cleanly and
work nicely together at that point.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit b658536f59 ("merge-ort: add some high-level algorithm structure",
2020-10-27) added high-level structure of the ort merge algorithm. As
we have added more and more functions, that high-level structure has
been slightly obscured. Since functions are still grouped according to
this high-level structure, add comments denoting sections where all the
functions are specifically tied to a piece of the high-level structure.
This function groupings include a few sub-divisions of the original
high-level structure, including some sub-divisions that are yet to be
submitted. Each has (or will have) several functions all serving as
helpers to one or two main functions for each section.
As an added bonus, the comments will serve to provide a small textual
separation between nearby sections and allow the next three patch series
to be submitted independently and merge cleanly.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This field will be used in future patches to allow removal of paths from
opt->priv->paths.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This field is not yet used, but will be used by both the rename handling
code, and the conflict type handling code in process_entry().
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move most of merge_finalize() into a new helper function,
clear_internal_opts(). This is a step to facilitate recursive merges,
as well as some future optimizations.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Include blob.h for definition of blob_type, and commit-reach.h for
declarations of get_merge_bases() and in_merge_bases(). While none of
these are used yet, we want to avoid cross-dependencies in the next
three series of patches for merge-ort and merge them at the end; adding
these "#include"s now avoids textual conflicts.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After checkout(), the working tree has the appropriate contents, and the
index matches the working copy. That means that all unmodified and
cleanly merged files have correct index entries, but conflicted entries
need to be updated.
We do this by looping over the conflicted entries, marking the existing
index entry for the path with CE_REMOVE, adding new higher order staged
for the path at the end of the index (ignoring normal index sort order),
and then at the end of the loop removing the CE_REMOVED-marked cache
entries and sorting the index.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since merge-ort creates a tree for its output, when there are no
conflicts, updating the working tree and index is as simple as using the
unpack_trees() machinery with a twoway_merge (i.e. doing the equivalent
of a "checkout" operation).
If there were conflicts in the merge, then since the tree we created
included all the conflict markers, then using the unpack_trees machinery
in this manner will still update the working tree correctly. Further,
all index entries corresponding to cleanly merged files will also be
updated correctly by this procedure. Index entries corresponding to
conflicted entries will appear as though the user had run "git add -u"
after the merge to accept all files as-is with conflict markers.
Thus, after running unpack_trees(), there needs to be a separate step
for updating the entries in the index corresponding to conflicted files.
This will be the job for the function record_conflicted_index_entris(),
which will be implemented in a subsequent commit.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This adds a basic implementation for merge_switch_to_result(), though
just in terms of a few new empty functions that will be defined in
subsequent commits.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our order for processing of entries means that if we have a tree of
files that looks like
Makefile
src/moduleA/foo.c
src/moduleA/bar.c
src/moduleB/baz.c
src/moduleB/umm.c
tokens.txt
Then we will process paths in the order of the leftmost column below. I
have added two additional columns that help explain the algorithm that
follows; the 2nd column is there to remind us we have oid & mode info we
are tracking for each of these paths (which differs between the paths
which I'm not representing well here), and the third column annotates
the parent directory of the entry:
tokens.txt <version_info> ""
src/moduleB/umm.c <version_info> src/moduleB
src/moduleB/baz.c <version_info> src/moduleB
src/moduleB <version_info> src
src/moduleA/foo.c <version_info> src/moduleA
src/moduleA/bar.c <version_info> src/moduleA
src/moduleA <version_info> src
src <version_info> ""
Makefile <version_info> ""
When the parent directory changes, if it's a subdirectory of the previous
parent directory (e.g. "" -> src/moduleB) then we can just keep appending.
If the parent directory differs from the previous parent directory and is
not a subdirectory, then we should process that directory.
So, for example, when we get to this point:
tokens.txt <version_info> ""
src/moduleB/umm.c <version_info> src/moduleB
src/moduleB/baz.c <version_info> src/moduleB
and note that the next entry (src/moduleB) has a different parent than
the last one that isn't a subdirectory, we should write out a tree for it
100644 blob <HASH> umm.c
100644 blob <HASH> baz.c
then pop all the entries under that directory while recording the new
hash for that directory, leaving us with
tokens.txt <version_info> ""
src/moduleB <new version_info> src
This process repeats until at the end we get to
tokens.txt <version_info> ""
src <new version_info> ""
Makefile <version_info> ""
and then we can write out the toplevel tree. Since we potentially have
entries in our string_list corresponding to multiple different toplevel
directories, e.g. a slightly different repository might have:
whizbang.txt <version_info> ""
tokens.txt <version_info> ""
src/moduleD <new version_info> src
src/moduleC <new version_info> src
src/moduleB <new version_info> src
src/moduleA/foo.c <version_info> src/moduleA
src/moduleA/bar.c <version_info> src/moduleA
When src/moduleA is popped off, we need to know that the "last
directory" reverts back to src, and how many entries in our string_list
are associated with that parent directory. So I use an auxiliary
offsets string_list which would have (parent_directory,offset)
information of the form
"" 0
src 2
src/moduleA 5
Whenever I write out a tree for a subdirectory, I set versions.nr to
the final offset value and then decrement offsets.nr...and then add
an entry to versions with a hash for the new directory.
The idea is relatively simple, there's just a lot of accounting to
implement this.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create a new function, write_tree(), which will take a list of
basenames, modes, and oids for a single directory and create a tree
object in the object-store. We do not yet have just basenames, modes,
and oids for just a single directory (we have a mixture of entries from
all directory levels in the hierarchy) so we still die() before the
current call to write_tree(), but the next patch will rectify that.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As a step towards transforming the processed path->conflict_info entries
into an actual tree object, start recording basenames, modes, and oids
in a dir_metadata structure. Subsequent commits will make use of this
to actually write a tree.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We want to handle paths below a directory before needing to handle the
directory itself. Also, we want to handle the directory immediately
after the paths below it, so we can't use simple lexicographic ordering
from strcmp (which would insert foo.txt between foo and foo/file.c).
Copy string_list_df_name_compare() from merge-recursive.c, and set up a
string list of paths sorted by that function so that we can iterate in
the desired order.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a process_entries() implementation that just loops over the paths
and processes each one individually with an auxiliary process_entry()
call. Add a basic process_entry() as well, which handles several cases
but leaves a few of the more involved ones with die-not-implemented
messages. Also, although process_entries() is supposed to create a
tree, it does not yet have code to do so -- except in the special case
of merging completely empty trees.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When all three trees have the same oid, there is no need to recurse into
these trees to find that all files within them happen to match. We can
just record any one of the trees as the resolution of merging that
particular path.
Immediately resolving trees for other types of trivial tree merges (such
as one side matches the merge base, or the two sides match each other)
would prevent us from detecting renames for some paths, and thus prevent
us from doing three-way content merges for those paths whose renames we
did not detect.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create a helper function, setup_path_info(), which can be used to record
all the information we want in a merged_info or conflict_info. While
there is currently only one caller of this new function, and some of its
particular parameters are fixed, future callers of this function will be
added later.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Three-way merges, by their nature, are going to often have two or more
trees match at a given subdirectory. We can avoid calling
fill_tree_descriptor() on the same tree by checking when these trees
match. Noting when various oids match will also be useful in other
calculations and optimizations as well.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This does not actually collect any necessary info other than the
pathnames involved, since it just allocates an all-zero conflict_info
and stuffs that into paths. However, it invokes the traverse_trees()
machinery to walk over all the paths and sets up the basic
infrastructure we need.
I have left out a few obvious optimizations to try to make this patch as
short and obvious as possible. A subsequent patch will add some of
those back in with some more useful data fields before we introduce a
patch that actually sets up the conflict_info fields.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Various places in merge-recursive used an err() function when it hit
some kind of unrecoverable error. That code was from the reusable bits
of merge-recursive.c that we liked, such as merge_3way, writing object
files to the object store, reading blobs from the object store, etc. So
create a similar function to allow us to port that code over, and use it
for when we detect problems returned from collect_merge_info()'s
traverse_trees() call, which we will be adding next.
While we are at it, also add more documentation for the "clean" field
from struct merge_result, particularly since the name suggests a boolean
but it is not quite one and this is our first non-boolean usage.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
