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Elijah Newren 2fd9eda462 merge-ort: precompute whether directory rename detection is needed
The point of directory rename detection is that if one side of history
renames a directory, and the other side adds new files under the old
directory, then the merge can move those new files into the new
directory.  This leads to the following important observation:

  * If the other side does not add any new files under the old
    directory, we do not need to detect any renames for that directory.

Similarly, directory rename detection had an important requirement:

  * If a directory still exists on one side of history, it has not been
    renamed on that side of history.  (See section 4 of t6423 or
    Documentation/technical/directory-rename-detection.txt for more
    details).

Using these two bits of information, we note that directory rename
detection is only needed in cases where (1) directories exist in the
merge base and on one side of history (i.e. dirmask == 3 or dirmask ==
5), and (2) where there is some new file added to that directory on the
side where it still exists (thus where the file has filemask == 2 or
filemask == 4, respectively).  This has to be done in two steps, because
we have the dirmask when we are first considering the directory, and
won't get the filemasks for the files within it until we recurse into
that directory.  So, we save
  dir_rename_mask = dirmask - 1
when we hit a directory that is missing on one side, and then later look
for cases of
  filemask == dir_rename_mask

One final note is that as soon as we hit a directory that needs
directory rename detection, we will need to detect renames in all
subdirectories of that directory as well due to the "majority rules"
decision when files are renamed into different directory hierarchies.
We arbitrarily use the special value of 0x07 to record when we've hit
such a directory.

The combination of all the above mean that we introduce a variable
named dir_rename_mask (couldn't think of a better name) which has one
of the following values as we traverse into a directory:
   * 0x00: directory rename detection not needed
   * 0x02 or 0x04: directory rename detection only needed if files added
   * 0x07: directory rename detection definitely needed

We then pass this value through to add_pairs() so that it can mark
location_relevant as true only when dir_rename_mask is 0x07.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-10 22:18:05 -08:00
.github Merge branch 'tb/ci-run-cocci-with-18.04' into maint 2021-02-11 13:57:36 -08:00
Documentation diffcore-rename: use directory rename guided basename comparisons 2021-02-26 17:53:11 -08:00
block-sha1
builtin Merge branch 'ds/more-index-cleanups' 2021-02-10 14:48:33 -08:00
ci Merge branch 'ab/detox-gettext-tests' 2021-02-10 14:48:33 -08:00
compat Merge branch 'da/vs-build-iconv-fix' 2020-12-14 10:21:38 -08:00
contrib Remove support for v1 of the PCRE library 2021-01-23 21:15:43 -08:00
ewah bitmap: implement bitmap_is_subset() 2020-12-08 14:48:16 -08:00
git-gui Merge https://github.com/prati0100/git-gui 2020-12-18 15:07:10 -08:00
gitk-git
gitweb gitweb/Makefile: conditionally include ../GIT-VERSION-FILE 2020-12-08 16:56:56 -08:00
mergetools Merge branch 'pd/mergetool-nvimdiff' 2020-11-21 15:14:39 -08:00
negotiator
perl
po tests: remove support for GIT_TEST_GETTEXT_POISON 2021-01-21 15:50:01 -08:00
ppc
refs refs/files-backend: don't peek into `struct lock_file` 2021-01-06 13:53:32 -08:00
sha1collisiondetection@855827c583
sha1dc
sha256
t merge-ort: precompute subset of sources for which we need rename detection 2021-03-10 22:18:04 -08:00
templates
trace2
vcs-svn
xdiff
.cirrus.yml
.clang-format
.editorconfig
.gitattributes CoC: explicitly take any whitespace breakage 2021-01-04 09:44:49 -08:00
.gitignore Merge branch 'fc/random-cleanup' 2020-12-08 15:11:21 -08:00
.gitmodules
.mailmap
.travis.yml ci: remove GETTEXT_POISON jobs 2021-01-21 15:50:00 -08:00
.tsan-suppressions
CODE_OF_CONDUCT.md CoC: update to version 2.0 + local changes 2021-01-13 17:45:04 -08:00
COPYING
GIT-VERSION-GEN Git 2.30.1 2021-02-08 14:05:55 -08:00
INSTALL doc: mention Python 3.x supports 2020-12-14 15:01:03 -08:00
LGPL-2.1
Makefile Merge branch 'ab/grep-pcre-invalid-utf8' 2021-02-10 14:48:33 -08:00
README.md
RelNotes Prepare for 2.30.1 2021-02-05 16:31:28 -08:00
abspath.c abspath: add a function to resolve paths with missing components 2020-12-12 23:35:47 -08:00
aclocal.m4
add-interactive.c Merge branch 'js/add-i-color-fix' 2020-12-08 15:11:17 -08:00
add-interactive.h
add-patch.c Merge branch 'js/add-i-color-fix' 2020-12-08 15:11:17 -08:00
advice.c
advice.h
alias.c
alias.h
alloc.c
alloc.h
apply.c Merge branch 'ab/unreachable-break' 2020-12-18 15:15:18 -08:00
apply.h
archive-tar.c
archive-zip.c
archive.c Merge branch 'rs/archive-plug-leak-refname' 2020-11-25 15:24:53 -08:00
archive.h Merge branch 'rs/archive-plug-leak-refname' 2020-11-25 15:24:53 -08:00
attr.c
attr.h
banned.h banned.h: mark ctime_r() and asctime_r() as banned 2020-12-02 14:30:39 -08:00
base85.c
bisect.c hash-lookup: rename from sha1-lookup 2021-01-04 13:01:55 -08:00
bisect.h
blame.c Merge branch 'en/strmap' 2020-11-21 15:14:38 -08:00
blame.h
blob.c
blob.h
bloom.c
bloom.h
branch.c
branch.h
builtin.h
bulk-checkin.c
bulk-checkin.h
bundle.c bundle: arguments can be read from stdin 2021-01-11 21:50:41 -08:00
bundle.h
cache-tree.c cache-tree: extract subtree_pos() 2021-01-23 17:14:07 -08:00
cache-tree.h cache-tree: extract subtree_pos() 2021-01-23 17:14:07 -08:00
cache.h Merge branch 'ds/more-index-cleanups' 2021-02-10 14:48:33 -08:00
chdir-notify.c
chdir-notify.h
check-builtins.sh
check_bindir
checkout.c
checkout.h
color.c
color.h
column.c
column.h
combine-diff.c
command-list.txt mailmap doc: create a new "gitmailmap(5)" man page 2021-01-12 14:04:39 -08:00
commit-graph.c Merge branch 'jk/use-oid-pos' 2021-02-10 14:48:31 -08:00
commit-graph.h
commit-reach.c
commit-reach.h
commit-slab-decl.h
commit-slab-impl.h
commit-slab.h
commit.c oid_pos(): access table through const pointers 2021-01-28 12:03:26 -08:00
commit.h commit_graft_pos(): take an oid instead of a bare hash 2021-01-28 11:21:07 -08:00
common-main.c
config.c Merge branch 'ab/detox-gettext-tests' 2021-02-10 14:48:33 -08:00
config.h Merge branch 'ps/config-env-pairs' 2021-01-25 14:19:19 -08:00
config.mak.dev
config.mak.in
config.mak.uname config.mak.uname: remove redundant NO_LIBPCRE1_JIT flag 2021-01-23 21:15:12 -08:00
configure.ac Remove support for v1 of the PCRE library 2021-01-23 21:15:43 -08:00
connect.c Merge branch 'jk/forbid-lf-in-git-url' into maint 2021-02-05 16:31:27 -08:00
connect.h
connected.c
connected.h
convert.c
convert.h
copy.c
credential.c
credential.h
csum-file.c
csum-file.h
ctype.c
daemon.c
date.c
decorate.c
decorate.h
delta-islands.c
delta-islands.h
delta.h
detect-compiler
diff-delta.c
diff-lib.c Merge branch 'rs/plug-diff-cache-leak' 2020-11-25 15:24:53 -08:00
diff-merges.c diff-merges: add '--diff-merges=1' as synonym for 'first-parent' 2020-12-21 13:47:32 -08:00
diff-merges.h diff-merges: get rid of now empty diff_merges_init_revs() 2020-12-21 13:47:31 -08:00
diff-no-index.c
diff.c Merge branch 'sj/untracked-files-in-submodule-directory-is-not-dirty' 2021-01-25 14:19:18 -08:00
diff.h Merge branch 'sj/untracked-files-in-submodule-directory-is-not-dirty' 2021-01-25 14:19:18 -08:00
diffcore-break.c
diffcore-delta.c
diffcore-order.c
diffcore-pickaxe.c
diffcore-rename.c diffcore-rename: enable filtering possible rename sources 2021-03-10 22:18:04 -08:00
diffcore.h diffcore-rename: enable filtering possible rename sources 2021-03-10 22:18:04 -08:00
dir-iterator.c
dir-iterator.h
dir.c sparse-checkout: load sparse-checkout patterns 2021-01-23 17:14:07 -08:00
dir.h sparse-checkout: load sparse-checkout patterns 2021-01-23 17:14:07 -08:00
editor.c
entry.c
environment.c config: allow specifying config entries via envvar pairs 2021-01-15 13:03:45 -08:00
environment.h environment: make `getenv_safe()` a public function 2021-01-15 13:03:45 -08:00
exec-cmd.c
exec-cmd.h
fetch-negotiator.c
fetch-negotiator.h
fetch-pack.c fetch-pack: refactor writing promisor file 2021-01-12 16:01:07 -08:00
fetch-pack.h
fmt-merge-msg.c Merge branch 'so/log-diff-merge' 2021-02-05 16:40:44 -08:00
fmt-merge-msg.h
fsck.c Merge branch 'jk/forbid-lf-in-git-url' into maint 2021-02-05 16:31:27 -08:00
fsck.h fsck: make fsck_config() re-usable 2021-01-05 14:58:29 -08:00
fsmonitor.c fsmonitor: de-duplicate BUG()s around dirty bits 2021-01-23 17:14:07 -08:00
fsmonitor.h
fuzz-commit-graph.c
fuzz-pack-headers.c
fuzz-pack-idx.c
generate-cmdlist.sh
generate-configlist.sh
gettext.c Merge branch 'ab/detox-gettext-tests' 2021-02-10 14:48:33 -08:00
gettext.h tests: remove support for GIT_TEST_GETTEXT_POISON 2021-01-21 15:50:01 -08:00
git-add--interactive.perl Merge branch 'js/add-i-color-fix' 2020-12-08 15:11:17 -08:00
git-archimport.perl
git-bisect.sh
git-compat-util.h git-compat-util: always enable variadic macros 2021-01-27 22:14:37 -08:00
git-cvsexportcommit.perl
git-cvsimport.perl
git-cvsserver.perl
git-difftool--helper.sh
git-filter-branch.sh
git-instaweb.sh
git-merge-octopus.sh
git-merge-one-file.sh
git-merge-resolve.sh
git-mergetool--lib.sh Merge branch 'pb/mergetool-tool-help-fix' into maint 2021-02-05 16:31:24 -08:00
git-mergetool.sh
git-p4.py Merge branch 'dl/p4-encode-after-kw-expansion' into maint 2021-02-08 14:05:54 -08:00
git-quiltimport.sh
git-rebase--preserve-merges.sh
git-request-pull.sh
git-send-email.perl
git-sh-i18n.sh tests: remove support for GIT_TEST_GETTEXT_POISON 2021-01-21 15:50:01 -08:00
git-sh-setup.sh
git-submodule.sh submodule: fix fetch_in_submodule logic 2020-11-24 13:14:09 -08:00
git-svn.perl
git-web--browse.sh
git.c Merge branch 'ps/config-env-pairs' 2021-01-25 14:19:19 -08:00
git.rc
gpg-interface.c
gpg-interface.h
graph.c
graph.h
grep.c Merge branch 'ab/grep-pcre-invalid-utf8' 2021-02-10 14:48:33 -08:00
grep.h Merge branch 'ab/grep-pcre-invalid-utf8' 2021-02-10 14:48:33 -08:00
hash-lookup.c oid_pos(): access table through const pointers 2021-01-28 12:03:26 -08:00
hash-lookup.h oid_pos(): access table through const pointers 2021-01-28 12:03:26 -08:00
hash.h cache.h: move hash/oid functions to hash.h 2020-12-04 13:55:14 -08:00
hashmap.c
hashmap.h
help.c help.c: help.autocorrect=never means "do not compute suggestions" 2020-11-25 13:02:15 -08:00
help.h
hex.c
http-backend.c
http-fetch.c
http-push.c
http-walker.c
http.c
http.h
ident.c
imap-send.c imap-send: parse default git config 2020-12-01 11:10:59 -08:00
iterator.h
json-writer.c
json-writer.h
khash.h
kwset.c
kwset.h
levenshtein.c
levenshtein.h
line-log.c
line-log.h
line-range.c
line-range.h
linear-assignment.c
linear-assignment.h
list-objects-filter-options.c
list-objects-filter-options.h
list-objects-filter.c object-name.c: rename from sha1-name.c 2021-01-04 13:01:55 -08:00
list-objects-filter.h
list-objects.c
list-objects.h
list.h
ll-merge.c
ll-merge.h
lockfile.c
lockfile.h
log-tree.c Merge branch 'so/log-diff-merge' 2021-02-05 16:40:44 -08:00
log-tree.h
ls-refs.c Merge branch 'tb/ls-refs-optim' 2021-02-05 16:40:45 -08:00
ls-refs.h
mailinfo.c
mailinfo.h
mailmap.c shortlog: remove unused(?) "repo-abbrev" feature 2021-01-12 14:04:42 -08:00
mailmap.h shortlog: remove unused(?) "repo-abbrev" feature 2021-01-12 14:04:42 -08:00
match-trees.c
mem-pool.c
mem-pool.h
merge-blobs.c
merge-blobs.h
merge-ort-wrappers.c
merge-ort-wrappers.h
merge-ort.c merge-ort: precompute whether directory rename detection is needed 2021-03-10 22:18:05 -08:00
merge-ort.h merge-ort: implement merge_incore_recursive() 2020-12-16 21:56:39 -08:00
merge-recursive.c commit: move reverse_commit_list() from merge-recursive 2020-12-16 21:56:39 -08:00
merge-recursive.h
merge.c
mergesort.c
mergesort.h
midx.c Merge branch 'ma/more-opaque-lock-file' 2021-01-25 14:19:17 -08:00
midx.h
name-hash.c name-hash: use trace2 regions for init 2021-01-23 17:14:07 -08:00
notes-cache.c
notes-cache.h
notes-merge.c
notes-merge.h
notes-utils.c
notes-utils.h
notes.c Merge branch 'na/notes-displayref-is-not-boolean' 2020-11-30 14:49:44 -08:00
notes.h
object-file.c hash-lookup: rename from sha1-lookup 2021-01-04 13:01:55 -08:00
object-name.c object-name.c: rename from sha1-name.c 2021-01-04 13:01:55 -08:00
object-store.h
object.c bundle: lost objects when removing duplicate pendings 2021-01-11 21:50:41 -08:00
object.h
oid-array.c oid_pos(): access table through const pointers 2021-01-28 12:03:26 -08:00
oid-array.h oid-array: provide a for-loop iterator 2020-12-07 12:32:04 -08:00
oidmap.c
oidmap.h
oidset.c
oidset.h
pack-bitmap-write.c oid_pos(): access table through const pointers 2021-01-28 12:03:26 -08:00
pack-bitmap.c rebuild_existing_bitmaps(): convert to new revindex API 2021-01-13 21:53:46 -08:00
pack-bitmap.h pack-bitmap: factor out 'bitmap_for_commit()' 2020-12-08 14:49:04 -08:00
pack-check.c
pack-objects.c
pack-objects.h
pack-revindex.c pack-revindex.c: avoid direct revindex access in 'offset_to_pack_pos()' 2021-01-13 21:53:48 -08:00
pack-revindex.h pack-revindex: hide the definition of 'revindex_entry' 2021-01-13 21:53:48 -08:00
pack-write.c pack-write: die on error in write_promisor_file() 2021-01-14 17:02:22 -08:00
pack.h fetch-pack: refactor writing promisor file 2021-01-12 16:01:07 -08:00
packfile.c Merge branch 'tb/pack-revindex-api' 2021-01-25 14:19:20 -08:00
packfile.h
pager.c
parse-options-cb.c
parse-options.c
parse-options.h parse-options: format argh like error messages 2021-01-06 15:10:27 -08:00
patch-delta.c
patch-ids.c Merge branch 'jk/log-cherry-pick-duplicate-patches' into maint 2021-02-05 16:31:28 -08:00
patch-ids.h patch-ids: handle duplicate hashmap entries 2021-01-12 11:13:32 -08:00
path.c
path.h
pathspec.c
pathspec.h
pkt-line.c
pkt-line.h
preload-index.c
pretty.c pretty: lazy-load commit data when expanding user-format 2021-01-28 14:07:35 -08:00
pretty.h
prio-queue.c
prio-queue.h
progress.c
progress.h
promisor-remote.c
promisor-remote.h
prompt.c
prompt.h
protocol.c
protocol.h
prune-packed.c
prune-packed.h
quote.c quote: make sq_dequote_step() a public function 2021-01-12 12:03:18 -08:00
quote.h quote: make sq_dequote_step() a public function 2021-01-12 12:03:18 -08:00
range-diff.c
range-diff.h
reachable.c
reachable.h
read-cache.c read-cache: try not to peek into `struct {lock_,temp}file` 2021-01-06 13:53:32 -08:00
rebase-interactive.c
rebase-interactive.h
rebase.c
rebase.h
ref-filter.c Merge branch 'tb/ls-refs-optim' 2021-02-05 16:40:45 -08:00
ref-filter.h branch: sort detached HEAD based on a flag 2021-01-07 15:13:21 -08:00
reflog-walk.c
reflog-walk.h
refs.c Merge branch 'tb/ls-refs-optim' 2021-02-05 16:40:45 -08:00
refs.h Merge branch 'tb/ls-refs-optim' 2021-02-05 16:40:45 -08:00
refspec.c Merge branch 'fc/atmark-in-refspec' 2020-12-14 10:21:36 -08:00
refspec.h
remote-curl.c
remote.c Merge branch 'nk/refspecs-negative-fix' 2020-12-23 13:59:46 -08:00
remote.h fetch: extract writing to FETCH_HEAD 2021-01-12 12:06:14 -08:00
replace-object.c
replace-object.h
repo-settings.c
repository.c repository: add repo reference to index_state 2021-01-23 17:14:07 -08:00
repository.h
rerere.c rerere: use strmap to store rerere directories 2021-01-28 11:26:20 -08:00
rerere.h
reset.c
reset.h
resolve-undo.c
resolve-undo.h
revision.c Merge branch 'ab/lose-grep-debug' 2021-02-10 14:48:31 -08:00
revision.h Merge branch 'so/log-diff-merge' 2021-02-05 16:40:44 -08:00
run-command.c
run-command.h run-command: document use_shell option 2021-01-22 14:21:32 -08:00
send-pack.c Merge branch 'js/trace2-session-id' 2020-12-08 15:11:20 -08:00
send-pack.h
sequencer.c Merge branch 'ds/more-index-cleanups' 2021-02-10 14:48:33 -08:00
sequencer.h
serve.c
serve.h
server-info.c
setup.c
sh-i18n--envsubst.c
sha1dc_git.c
sha1dc_git.h
shallow.c commit_graft_pos(): take an oid instead of a bare hash 2021-01-28 11:21:07 -08:00
shallow.h
shell.c
shortlog.h shortlog: remove unused(?) "repo-abbrev" feature 2021-01-12 14:04:42 -08:00
sideband.c
sideband.h
sigchain.c
sigchain.h
split-index.c
split-index.h
stable-qsort.c
strbuf.c
strbuf.h
streaming.c
streaming.h
string-list.c
string-list.h
strmap.c
strmap.h strmap: make callers of strmap_remove() to call it in void context 2020-12-15 15:30:44 -08:00
strvec.c
strvec.h
sub-process.c
sub-process.h
submodule-config.c
submodule-config.h
submodule.c Merge branch 'sj/untracked-files-in-submodule-directory-is-not-dirty' 2021-01-25 14:19:18 -08:00
submodule.h
symlinks.c
tag.c
tag.h
tar.h
tempfile.c
tempfile.h
thread-utils.c
thread-utils.h
tmp-objdir.c
tmp-objdir.h
trace.c
trace.h
trace2.c
trace2.h
trailer.c pretty format %(trailers): add a "key_value_separator" 2020-12-09 14:16:42 -08:00
trailer.h pretty format %(trailers): add a "key_value_separator" 2020-12-09 14:16:42 -08:00
transport-helper.c
transport-internal.h
transport.c
transport.h
tree-diff.c
tree-walk.c tree-walk: report recursion counts 2021-01-04 15:23:08 -08:00
tree-walk.h
tree.c tree: enable cmp_cache_name_compare() to be used elsewhere 2020-12-13 14:18:20 -08:00
tree.h tree: enable cmp_cache_name_compare() to be used elsewhere 2020-12-13 14:18:20 -08:00
unicode-width.h
unimplemented.sh
unix-socket.c
unix-socket.h
unpack-trees.c sparse-checkout: load sparse-checkout patterns 2021-01-23 17:14:07 -08:00
unpack-trees.h
upload-pack.c refs: switch peel_ref() to peel_iterated_oid() 2021-01-21 15:51:31 -08:00
upload-pack.h
url.c
url.h
urlmatch.c
urlmatch.h
usage.c Merge branch 'jt/trace-error-on-warning' 2020-12-08 15:11:17 -08:00
userdiff.c
userdiff.h
utf8.c
utf8.h
varint.c
varint.h
version.c
version.h
versioncmp.c
walker.c
walker.h
wildmatch.c
wildmatch.h
worktree.c worktree: teach worktree_lock_reason() to gently handle main worktree 2021-01-30 09:57:20 -08:00
worktree.h worktree: teach worktree to lazy-load "prunable" reason 2021-01-30 09:57:16 -08:00
wrap-for-bin.sh
wrapper.c
write-or-die.c
ws.c
wt-status.c Merge branch 'sj/untracked-files-in-submodule-directory-is-not-dirty' 2021-01-25 14:19:18 -08:00
wt-status.h branch: sort detached HEAD based on a flag 2021-01-07 15:13:21 -08:00
xdiff-interface.c
xdiff-interface.h
zlib.c

README.md

Build status

Git - fast, scalable, distributed revision control system

Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.

Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.

Please read the file INSTALL for installation instructions.

Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.

See Documentation/gittutorial.txt to get started, then see Documentation/giteveryday.txt for a useful minimum set of commands, and Documentation/git-<commandname>.txt for documentation of each command. If git has been correctly installed, then the tutorial can also be read with man gittutorial or git help tutorial, and the documentation of each command with man git-<commandname> or git help <commandname>.

CVS users may also want to read Documentation/gitcvs-migration.txt (man gitcvs-migration or git help cvs-migration if git is installed).

The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission). To subscribe to the list, send an email with just "subscribe git" in the body to majordomo@vger.kernel.org. The mailing list archives are available at https://lore.kernel.org/git/, http://marc.info/?l=git and other archival sites.

Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.

The maintainer frequently sends the "What's cooking" reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.

The name "git" was given by Linus Torvalds when he wrote the very first version. He described the tool as "the stupid content tracker" and the name as (depending on your mood):

  • random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant.
  • stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
  • "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
  • "goddamn idiotic truckload of sh*t": when it breaks