"git rerere" can encounter two or more files with the same conflict
signature that have to be resolved in different ways, but there was
no way to record these separate resolutions.
* jc/rerere-multi:
rerere: adjust 'forget' to multi-variant world order
rerere: split code to call ll_merge() further
rerere: move code related to "forget" together
rerere: gc and clear
rerere: do use multiple variants
t4200: rerere a merge with two identical conflicts
rerere: allow multiple variants to exist
rerere: delay the recording of preimage
rerere: handle leftover rr-cache/$ID directory and postimage files
rerere: scan $GIT_DIR/rr-cache/$ID when instantiating a rerere_id
rerere: split conflict ID further
The shape of the conflict in a path determines the conflict ID. The
preimage and postimage pair that was recorded for the conflict ID
previously may or may not replay well for the conflict we just saw.
Currently, we punt when the previous resolution does not cleanly
replay, but ideally we should then be able to record the currently
conflicted path by assigning a new 'variant', and then record the
resolution the user is going to make.
Introduce a mechanism to have more than one variant for a given
conflict ID; we do not actually assign any variant other than 0th
variant yet at this step.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The plan is to keep assigning the backward compatible conflict ID
based on the hash of the (normalized) text of conflicts, keep using
that conflict ID as the directory name under $GIT_DIR/rr-cache/, but
allow each conflicted path to use a separate "variant" to record
resolutions, i.e. having more than one <preimage,postimage> pairs
under $GIT_DIR/rr-cache/$ID/ directory. As the first step in that
direction, separate the shared "conflict ID" out of the rerere_id
structure.
The plan is to keep information per $ID in rerere_dir, that can be
shared among rerere_id that is per conflicted path.
When we are done with rerere(), which can be directly called from
other programs like "git apply", "git commit" and "git merge", the
shared rerere_dir structures can be freed entirely, so they are not
reference-counted and they are not freed when we release rerere_id's
that reference them.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up and minor fixes.
* jc/rerere: (21 commits)
rerere: un-nest merge() further
rerere: use "struct rerere_id" instead of "char *" for conflict ID
rerere: call conflict-ids IDs
rerere: further clarify do_rerere_one_path()
rerere: further de-dent do_plain_rerere()
rerere: refactor "replay" part of do_plain_rerere()
rerere: explain the remainder
rerere: explain "rerere forget" codepath
rerere: explain the primary codepath
rerere: explain MERGE_RR management helpers
rerere: fix benign off-by-one non-bug and clarify code
rerere: explain the rerere I/O abstraction
rerere: do not leak mmfile[] for a path with multiple stage #1 entries
rerere: stop looping unnecessarily
rerere: drop want_sp parameter from is_cmarker()
rerere: report autoupdated paths only after actually updating them
rerere: write out each record of MERGE_RR in one go
rerere: lift PATH_MAX limitation
rerere: plug conflict ID leaks
rerere: handle conflicts with multiple stage #1 entries
...
There's a bug in builtin/am.c in which we take a lock on
MERGE_RR recursively. But rather than fix am.c, this patch
fixes the confusing interface from rerere.c that caused the
bug. Read on for the gory details.
The setup_rerere() function both reads the existing MERGE_RR
file, and takes MERGE_RR.lock. In the rerere() and
rerere_forget() functions, we end up in write_rr(), which
will then commit the lock file.
But for functions like rerere_clear() that do not write to
MERGE_RR, we expect the caller to have handled
setup_rerere(). That caller would then need to release the
lockfile, but it can't; the lock struct is local to
rerere.c.
For builtin/rerere.c, this is OK. We run a single rerere
operation and then exit immediately, which has the side
effect of rolling back the lockfile.
But in builtin/am.c, this is actively wrong. If we run "git
am -3 --skip", we call setup-rerere twice without releasing
the lock:
1. The "--skip" causes us to call am_rerere_clear(), which
calls setup_rerere(), but never drops the lock.
2. We then proceed to the next patch.
3. The "--3way" may cause us to call rerere() to handle
conflicts in that patch, but we are already holding the
lock. The lockfile code dies with:
BUG: prepare_tempfile_object called for active object
We could fix this by having rerere_clear() call
rollback_lock_file(). But it feels a bit odd for it to roll
back a lockfile that it did not itself take. So let's
simplify the interface further, and handle setup_rerere in
the function itself, taking away the question from the
caller over whether they need to do so.
We can give rerere_gc() the same treatment, as well (even
though it doesn't have any callers besides builtin/rerere.c
at this point). Note that these functions don't take flags
from their callers to pass along to setup_rerere; that's OK,
because the flags would not be meaningful for what they are
doing.
Both of those functions need to hold the lock because even
though they do not write to MERGE_RR, they are still writing
and should be protected from a simultaneous "rerere" run.
But rerere_remaining(), "rerere diff", and "rerere status"
are all read-only operations. They want to setup_rerere(),
but do not care about taking the lock in the first place.
Since our update of MERGE_RR is the usual atomic rename done
by commit_lock_file, they can just do a lockless read. For
that, we teach setup_rerere a READONLY flag to avoid the
lock.
As a bonus, this pushes builtin/rerere.c's setup_rerere call
closer to the functions that use it. Which means that "git
rerere totally-bogus-command" will no longer silently
exit(0) in a repository without rerere enabled.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This gives a thin abstraction between the conflict ID that is a hash
value obtained by inspecting the conflicts and the name of the
directory under $GIT_DIR/rr-cache/, in which the previous resolution
is recorded to be replayed. The plan is to make sure that the
presence of the directory does not imply the presense of a previous
resolution and vice-versa, and later allow us to have more than one
pair of <preimage, postimage> for a given conflict ID.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most places we call conflict IDs "name" and some others we call them
"hex"; update all of them to "id".
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This moves the two features from builtin/rerere.c to a more library-ish
portion of the codebase. No behaviour change.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After "rerere" resolves conflicts by reusing old resolution, there would
be three kinds of paths with conflict in the index:
* paths that have been resolved in the working tree by rerere;
* paths that need further work whose resolution could be recorded;
* paths that need resolving that rerere won't help.
When the user wants a list of paths that need hand-resolving, output from
"rerere status" does not help, as it shows only the second category, but
the paths in the third category still needs work (rerere only makes sense
for regular files that have both our side and their side, and does not
help other kinds of conflicts, e.g. "we modified, they deleted").
The new subcommand "rerere remaining" can be used to show both. As
opposed to "rerere status", this subcommand also skips printing paths
that have been added to the index, since these paths are already
resolved and are no longer "remaining".
Initial patch provided by Junio. Refactored and modified to skip
resolved paths by Martin. Commit message mostly by Junio.
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jc/cache-unmerge:
rerere forget path: forget recorded resolution
rerere: refactor rerere logic to make it independent from I/O
rerere: remove silly 1024-byte line limit
resolve-undo: teach "update-index --unresolve" to use resolve-undo info
resolve-undo: "checkout -m path" uses resolve-undo information
resolve-undo: allow plumbing to clear the information
resolve-undo: basic tests
resolve-undo: record resolved conflicts in a new index extension section
builtin-merge.c: use standard active_cache macros
Conflicts:
builtin-ls-files.c
builtin-merge.c
builtin-rerere.c
After you find out an earlier resolution you told rerere to use was a
mismerge, there is no easy way to clear it. A new subcommand "forget" can
be used to tell git to forget a recorded resolution, so that you can redo
the merge from scratch.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a command line option to override rerere.autoupdate configuration
variable to make it more useful.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Both rerere.c and builtin-rerere.c define the static functions
rr_path() and has_resolution() the exact same way. To eliminate this
code duplication this patch turns the functions in rerere.c
non-static, and makes builtin-rerere.c use them. Also, since this
puts these two functions into the global namespace, rename them to
rerere_path() and has_rerere_resolution(), respectively, and rename
their "name" parameter to "hex", because it better reflects what that
parameter actually is.
Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The name path_list was correct for the first usage of that data structure,
but it really is a general-purpose string list.
$ perl -i -pe 's/path-list/string-list/g' $(git grep -l path-list)
$ perl -i -pe 's/path_list/string_list/g' $(git grep -l path_list)
$ git mv path-list.h string-list.h
$ git mv path-list.c string-list.c
$ perl -i -pe 's/has_path/has_string/g' $(git grep -l has_path)
$ perl -i -pe 's/path/string/g' string-list.[ch]
$ git mv Documentation/technical/api-path-list.txt \
Documentation/technical/api-string-list.txt
$ perl -i -pe 's/strdup_paths/strdup_strings/g' $(git grep -l strdup_paths)
... and then fix all users of string-list to access the member "string"
instead of "path".
Documentation/technical/api-string-list.txt needed some rewrapping, too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch moves rerere()-related functions into a newly created
rerere.c file.
The setup_rerere() function is needed by both rerere() and cmd_rerere(),
so this function is moved to rerere.c and declared non-static (and "extern")
in newly created rerere.h file.
Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
