Commit Graph

58187 Commits

Author SHA1 Message Date
Junio C Hamano
7137d6089b Merge branch 'ms/doc-bundle-format' into maint
Technical details of the bundle format has been documented.
I think this is in a good enough shape.

* ms/doc-bundle-format:
  doc: describe Git bundle format
2020-02-14 12:42:32 -08:00
Junio C Hamano
52d620fdc6 Merge branch 'es/submodule-fetch-message-fix' into maint
Error message fix.

* es/submodule-fetch-message-fix:
  submodule: add newline on invalid submodule error
2020-02-14 12:42:32 -08:00
Junio C Hamano
0ecc7d62f4 Merge branch 'jb/parse-options-message-fix' into maint
Error message fix.

* jb/parse-options-message-fix:
  parse-options: lose an unnecessary space in an error message
2020-02-14 12:42:32 -08:00
Junio C Hamano
1ea6edfd55 Merge branch 'ma/filter-branch-doc-caret' into maint
Doc mark-up updates.

* ma/filter-branch-doc-caret:
  git-filter-branch.txt: wrap "maths" notation in backticks
2020-02-14 12:42:32 -08:00
Junio C Hamano
cfa25e197d Merge branch 'km/submodule-doc-use-sm-path' into maint
Docfix.

* km/submodule-doc-use-sm-path:
  submodule foreach: replace $path with $sm_path in example
2020-02-14 12:42:32 -08:00
Junio C Hamano
153a1b46f1 Merge branch 'pb/do-not-recurse-grep-no-index' into maint
"git grep --no-index" should not get affected by the contents of
the .gitmodules file but when "--recurse-submodules" is given or
the "submodule.recurse" variable is set, it did.  Now these
settings are ignored in the "--no-index" mode.

* pb/do-not-recurse-grep-no-index:
  grep: ignore --recurse-submodules if --no-index is given
2020-02-14 12:42:31 -08:00
Junio C Hamano
8857657cc9 Merge branch 'jt/t5616-robustify' into maint
Futureproofing a test not to depend on the current implementation
detail.

* jt/t5616-robustify:
  t5616: make robust to delta base change
2020-02-14 12:42:31 -08:00
Junio C Hamano
1f7609b520 Merge branch 'en/fill-directory-fixes-more' into maint
Corner case bugs in "git clean" that stems from a (necessarily for
performance reasons) awkward calling convention in the directory
enumeration API has been corrected.

* en/fill-directory-fixes-more:
  dir: point treat_leading_path() warning to the right place
  dir: restructure in a way to avoid passing around a struct dirent
  dir: treat_leading_path() and read_directory_recursive(), round 2
  clean: demonstrate a bug with pathspecs
2020-02-14 12:42:31 -08:00
Junio C Hamano
f468972671 Merge branch 'bc/misconception-doc' into maint
Doc updates.

* bc/misconception-doc:
  docs: mention when increasing http.postBuffer is valuable
  doc: dissuade users from trying to ignore tracked files
2020-02-14 12:42:31 -08:00
Junio C Hamano
6e69042e26 Merge branch 'bc/author-committer-doc' into maint
Clarify documentation on committer/author identities.

* bc/author-committer-doc:
  doc: provide guidance on user.name format
  docs: expand on possible and recommended user config options
  doc: move author and committer information to git-commit(1)
2020-02-14 12:42:31 -08:00
Junio C Hamano
650ed395be Merge branch 'ds/refmap-doc' into maint
"git fetch --refmap=" option has got a better documentation.

* ds/refmap-doc:
  fetch: document and test --refmap=""
2020-02-14 12:42:30 -08:00
Junio C Hamano
80b806f1a8 Merge branch 'bc/actualmente' into maint
Doc grammo fix.

* bc/actualmente:
  docs: use "currently" for the present time
2020-02-14 12:42:30 -08:00
Junio C Hamano
eceff4ba12 Merge branch 'rt/submodule-i18n' into maint
Comments update.

* rt/submodule-i18n:
  submodule.c: mark more strings for translation
2020-02-14 12:42:30 -08:00
Junio C Hamano
8a17eb7972 Merge branch 'jk/test-fixes' into maint
Test fixes.

* jk/test-fixes:
  t7800: don't rely on reuse_worktree_file()
  t4018: drop "debugging" cat from hunk-header tests
2020-02-14 12:42:30 -08:00
Junio C Hamano
54bbadaeca Merge branch 'jk/asan-build-fix' into maint
Work around test breakages caused by custom regex engine used in
libasan, when address sanitizer is used with more recent versions
of gcc and clang.

* jk/asan-build-fix:
  Makefile: use compat regex with SANITIZE=address
2020-02-14 12:42:29 -08:00
Junio C Hamano
8dbeba198e Merge branch 'ds/sparse-cone' into maint
The code recently added in this release to move to the entry beyond
the ones in the same directory in the index in the sparse-cone mode
did not count the number of entries to skip over incorrectly, which
has been corrected.

* ds/sparse-cone:
  .mailmap: fix GGG authoship screwup
  unpack-trees: correctly compute result count
2020-02-14 12:42:29 -08:00
Junio C Hamano
e361f36f61 Merge branch 'nd/switch-and-restore' into maint
"git restore --staged" did not correctly update the cache-tree
structure, resulting in bogus trees to be written afterwards, which
has been corrected.

* nd/switch-and-restore:
  restore: invalidate cache-tree when removing entries with --staged
2020-02-14 12:42:29 -08:00
Junio C Hamano
4a60c63a75 Merge branch 'jk/no-flush-upon-disconnecting-slrpc-transport' into maint
Reduce unnecessary round-trip when running "ls-remote" over the
stateless RPC mechanism.

* jk/no-flush-upon-disconnecting-slrpc-transport:
  transport: don't flush when disconnecting stateless-rpc helper
2020-02-14 12:42:28 -08:00
Junio C Hamano
ad9c895463 Merge branch 'hw/tutorial-favor-switch-over-checkout' into maint
Complete an update to tutorial that encourages "git switch" over
"git checkout" that was done only half-way.

* hw/tutorial-favor-switch-over-checkout:
  doc/gitcore-tutorial: fix prose to match example command
2020-02-14 12:42:28 -08:00
Junio C Hamano
5ae057d9a8 Merge branch 'es/unpack-trees-oob-fix' into maint
The code that tries to skip over the entries for the paths in a
single directory using the cache-tree was not careful enough
against corrupt index file.

* es/unpack-trees-oob-fix:
  unpack-trees: watch for out-of-range index position
2020-02-14 12:42:28 -08:00
Junio C Hamano
c17cf77e4e Merge branch 'bc/run-command-nullness-after-free-fix' into maint
C pedantry ;-) fix.

* bc/run-command-nullness-after-free-fix:
  run-command: avoid undefined behavior in exists_in_PATH
2020-02-14 12:42:27 -08:00
Junio C Hamano
d0ebd645b1 Merge branch 'en/string-list-can-be-custom-sorted' into maint
API-doc update.

* en/string-list-can-be-custom-sorted:
  string-list: note in docs that callers can specify sorting function
2020-02-14 12:42:27 -08:00
Junio C Hamano
9eddeaece1 Merge branch 'jt/sha1-file-remove-oi-skip-cached' into maint
has_object_file() said "no" given an object registered to the
system via pretend_object_file(), making it inconsistent with
read_object_file(), causing lazy fetch to attempt fetching an
empty tree from promisor remotes.

* jt/sha1-file-remove-oi-skip-cached:
  sha1-file: remove OBJECT_INFO_SKIP_CACHED
2020-02-14 12:42:27 -08:00
Junio C Hamano
3bba763373 Merge branch 'hw/commit-advise-while-rejecting' into maint
"git commit" gives output similar to "git status" when there is
nothing to commit, but without honoring the advise.statusHints
configuration variable, which has been corrected.

* hw/commit-advise-while-rejecting:
  commit: honor advice.statusHints when rejecting an empty commit
2020-02-14 12:42:27 -08:00
Johannes Schindelin
08809c09aa mingw: add a helper function to attach GDB to the current process
When debugging Git, the criss-cross spawning of processes can make
things quite a bit difficult, especially when a Unix shell script is
thrown in the mix that calls a `git.exe` that then segfaults.

To help debugging such things, we introduce the `open_in_gdb()` function
which can be called at a code location where the segfault happens (or as
close as one can get); This will open a new MinTTY window with a GDB
that already attached to the current process.

Inspired by Derrick Stolee.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-14 10:02:07 -08:00
Johannes Schindelin
bfe2bbb47f t5580: test cloning without file://, test fetching via UNC paths
On Windows, it is quite common to work with network drives. The format
of the paths to network drives (or "network shares", or UNC paths) is:

	\\<server>\<share>\...

We already have a couple regression tests revolving around those types
of paths, but we missed cloning and fetching from UNC paths without
leading `file://` (and with backslashes instead of forward slashes).
This lil' patch closes that gap.

It gets a bit silly to add the commands to the name of the test script,
so let's just rename it while we're testing more UNC stuff.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-14 09:59:41 -08:00
Johannes Schindelin
076ee3e8a2 tests: fix --write-junit-xml with subshells
In t0000, more precisely in its `test_bool_env` test case, there are two
subshells that are supposed to fail. To be even _more_ precise, they
fail by calling the `error` function, and that is okay, because it is in
a subshell, and it is expected that those two subshell invocations fail.

However, the `error` function also tries to finalize the JUnit XML (if
that XML was asked for, via `--write-junit-xml`. As a consequence, the
XML is edited to add a `time` attribute for the `testsuite` tag. And
since there are two expected `error` calls in addition to the final
`test_done`, the `finalize_junit_xml` function is called three times and
naturally the `time` attribute is added _three times_.

Azure Pipelines is not happy with that, complaining thusly:

 ##[warning]Failed to read D:\a\1\s\t\out\TEST-t0000-basic.xml. Error : 'time' is a duplicate attribute name. Line 2, position 82..

One possible way to address this would be to unset `write_junit_xml` in
the `test_bool_env` test case.

But that would be fragile, as other `error` calls in subshells could be
introduced.

So let's just modify `finalize_junit_xml` to remove any `time` attribute
before adding the authoritative one.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-12 09:19:42 -08:00
Johannes Schindelin
2b0f19fa7a convert: fix typo
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-11 12:03:09 -08:00
Johannes Schindelin
30183894ea ci: ignore rubygems warning in the "Documentation" job
A recent update in the Linux VM images used by Azure Pipelines surfaced
a new problem in the "Documentation" job. Apparently, this warning
appears 396 times on `stderr` when running `make doc`:

/usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb:10: warning: constant Gem::ConfigMap is deprecated

This problem was already reported to the `rubygems` project via
https://github.com/rubygems/rubygems/issues/3068.

As there is nothing Git can do about this warning, and as the
"Documentation" job reports this warning as a failure, let's just
silence it and move on.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-10 09:52:27 -08:00
Johannes Berg
eb31044ff7 pack-format: correct multi-pack-index description
The description of the multi-pack-index contains a small bug,
if all offsets are < 2^32 then there will be no LOFF chunk,
not only if they're all < 2^31 (since the highest bit is only
needed as the "LOFF-escape" when that's actually needed.)

Correct this, and clarify that in that case only offsets up
to 2^31-1 can be stored in the OOFF chunk.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-10 09:01:48 -08:00
Martin Ågren
9299f84921 diff-options.txt: avoid "regex" overload in example
When we exemplify the difference between `-G` and `-S` (using
`--pickaxe-regex`), we do so using an example diff and git-diff
invocation involving "regexec", "regexp", "regmatch", ...

The example is correct, but we can make it easier to untangle by
avoiding writing "regex.*" unless it's really needed to make our point.

Use some made-up, non-regexy words instead.

Reported-by: Adam Dinwoodie <adam@dinwoodie.org>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-09 09:25:24 -08:00
Masaya Suzuki
7378ec90e1 doc: describe Git bundle format
The bundle format was not documented. Describe the format with ABNF and
explain the meaning of each part.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 12:47:02 -08:00
Emily Shaffer
303b3c1c46 submodule: add newline on invalid submodule error
Since 'err' contains output for multiple submodules and is printed all
at once by fetch_populated_submodules(), errors for each submodule
should be newline separated for readability. The same strbuf is added to
with a newline in the other half of the conditional where this error is
detected, so make the two consistent.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-07 11:05:45 -08:00
Jacques Bodin-Hullin
395518cf7a parse-options: lose an unnecessary space in an error message
Signed-off-by: Jacques Bodin-Hullin <j.bodinhullin@monsieurbiz.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-05 10:49:29 -08:00
Jeff King
a21781011f index-pack: downgrade twice-resolved REF_DELTA to die()
When we're resolving a REF_DELTA, we compare-and-swap its type from
REF_DELTA to whatever real type the base object has, as discussed in
ab791dd138 (index-pack: fix race condition with duplicate bases,
2014-08-29). If the old type wasn't a REF_DELTA, we consider that a
BUG(). But as discussed in that commit, we might see this case whenever
we try to resolve an object twice, which may happen because we have
multiple copies of the base object.

So this isn't a bug at all, but rather a sign that the input pack is
broken. And indeed, this case is triggered already in t5309.5 and
t5309.6, which create packs with delta cycles and duplicate bases. But
we never noticed because those tests are marked expect_failure.

Those tests were added by b2ef3d9ebb (test index-pack on packs with
recoverable delta cycles, 2013-08-23), which was leaving the door open
for cases that we theoretically _could_ handle. And when we see an
already-resolved object like this, in theory we could keep going after
confirming that the previously resolved child->real_type matches
base->obj->real_type. But:

  - enforcing the "only resolve once" rule here saves us from an
    infinite loop in other parts of the code. If we keep going, then the
    delta cycle in t5309.5 causes us to loop infinitely, as
    find_ref_delta_children() doesn't realize which objects have already
    been resolved. So there would be more changes needed to make this
    case work, and in the meantime we'd be worse off.

  - any pack that triggers this is broken anyway. It either has a
    duplicate base object, or it has a cycle which causes us to bring in
    a duplicate via --fix-thin. In either case, we'd end up rejecting
    the pack in write_idx_file(), which also detects duplicates.

So the tests have little value in documenting what we _could_ be doing
(and have been neglected for 6+ years). Let's switch them to confirming
that we handle this case cleanly (and switch out the BUG() for a more
informative die() so that we do so).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-04 13:19:11 -08:00
Johan Herland
dbc27477ff notes.c: fix off-by-one error when decreasing notes fanout
As noted in the previous commit, the nature of the fanout heuristic
in the notes code causes the exact point at which we increase or
decrease the notes fanout to vary with the objects being annotated.
Since the object ids generated by the test environment are
deterministic (by design), the notes generated and tested by t3305
are always the same, and we therefore happen to see the same fanout
behavior from one run to the next.

Coincidentally, if we were to change the test environment slightly
(say by making a test commit on an unrelated branch before we start
the t3305 test proper), we not only see the fanout switch happen at
different points, we also manage to trigger a _bug_ in the notes
code where the fanout 1 -> 0 switch is not applied uniformly across
the notes tree, but instead yields a notes tree like this:

  ...
  bdeafb301e44b0e4db0f738a2d2a7beefdb70b70
  bff2d39b4f7122bd4c5caee3de353a774d1e632a
  d3/8ec8f851adf470131178085bfbaab4b12ad2a7
  e0b173960431a3e692ae929736df3c9b73a11d5b
  eb3c3aede523d729990ac25c62a93eb47c21e2e3
  ...

The bug occurs when we are writing out a notes tree with a newly
decreased fanout, and the notes tree contains unexpanded subtrees
that should be consolidated into the parent tree as a consequence of
the decreased fanout):

Subtrees that happen to sit at an _even_ level in the internal notes
16-tree structure (in other words: subtrees whose path - "d3" in the
example above - is unique in the first nibble - i.e. there are no
other note paths that start with "d") are _not_ unpacked as part of
the tree writeout. This error will repeat itself in subsequent note
trees until the subtree is forced to be unpacked. In t3305 this only
happens when the d38ec8f8 note is itself removed from the tree.

The error is not severe (no information is lost, and the notes code
is able to read/decode this tree and manipulate it correctly), but
this is nonetheless a bug in the current implementation that should
be fixed.

That said, fixing the off-by-one error is not without complications:
We must take into account that the load_subtree() call from
for_each_note_helper() (that is now done to correctly unpack the
subtree while we're writing out the notes tree) may end up inserting
unpacked non-notes into the linked list of non_note entries held by
the struct notes_tree. Since we are in the process of writing out the
notes tree, this linked list is currently in the process of being
traversed by write_each_non_note_until(). The unpacked non-notes are
necessarily inserted between the last non-note we wrote out, and the
next non-note to be written. Hence, we cannot simply hold the
next_non_note to write in struct write_each_note_data (as we would
then silently skip these newly inserted notes), but must instead
always follow the ->next pointer from the last non-note we wrote.
(This part was caught by an existing test in t3304.)

Cc: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Cc: Brian M. Carlson <sandals@crustytoothpaste.net>
Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-04 12:20:43 -08:00
Johan Herland
e1c5253951 t3305: check notes fanout more carefully and robustly
In short, before this patch, this test script:
 - creates many notes
 - verifies that all notes in the notes tree has a fanout of 1
 - removes most notes
 - verifies that the notes in the notes tree now has a fanout of 0

The fanout verification only happened twice: after creating all the
notes, and after removing most of them.

This patch strengthens the test by checking the fanout after _each_
added/removed note: We assert that the switch from fanout 0 -> 1
happens exactly once while adding notes (and that the switch pervades
the entire notes tree). Likewise, we assert that the switch from
fanout 1 -> 0 happens exactly once while removing notes.

Additionally, we decrease the number of notes left after removal,
from 50 to 15 notes, in order to ensure that fanout 1 -> 0 transition
keeps happening regardless of external factors[1].

[1]: Currently (with the SHA1 hash function and the deterministic
object ids of the test environment) the fanout heuristic in the notes
code happens to switch from 0 -> 1 at 109 notes, and from 1 -> 0 at
59 notes. However, changing the hash function or other external
factors will vary these numbers, and the latter may - in theory - go
as low as 15. For more details, please see the discussion at
https://public-inbox.org/git/20200125230035.136348-4-sandals@crustytoothpaste.net/

Cc: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Cc: Brian M. Carlson <sandals@crustytoothpaste.net>
Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-04 12:20:27 -08:00
Martin Ågren
e469afe158 git-filter-branch.txt: wrap "maths" notation in backticks
In this paragraph, we have a few instances of the '^' character, which
we give as "\^". This renders well with AsciiDoc ("^"), but Asciidoctor
renders it literally as "\^". Dropping the backslashes renders fine
with Asciidoctor, but not AsciiDoc...

An earlier version of this patch used "{caret}" instead of "^", which
avoided these escaping problems. The rendering was still so-so, though
-- these expressions end up set as normal text, similarly to when one
provides, e.g., computer code in the middle of running text, without
properly marking it with `backticks` to be monospaced.

As noted by Jeff King, this suggests actually wrapping these
expressions in backticks, setting them in monospace.

The lone "5" could be left as is or wrapped as `5`. Spell it out as
"five" instead -- this generally looks better anyway for small numbers
in the middle of text like this.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-04 12:17:18 -08:00
Kyle Meyer
04e5b3f0b4 submodule foreach: replace $path with $sm_path in example
f0fd0dc5c5 (submodule foreach: document '$sm_path' instead of '$path',
2018-05-08) updated the documentation to advise callers to favor
$sm_path over the deprecated synonym $path.  However, the example in
that section still uses $path.  Update it to use $sm_path.

Signed-off-by: Kyle Meyer <kyle@kyleam.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31 12:57:18 -08:00
Denton Liu
0ad7144999 .mailmap: map Yi-Jyun Pan's email
In 13185fd241 (l10n: zh_TW.po: update translation for v2.25.0 round 1,
2019-12-31), the author mistakenly used their GitHub username for
authorship information instead of their real name. However, a commit
with their real name exists prior to this: 9917eca794 (l10n: zh_TW: add
translation for v2.24.0, 2019-11-20).

Map their email to their real name so that these contributions can be
counted together.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-30 10:23:45 -08:00
Philippe Blain
c56c48dd07 grep: ignore --recurse-submodules if --no-index is given
Since grep learned to recurse into submodules in 0281e487fd
(grep: optionally recurse into submodules, 2016-12-16),
using --recurse-submodules along with --no-index makes Git
die().

This is unfortunate because if submodule.recurse is set in a user's
~/.gitconfig, invoking `git grep --no-index` either inside or outside
a Git repository results in

    fatal: option not supported with --recurse-submodules

Let's allow using these options together, so that setting submodule.recurse
globally does not prevent using `git grep --no-index`.

Using `--recurse-submodules` should not have any effect if `--no-index`
is used inside a repository, as Git will recurse into the checked out
submodule directories just like into regular directories.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-30 10:15:58 -08:00
Jeff King
cf82bff73f obstack: avoid computing offsets from NULL pointer
As with the previous two commits, UBSan with clang-11 complains about
computing offsets from a NULL pointer. The failures in t4013 (and
elsewhere) look like this:

  kwset.c:102:23: runtime error: applying non-zero offset 107820859019600 to null pointer
  ...
  not ok 79 - git log -SF master # magic is (not used)

That line is not enlightening:

  ... = obstack_alloc(&kwset->obstack, sizeof (struct trie));

because obstack is implemented almost entirely in macros, and the actual
problem is five macros deep (I temporarily converted them to inline
functions to get better compiler errors, which was tedious but worked
reasonably well).

The actual problem is in these pointer-alignment macros:

  /* If B is the base of an object addressed by P, return the result of
     aligning P to the next multiple of A + 1.  B and P must be of type
     char *.  A + 1 must be a power of 2.  */

  #define __BPTR_ALIGN(B, P, A) ((B) + (((P) - (B) + (A)) & ~(A)))

  /* Similar to _BPTR_ALIGN (B, P, A), except optimize the common case
     where pointers can be converted to integers, aligned as integers,
     and converted back again.  If PTR_INT_TYPE is narrower than a
     pointer (e.g., the AS/400), play it safe and compute the alignment
     relative to B.  Otherwise, use the faster strategy of computing the
     alignment relative to 0.  */

  #define __PTR_ALIGN(B, P, A)                                                \
    __BPTR_ALIGN (sizeof (PTR_INT_TYPE) < sizeof (void *) ? (B) : (char *) 0, \
                  P, A)

If we have a sufficiently-large integer pointer type, then we do the
computation using a NULL pointer constant. That turns __BPTR_ALIGN()
into something like:

  NULL + (P - NULL + A) & ~A

and UBSan is complaining about adding the full value of P to that
initial NULL. We can fix this by doing our math as an integer type, and
then casting the result back to a pointer. The problem case only happens
when we know that the integer type is large enough, so there should be
no issue with truncation.

Another option would be just simplify out all the 0's from
__BPTR_ALIGN() for the NULL-pointer case. That probably wouldn't work
for a platform where the NULL pointer isn't all-zeroes, but Git already
wouldn't work on such a platform (due to our use of memset to set
pointers in structs to NULL). But I tried here to keep as close to the
original as possible.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-28 23:13:25 -08:00
Jeff King
3cd309c16f xdiff: avoid computing non-zero offset from NULL pointer
As with the previous commit, clang-11's UBSan complains about computing
offsets from a NULL pointer, causing some tests to fail. In this case,
though, we're actually computing a non-zero offset, which is even more
dubious. From t7810:

  xdiff-interface.c:268:14: runtime error: applying non-zero offset 1 to null pointer
  ...
  not ok 131 - grep -p with userdiff

The problem is our parsing of the funcname config. We count the number
of lines in the string, allocate an array, and then loop over our
allocated entries, parsing each line and moving our cursor to one past
the trailing newline for the next iteration.

But the final line will not generally have a trailing newline (since
it's a config value), and hence we go to one past NULL. In practice this
is OK, since our loop should terminate before we look at the value. But
even computing such an invalid pointer technically violates the
standard.

We can fix it by leaving the pointer at NULL if we're at the end, rather
than one-past. And while we're thinking about it, we can also document
the variant by asserting that our initial line-count matches the
second-pass of parsing.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-28 23:13:25 -08:00
Jeff King
d20bc01a51 avoid computing zero offsets from NULL pointer
The Undefined Behavior Sanitizer in clang-11 seems to have learned a new
trick: it complains about computing offsets from a NULL pointer, even if
that offset is 0. This causes numerous test failures. For example, from
t1090:

  unpack-trees.c:1355:41: runtime error: applying zero offset to null pointer
  ...
  not ok 6 - in partial clone, sparse checkout only fetches needed blobs

The code in question looks like this:

  struct cache_entry **cache_end = cache + nr;
  ...
  while (cache != cache_end)

and we sometimes pass in a NULL and 0 for "cache" and "nr". This is
conceptually fine, as "cache_end" would be equal to "cache" in this
case, and we wouldn't enter the loop at all. But computing even a zero
offset violates the C standard. And given the fact that UBSan is
noticing this behavior, this might be a potential problem spot if the
compiler starts making unexpected assumptions based on undefined
behavior.

So let's just avoid it, which is pretty easy. In some cases we can just
switch to iterating with a numeric index (as we do in sequencer.c here).
In other cases (like the cache_end one) the use of an end pointer is
more natural; we can keep that by just explicitly checking for the
NULL/0 case when assigning the end pointer.

Note that there are two ways you can write this latter case, checking
for the pointer:

  cache_end = cache ? cache + nr : cache;

or the size:

  cache_end = nr ? cache + nr : cache;

For the case of a NULL/0 ptr/len combo, they are equivalent. But writing
it the second way (as this patch does) has the property that if somebody
were to incorrectly pass a NULL pointer with a non-zero length, we'd
continue to notice and segfault, rather than silently pretending the
length was zero.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-28 23:12:48 -08:00
David Turner
7edee32985 git rm submodule: succeed if .gitmodules index stat info is zero
The bug was that ie_match_stat() was used to compare if the stat info
for the file was compatible with the stat info in the index, rather
using ie_modified() to check if the file was in fact different from the
version in the index.

A version of this (with deinit instead of rm) was reported here:
https://lore.kernel.org/git/CAPOqYV+C-P9M2zcUBBkD2LALPm4K3sxSut+BjAkZ9T1AKLEr+A@mail.gmail.com/

It seems that in that case, the user's clone command left the index
with empty stat info.  The mailing list was unable to reproduce this.
But we (Two Sigma) hit the bug while using some plumbing commands, so
I'm fixing it.  I manually confirmed that the fix also repairs deinit
in this scenario.

Signed-off-by: David Turner <dturner@twosigma.com>
Reported-by: Thomas Bétous <th.betous@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-28 14:46:14 -08:00
Junio C Hamano
7210ca4ee5 .mailmap: fix GGG authoship screwup
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-27 13:19:53 -08:00
Jonathan Tan
b54128bb0b t5616: make robust to delta base change
Commit 6462d5eb9a ("fetch: remove fetch_if_missing=0", 2019-11-08)
contains a test that relies on having to lazily fetch the delta base of
a blob, but assumes that the tree being fetched (as part of the test) is
sent as a non-delta object. This assumption may not hold in the future;
for example, a change in the length of the object hash might result in
the tree being sent as a delta instead.

Make the test more robust by relying on having to lazily fetch the delta
base of the tree instead, and by making no assumptions on whether the
blobs are sent as delta or non-delta.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-27 12:42:40 -08:00
Junio C Hamano
4c616c2ba1 merge-recursive: use subtraction to flip stage
The flip_stage() helper uses a bit-flipping xor to switch between "2"
and "3". While clever, this relies on a property of those two numbers
that is mostly coincidence. Let's write it as a subtraction; that's more
clear and would extend to other numbers if somebody copies the logic.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-27 11:17:41 -08:00
Jeff King
ee798742bd merge-recursive: silence -Wxor-used-as-pow warning
The merge-recursive code uses stage number constants like this:

  add = &ci->ren1->dst_entry->stages[2 ^ 1];
  ...
  add = &ci->ren2->dst_entry->stages[3 ^ 1];

The xor has the effect of flipping the "1" bit, so that "2 ^ 1" becomes
"3" and "3 ^ 1" becomes "2", which correspond to the "ours" and "theirs"
stages respectively.

Unfortunately, clang-10 and up issue a warning for this code:

  merge-recursive.c:1759:40: error: result of '2 ^ 1' is 3; did you mean '1 << 1' (2)? [-Werror,-Wxor-used-as-pow]
                  add = &ci->ren1->dst_entry->stages[2 ^ 1];
                                                     ~~^~~
                                                     1 << 1
  merge-recursive.c:1759:40: note: replace expression with '0x2 ^ 1' to silence this warning

We could silence it by using 0x2, as the compiler mentions. Or by just
using the constants "2" and "3" directly. But after digging into it, I
do think this bit-flip is telling us something. If we just wrote:

  add = &ci->ren2->dst_entry->stages[2];

for the second one, you might think that "ren2" and "2" correspond. But
they don't. The logic is: ren2 is theirs, which is stage 3, but we
are interested in the opposite side's stage, so flip it to 2.

So let's keep the bit-flipping, but let's also put it behind a named
function, which will make its purpose a bit clearer. This also has the
side effect of suppressing the warning (and an optimizing compiler
should be able to easily turn it into a constant as before).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-27 11:15:35 -08:00
Denton Liu
a0ba80001a .mailmap: fix erroneous authorship for Johannes Schindelin
In 49e268e23e (mingw: safeguard better against backslashes in file
names, 2020-01-09), the commit author is listed as
"Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>", which
is erroneous. Fix the authorship by mapping the erroneous authorship to
his canonical authorship information.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-27 10:32:11 -08:00