Commit graph

60723 commits

Author SHA1 Message Date
Johannes Schindelin 7d78d5fc1a ci: skip GitHub workflow runs for already-tested commits/trees
When pushing a commit that has already passed a CI or PR build
successfully, it makes sense to save some energy and time and skip the
new build.

Let's teach our GitHub workflow to do that.

For good measure, we also compare the tree ID, which is what we actually
test (the commit ID might have changed due to a reworded commit message,
which should not affect the outcome of the run).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-08 11:58:37 -07:00
Junio C Hamano d98273ba77 Git 2.29-rc0
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-05 14:01:56 -07:00
Junio C Hamano 542b3c2573 Merge branch 'nl/credential-crlf'
Loosen the parser in the receiving end of the credential protocol
to allow credential helper to terminate lines with CRLF line
ending, as well as LF line ending.

* nl/credential-crlf:
  credential: treat CR/LF as line endings in the credential protocol
2020-10-05 14:01:56 -07:00
Junio C Hamano 67af910276 Merge branch 'sn/fast-import-doc'
Doc update.

* sn/fast-import-doc:
  fast-import: fix typo in documentation
2020-10-05 14:01:56 -07:00
Junio C Hamano 9d19e1773c Merge branch 'pb/submodule-doc-fix'
Doc update.

* pb/submodule-doc-fix:
  gitsubmodules doc: invoke 'ls-files' with '--recurse-submodules'
2020-10-05 14:01:55 -07:00
Junio C Hamano 5f8c70a148 Merge branch 'jk/format-auto-base-when-able'
"git format-patch" learns to take "whenAble" as a possible value
for the format.useAutoBase configuration variable to become no-op
when the  automatically computed base does not make sense.

* jk/format-auto-base-when-able:
  format-patch: teach format.useAutoBase "whenAble" option
2020-10-05 14:01:55 -07:00
Junio C Hamano 7da656f1e0 Merge branch 'jk/diff-cc-oidfind-fix'
"log -c --find-object=X" did not work well to find a merge that
involves a change to an object X from only one parent.

* jk/diff-cc-oidfind-fix:
  combine-diff: handle --find-object in multitree code path
2020-10-05 14:01:55 -07:00
Junio C Hamano 8e3ec76a20 Merge branch 'jk/refspecs-negative'
"git fetch" and "git push" support negative refspecs.

* jk/refspecs-negative:
  refspec: add support for negative refspecs
2020-10-05 14:01:54 -07:00
Junio C Hamano f6b06b4590 Merge branch 'rs/archive-add-file'
"git archive" learns the "--add-file" option to include untracked
files into a snapshot from a tree-ish.

* rs/archive-add-file:
  Makefile: use git-archive --add-file
  archive: add --add-file
  archive: read short blobs in archive.c::write_archive_entry()
2020-10-05 14:01:53 -07:00
Junio C Hamano e68f0a4e57 Merge branch 'jt/keep-partial-clone-filter-upon-lazy-fetch'
The lazy fetching done internally to make missing objects available
in a partial clone incorrectly made permanent damage to the partial
clone filter in the repository, which has been corrected.

* jt/keep-partial-clone-filter-upon-lazy-fetch:
  fetch: do not override partial clone filter
  promisor-remote: remove unused variable
2020-10-05 14:01:53 -07:00
Junio C Hamano 300cd14ee9 Merge branch 'td/submodule-update-quiet'
"git submodule update --quiet" did not squelch underlying "rebase"
and "pull" commands.

* td/submodule-update-quiet:
  submodule update: silence underlying merge/rebase with "--quiet"
2020-10-05 14:01:53 -07:00
Junio C Hamano 19dd352d03 Merge branch 'jk/unused'
Code cleanup.

* jk/unused:
  dir.c: drop unused "untracked" from treat_path_fast()
  sequencer: handle ignore_footer when parsing trailers
  test-advise: check argument count with argc instead of argv
  sparse-checkout: fill in some options boilerplate
  sequencer: drop repository argument from run_git_commit()
  push: drop unused repo argument to do_push()
  assert PARSE_OPT_NONEG in parse-options callbacks
  env--helper: write to opt->value in parseopt helper
  drop unused argc parameters
  convert: drop unused crlf_action from check_global_conv_flags_eol()
2020-10-05 14:01:52 -07:00
Junio C Hamano 8250ab0b8c Merge branch 'js/cmake-vs'
Using the CMake support we added some time ago for real with Visual
Studio build revealed there were lot of usability improvements
possible, which have been carried out.

* js/cmake-vs:
  hashmap_for_each_entry(): workaround MSVC's runtime check failure #3
  cmake (Windows): recommend using Visual Studio's built-in CMake support
  cmake (Windows): initialize vcpkg/build dependencies automatically
  cmake (Windows): complain when encountering an unknown compiler
  cmake (Windows): let the `.dll` files be found when running the tests
  cmake: quote the path accurately when editing `test-lib.sh`
  cmake: fall back to using `vcpkg`'s `msgfmt.exe` on Windows
  cmake: ensure that the `vcpkg` packages are found on Windows
  cmake: do find Git for Windows' shell interpreter
  cmake: ignore files generated by CMake as run in Visual Studio
2020-10-05 14:01:52 -07:00
Junio C Hamano 07601b5b36 Merge branch 'ma/worktree-cleanups'
Code clean-up.

* ma/worktree-cleanups:
  worktree: use skip_prefix to parse target
  worktree: rename copy-pasted variable
  worktree: update renamed variable in comment
  worktree: inline `worktree_ref()` into its only caller
  wt-status: introduce wt_status_state_free_buffers()
  wt-status: print to s->fp, not stdout
  wt-status: replace sha1 mentions with oid
2020-10-05 14:01:52 -07:00
Junio C Hamano 34415c76c8 Merge branch 'so/combine-diff-simplify'
Code simplification.

* so/combine-diff-simplify:
  diff: get rid of redundant 'dense' argument
2020-10-05 14:01:51 -07:00
Junio C Hamano 58138d3f26 Merge branch 'js/default-branch-name-part-2'
Update the tests to drop word 'master' from them.

* js/default-branch-name-part-2:
  t9902: avoid using the branch name `master`
  tests: avoid variations of the `master` branch name
  t3200: avoid variations of the `master` branch name
  fast-export: avoid using unnecessary language in a code comment
  t/test-terminal: avoid non-inclusive language
2020-10-05 14:01:50 -07:00
Junio C Hamano 0cf28f6d47 Merge branch 'pm/gitk-update'
"gitk" update.

* pm/gitk-update:
  gitk: Resize panes correctly when reducing window size
  gitk: replace tabs with spaces
  gitk: fix the context menu not appearing in the presence of submodule diffs
  gitk: Un-hide selection in areas with non-default background color
  gitk: add diff lines background colors
  gitk: be prepared to be run in a bare repository
  gitk: Preserve window dimensions on exit when not using ttk themes
  gitk: don't highlight files after submodules as submodules
  gitk: fix branch name encoding error
  gitk: rename "commit summary" to "commit reference"
2020-10-05 14:01:50 -07:00
Junio C Hamano c01b041ef0 Merge branch 'ds/in-merge-bases-many-optim-bug'
in_merge_bases_many(), a way to see if a commit is reachable from
any commit in a set of commits, was totally broken when the
commit-graph feature was in use, which has been corrected.

* ds/in-merge-bases-many-optim-bug:
  commit-reach: fix in_merge_bases_many bug
2020-10-05 14:01:50 -07:00
Samanta Navarro 3be01e5ab1 fast-import: fix typo in documentation
Signed-off-by: Samanta Navarro <ferivoz@riseup.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-04 12:56:29 -07:00
Philippe Blain 7d15fdbe4c gitsubmodules doc: invoke 'ls-files' with '--recurse-submodules'
`git ls-files` was never taught to respect the `submodule.recurse`
configuration variable, and it is too late now to change that [1],
but still the command is mentioned in 'gitsubmodules(7)' as if it
does respect that config.

Adjust the call in 'gitsubmodules(7)' by calling 'ls-files' with the
'--recurse-submodules' option.

While at it, uniformize the capitalization in that file, and use
backticks instead of quotes for Git commands and configuration
variables.

[1] https://lore.kernel.org/git/pull.732.git.1599707259907.gitgitgadget@gmail.com/T/#u

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-04 12:54:07 -07:00
Junio C Hamano ab4691b67b Nineteenth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-04 12:49:15 -07:00
Junio C Hamano 26b42b4dd8 Merge branch 'mt/delta-base-cache-races'
A race that leads to an access to a free'd data was corrected in
the codepath that reads pack files.

* mt/delta-base-cache-races:
  packfile: fix memory leak in add_delta_base_cache()
  packfile: fix race condition on unpack_entry()
2020-10-04 12:49:15 -07:00
Junio C Hamano 2fa8aacc72 Merge branch 'jk/shortlog-group-by-trailer'
"git shortlog" has been taught to group commits by the contents of
the trailer lines, like "Reviewed-by:", "Coauthored-by:", etc.

* jk/shortlog-group-by-trailer:
  shortlog: allow multiple groups to be specified
  shortlog: parse trailer idents
  shortlog: rename parse_stdin_ident()
  shortlog: de-duplicate trailer values
  shortlog: match commit trailers with --group
  trailer: add interface for iterating over commit trailers
  shortlog: add grouping option
  shortlog: change "author" variables to "ident"
2020-10-04 12:49:14 -07:00
Junio C Hamano ea1f6118b7 Merge branch 'jc/fmt-merge-msg-suppress-destination'
Docfix.

* jc/fmt-merge-msg-suppress-destination:
  config/fmt-merge-msg.txt: drop space in quote
2020-10-04 12:49:13 -07:00
Junio C Hamano d1b75045a0 Merge branch 'tb/upload-pack-filters'
Hotfix.

* tb/upload-pack-filters:
  config/uploadpack.txt: fix typo in `--filter=tree:<n>`
2020-10-04 12:49:12 -07:00
Junio C Hamano 84cdeed1cb Merge branch 'jc/sequencer-stopped-sha-simplify'
Code simplification.

* jc/sequencer-stopped-sha-simplify:
  sequencer: stop abbreviating stopped-sha file
2020-10-04 12:49:11 -07:00
Junio C Hamano 741f1f8131 Merge branch 'au/complete-restore-s'
The command line completion (in contrib/) learned that "git restore
-s <TAB>" is often followed by a refname.

* au/complete-restore-s:
  completion: complete refs after 'git restore -s'
  completion: use "prev" variable instead of introducing "prevword"
2020-10-04 12:49:09 -07:00
Junio C Hamano 03b0198e30 Merge branch 'al/ref-filter-merged-and-no-merged'
Hotfix.

* al/ref-filter-merged-and-no-merged:
  ref-filter: plug memory leak in reach_filter()
2020-10-04 12:49:09 -07:00
Junio C Hamano 9839cce4a7 Merge branch 'eg/mailinfo-doc-scissors'
The explanation of the "scissors line" has been clarified.

* eg/mailinfo-doc-scissors:
  Doc: show example scissors line
2020-10-04 12:49:09 -07:00
Junio C Hamano f4cc68cbd0 Merge branch 'mr/bisect-in-c-2'
Rewrite of the "git bisect" script in C continues.

* mr/bisect-in-c-2:
  bisect--helper: reimplement `bisect_next` and `bisect_auto_next` shell functions in C
  bisect: call 'clear_commit_marks_all()' in 'bisect_next_all()'
  bisect--helper: reimplement `bisect_autostart` shell function in C
  bisect--helper: introduce new `write_in_file()` function
  bisect--helper: use '-res' in 'cmd_bisect__helper' return
  bisect--helper: BUG() in cmd_*() on invalid subcommand
2020-10-04 12:49:08 -07:00
Junio C Hamano 03a01824a4 Merge branch 'cc/bisect-start-fix'
"git bisect start X Y", when X and Y are not valid committish
object names, should take X and Y as pathspec, but didn't.

* cc/bisect-start-fix:
  bisect: don't use invalid oid as rev when starting
2020-10-04 12:49:08 -07:00
Junio C Hamano 230ff3e997 Merge branch 'jc/blame-ignore-fix'
"git blame --ignore-rev/--ignore-revs-file" failed to validate
their input are valid revision, and failed to take into account
that the user may want to give an annotated tag instead of a
commit, which has been corrected.

* jc/blame-ignore-fix:
  blame: validate and peel the object names on the ignore list
  t8013: minimum preparatory clean-up
2020-10-04 12:49:07 -07:00
Junio C Hamano 86cca370e1 Merge branch 'jk/drop-unaligned-loads'
Compilation fix around type punning.

* jk/drop-unaligned-loads:
  Revert "fast-export: use local array to store anonymized oid"
  bswap.h: drop unaligned loads
2020-10-04 12:49:06 -07:00
Junio C Hamano 94de88c986 Merge branch 'js/no-builtins-on-disk-option'
The installation procedure learned to optionally omit "git-foo"
executable files for each 'foo' built-in subcommand, which are only
required by old timers that still rely on the age old promise that
prepending "git --exec-path" output to PATH early in their script
will keep the "git-foo" calls they wrote working.

The old attempt to remove these executables from the disk failed in
the 1.6 era; it may be worth attempting again, but I think it is
worth to keep this topic separate from such a policy change to help
it graduate early.

* js/no-builtins-on-disk-option:
  ci: stop linking built-ins to the dashed versions
  Optionally skip linking/copying the built-ins
  msvc: copy the correct `.pdb` files in the Makefile target `install`
2020-10-04 12:49:05 -07:00
Junio C Hamano 5a25615d5c Merge branch 'ab/mediawiki-fixes'
Modernization and fixes to MediaWiki remote backend.

* ab/mediawiki-fixes:
  remote-mediawiki: use "sh" to eliminate unquoted commands
  remote-mediawiki: annotate unquoted uses of run_git()
  remote-mediawiki: convert to quoted run_git() invocation
  remote-mediawiki: provide a list form of run_git()
  remote-mediawiki tests: annotate failing tests
  remote-mediawiki: fix duplicate revisions being imported
  remote-mediawiki tests: use CLI installer
  remote-mediawiki tests: use inline PerlIO for readability
  remote-mediawiki tests: replace deprecated Perl construct
  remote-mediawiki tests: use a more idiomatic dispatch table
  remote-mediawiki tests: use "$dir/" instead of "$dir."
  remote-mediawiki tests: change `[]` to `test`
  remote-mediawiki tests: use test_cmp in tests
  remote-mediawiki tests: use a 10 character password
  remote-mediawiki tests: use the login/password variables
  remote-mediawiki doc: don't hardcode Debian PHP versions
  remote-mediawiki doc: link to MediaWiki's current version
  remote-mediawiki doc: correct link to GitHub project
2020-10-04 12:49:04 -07:00
Nikita Leonov 356c473295 credential: treat CR/LF as line endings in the credential protocol
This fix makes using Git credentials more friendly to Windows users: it
allows a credential helper to communicate using CR/LF line endings ("DOS
line endings" commonly found on Windows) instead of LF-only line endings
("Unix line endings").

Note that this changes the behavior a bit: if a credential helper
produces, say, a password with a trailing Carriage Return character,
that will now be culled even when the rest of the lines end only in Line
Feed characters, indicating that the Carriage Return was not meant to be
part of the line ending.

In practice, it seems _very_ unlikely that something like this happens.
Passwords usually need to consist of non-control characters, URLs need
to have special characters URL-encoded, and user names, well, are names.

However, it _does_ help on Windows, where CR/LF line endings are common:
as unrecognized commands are simply ignored by the credential machinery,
even a command like `quit\r` (which is clearly intended to abort) would
simply be ignored (silently) by Git.

So let's change the credential machinery to accept both CR/LF and LF
line endings.

While we do this for the credential helper protocol, we do _not_ adjust
`git credential-cache--daemon` (which won't work on Windows, anyway,
because it requires Unix sockets) nor `git credential-store` (which
writes the file `~/.git-credentials` which we consider an implementation
detail that should be opaque to the user, read: we do expect users _not_
to edit this file manually).

Signed-off-by: Nikita Leonov <nykyta.leonov@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-03 10:41:03 -07:00
Junio C Hamano e2b9cb1c5a Merge remote-tracking branch 'paulus/master' into pm/gitk-update
* paulus/master:
  gitk: Resize panes correctly when reducing window size
  gitk: replace tabs with spaces
  gitk: fix the context menu not appearing in the presence of submodule diffs
  gitk: Un-hide selection in areas with non-default background color
  gitk: add diff lines background colors
  gitk: be prepared to be run in a bare repository
  gitk: Preserve window dimensions on exit when not using ttk themes
  gitk: don't highlight files after submodules as submodules
  gitk: fix branch name encoding error
  gitk: rename "commit summary" to "commit reference"
2020-10-03 10:06:27 -07:00
Paul Mackerras 6cd80496e9 gitk: Resize panes correctly when reducing window size
The resizeclistpanes and resizecdetpanes procedures attempt to keep
the horizontal proportions of the panes of the gitk window
approximately constant when the gitk window is resized.  However, if
the size is reduced enough that an existing sash position would go
outside the window, Tk moves the sash to the left to keep it inside
the window (without moving other sash positions to keep the
proportions).  This happens before these resize procedures get
control, and so they work with incorrect proportions.

To fix this, we record the sash positions we set previously and use
those previously-set sash positions rather than the current sash
positions when computing the proportions.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2020-10-03 15:20:33 +10:00
Denton Liu e244588eb6 gitk: replace tabs with spaces
The source code is a mix of tabs and spaces. The indentation style
currently is four spaces per indent level but uses tabs every other
level (at eight spaces). Fix this inconsistent spacing and tabbing by
just using a space-indent for everything.

This was done mechanically by running:

	$ expand -i gitk >gitk.new
	$ mv gitk.new gitk

This patch should be empty with `--ignore-all-space`.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2020-10-03 14:55:38 +10:00
Derrick Stolee 8791bf1841 commit-reach: fix in_merge_bases_many bug
Way back in f9b8908b (commit.c: use generation numbers for
in_merge_bases(), 2018-05-01), a heuristic was used to short-circuit
the in_merge_bases() walk. This works just fine as long as the
caller is checking only two commits, but when there are multiple,
there is a possibility that this heuristic is _very wrong_.

Some code moves since then has changed this method to
repo_in_merge_bases_many() inside commit-reach.c. The heuristic
computes the minimum generation number of the "reference" list, then
compares this number to the generation number of the "commit".

In a recent topic, a test was added that used in_merge_bases_many()
to test if a commit was reachable from a number of commits pulled
from a reflog. However, this highlighted the problem: if any of the
reference commits have a smaller generation number than the given
commit, then the walk is skipped _even if there exist some with
higher generation number_.

This heuristic is wrong! It must check the MAXIMUM generation number
of the reference commits, not the MINIMUM.

This highlights a testing gap. t6600-test-reach.sh covers many
methods in commit-reach.c, including in_merge_bases() and
get_merge_bases_many(), but since these methods either restrict to
two input commits or actually look for the full list of merge bases,
they don't check this heuristic!

Add a possible input to "test-tool reach" that tests
in_merge_bases_many() and add tests to t6600-test-reach.sh that
cover this heuristic. This includes cases for the reference commits
having generation above and below the generation of the input commit,
but also having maximum generation below the generation of the input
commit.

The fix itself is to swap min_generation with a max_generation in
repo_in_merge_bases_many().

Reported-by: Srinidhi Kaushik <shrinidhi.kaushik@gmail.com>
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-02 10:26:31 -07:00
Jacob Keller 7efba5fa39 format-patch: teach format.useAutoBase "whenAble" option
The format.useAutoBase configuration option exists to allow users to
enable '--base=auto' for format-patch by default.

This can sometimes lead to poor workflow, due to unexpected failures
when attempting to format an ancient patch:

    $ git format-patch -1 <an old commit>
    fatal: base commit shouldn't be in revision list

This can be very confusing, as it is not necessarily immediately obvious
that the user requested a --base (since this was in the configuration,
not on the command line).

We do want --base=auto to fail when it cannot provide a suitable base,
as it would be equally confusing if a formatted patch did not include
the base information when it was requested.

Teach format.useAutoBase a new mode, "whenAble". This mode will cause
format-patch to attempt to include a base commit when it can. However,
if no valid base commit can be found, then format-patch will continue
formatting the patch without a base commit.

In order to avoid making yet another branch name unusable with --base,
do not teach --base=whenAble or --base=whenable.

Instead, refactor the base_commit option to use a callback, and rely on
the global configuration variable auto_base.

This does mean that a user cannot request this optional base commit
generation from the command line. However, this is likely not too
valuable. If the user requests base information manually, they will be
immediately informed of the failure to acquire a suitable base commit.
This allows the user to make an informed choice about whether to
continue the format.

Add tests to cover the new mode of operation for --base.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-01 15:22:10 -07:00
Theodore Dubois 3ad0401e9e submodule update: silence underlying merge/rebase with "--quiet"
Commands such as

    $ git pull --rebase --recurse-submodules --quiet

produce non-quiet output from the merge or rebase.  Pass the --quiet
option down when invoking "rebase" and "merge".

Also fix the parsing of git submodule update -v.

When e84c3cf3 (git-submodule.sh: accept verbose flag in cmd_update
to be non-quiet, 2018-08-14) taught "git submodule update" to take
"--quiet", it apparently did not know how ${GIT_QUIET:+--quiet}
works, and reviewers seem to have missed that setting the variable
to "0", rather than unsetting it, still results in "--quiet" being
passed to underlying commands.

Signed-off-by: Theodore Dubois <tbodt@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-01 08:50:24 -07:00
Jacob Keller c0192df630 refspec: add support for negative refspecs
Both fetch and push support pattern refspecs which allow fetching or
pushing references that match a specific pattern. Because these patterns
are globs, they have somewhat limited ability to express more complex
situations.

For example, suppose you wish to fetch all branches from a remote except
for a specific one. To allow this, you must setup a set of refspecs
which match only the branches you want. Because refspecs are either
explicit name matches, or simple globs, many patterns cannot be
expressed.

Add support for a new type of refspec, referred to as "negative"
refspecs. These are prefixed with a '^' and mean "exclude any ref
matching this refspec". They can only have one "side" which always
refers to the source. During a fetch, this refers to the name of the ref
on the remote. During a push, this refers to the name of the ref on the
local side.

With negative refspecs, users can express more complex patterns. For
example:

 git fetch origin refs/heads/*:refs/remotes/origin/* ^refs/heads/dontwant

will fetch all branches on origin into remotes/origin, but will exclude
fetching the branch named dontwant.

Refspecs today are commutative, meaning that order doesn't expressly
matter. Rather than forcing an implied order, negative refspecs will
always be applied last. That is, in order to match, a ref must match at
least one positive refspec, and match none of the negative refspecs.
This is similar to how negative pathspecs work.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-30 14:52:00 -07:00
Jeff King 957876f17d combine-diff: handle --find-object in multitree code path
When doing combined diffs, we have two possible code paths:

  - a slower one which independently diffs against each parent, applies
    any filters, and then intersects the resulting paths

  - a faster one which walks all trees simultaneously

When the diff options specify that we must do certain filters, like
pickaxe, then we always use the slow path, since the pickaxe code only
knows how to handle filepairs, not the n-parent entries generated for
combined diffs.

But there are two problems with the slow path:

 1. It's slow. Running:

      git rev-list HEAD | git diff-tree --stdin -r -c

    in git.git takes ~3s on my machine. But adding "--find-object" to
    that increases it to ~6s, even though find-object itself should
    incur only a few extra oid comparisons. On linux.git, it's even
    worse: 35s versus 215s.

 2. It doesn't catch all cases where a particular path is interesting.
    Consider a merge with parent blobs X and Y for a particular path,
    and end result Z. That should be interesting according to "-c",
    because the result doesn't match either parent. And it should be
    interesting even with "--find-object=X", because "X" went away in
    the merge.

    But because we perform each pairwise diff independently, this
    confuses the intersection code. The change from X to Z is still
    interesting according to --find-object. But in the other parent we
    went from Y to Z, so the diff appears empty! That causes the
    intersection code to think that parent didn't change the path, and
    thus it's not interesting for "-c".

This patch fixes both by implementing --find-object for the multitree
code. It's a bit unfortunate that we have to duplicate some logic from
diffcore-pickaxe, but this is the best we can do for now. In an ideal
world, all of the diffcore code would stop thinking about filepairs and
start thinking about n-parent sets, and we could use the multitree walk
with all of it.

Until then, there are some leftover warts:

  - other pickaxe operations, like -S or -G, still suffer from both
    problems. These would be hard to adapt because they rely on having
    a diff_filespec() for each path to look at content. And we'd need to
    define what an n-way "change" means in each case (probably easy for
    "-S", which can compare counts, but not so clear for -G, which is
    about grepping diffs).

  - other options besides --find-object may cause us to use the slow
    pairwise path, in which case we'll go back to producing a different
    (wrong) answer for the X/Y/Z case above.

We may be able to hack around these, but I think the ultimate solution
will be a larger rewrite of the diffcore code. For now, this patch
improves one specific case but leaves the rest.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-30 13:35:24 -07:00
Junio C Hamano 0ad621f61e hashmap_for_each_entry(): workaround MSVC's runtime check failure #3
The OFFSETOF_VAR(var, member) macro is implemented in terms of
offsetof(typeof(*var), member) with compilers that know typeof(),
but its fallback implemenation compares &(var->member) and (var) and
count the distance in bytes, i.e.

    ((uintptr_t)&(var)->member - (uintptr_t)(var))

MSVC's runtime check, when fed an uninitialized 'var', flags this as
a use of an uninitialized variable (and that is legit---uninitialized
contents of 'var' is subtracted) in a debug build.

After auditing all 6 uses of OFFSETOF_VAR(), 1 of them does feed a
potentially uninitialized 'var' to the macro in the beginning of the
for() loop:

    #define hashmap_for_each_entry(map, iter, var, member) \
            for (var = hashmap_iter_first_entry_offset(map, iter, \
                                                    OFFSETOF_VAR(var, member)); \
                    var; \
                    var = hashmap_iter_next_entry_offset(iter, \
                                                    OFFSETOF_VAR(var, member)))

We can work around this by making sure that var has _some_ value
when OFFSETOF_VAR() is called.  Strictly speaking, it invites
undefined behaviour to use NULL here if we end up with pointer
comparison, but MSVC runtime seems to be happy with it, and most
other systems have typeof() and don't even need pointer comparison
fallback code.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-30 13:26:54 -07:00
Johannes Schindelin f2f1250c47 cmake (Windows): recommend using Visual Studio's built-in CMake support
It is a lot more convenient to use than having to specify the
configuration in CMake manually (does not matter whether using the
command-line or CMake's GUI).

While at it, recommend using `contrib/buildsystems/out/` as build
directory also in the part that talks about running CMake manually.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-30 13:26:54 -07:00
Johannes Schindelin b490283d52 cmake (Windows): initialize vcpkg/build dependencies automatically
The idea of having CMake support in Git's source tree is to enable
contributors on Windows to start contributing with little effort. To
that end, we just added some sensible defaults that will let users open
the worktree in Visual Studio and start building.

This expects the dependencies (such as zlib) to be available already,
though. If they are not available, we expect the user to run
`compat/vcbuild/vcpkg_install.bat`.

Rather than requiring this step to be manual, detect the situation and
run it as part of the CMake configuration step.

Note that this obviously only applies to the scenario when we want to
compile in Visual Studio (i.e. with MS Visual C), not with GCC.
Therefore, we guard this new code block behind the `MSVC` conditional.

This concludes our journey to make it as effortless as possible to start
developing Git in Visual Studio: all the developer needs to do is to
clone Git's repository, open the worktree via `File>Open>Folder...` and
wait for CMake to finish configuring.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-30 13:26:36 -07:00
Johannes Schindelin 2d9eb4ed2c cmake (Windows): complain when encountering an unknown compiler
We have some custom handling regarding the link options, which are
specific to each compiler.

Therefore: let's not just continue without setting the link options if
configuring for a currently unhandled compiler, but error out.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-30 13:25:59 -07:00
Johannes Schindelin 8c35e82898 cmake (Windows): let the .dll files be found when running the tests
Contrary to Unix-ish platforms, the dependencies' shared libraries are
not usually found in one central place. In our case, since we use
`vcpkg`, they are to be found inside the `compat/vcbuild/vcpkg/` tree.

Let's make sure that they are in the search path when running the tests.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-30 13:25:59 -07:00
Johannes Schindelin f1bd737957 cmake: quote the path accurately when editing test-lib.sh
By default, the build directory will be called something like
`contrib/buildsystems/out/build/x64-Debug (default)` (note the space and
the parentheses). We need to make sure that such a path is quoted
properly when editing the assignment of the `GIT_BUILD_DIR` variable.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-30 13:25:59 -07:00