Commit Graph

9007 Commits

Author SHA1 Message Date
Martin Ågren
bc62692757 hash-lookup: rename from sha1-lookup
Change all remnants of "sha1" in hash-lookup.c and .h and rename them to
reflect that we're not just able to handle SHA-1 these days.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-04 13:01:55 -08:00
Martin Ågren
7a7d992d0d sha1-lookup: rename sha1_pos() as hash_pos()
Rename this function to reflect that we're not just able to handle SHA-1
these days. There are a few instances of "sha1" left in sha1-lookup.[ch]
after this, but those will be addressed in the next commit.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-04 13:01:55 -08:00
Martin Ågren
e5afd4449d object-file.c: rename from sha1-file.c
Drop the last remnant of "sha1" in this file and rename it to reflect
that we're not just able to handle SHA-1 these days.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-04 13:01:55 -08:00
Junio C Hamano
7a50265295 Merge branch 'ma/maintenance-crontab-fix'
Hotfix for a topic of this cycle.

* ma/maintenance-crontab-fix:
  t7900-maintenance: test for magic markers
  gc: fix handling of crontab magic markers
  git-maintenance.txt: add missing word
2020-12-23 13:59:46 -08:00
Junio C Hamano
04cd999638 Merge branch 'dl/checkout-p-merge-base'
Fix to a regression introduced during this cycle.

* dl/checkout-p-merge-base:
  checkout -p: handle tree arguments correctly again
2020-12-23 13:59:46 -08:00
Junio C Hamano
c46f849f8a Merge branch 'jx/pack-redundant-on-single-pack'
"git pack-redandant" when there is only one packfile used to crash,
which has been corrected.

* jx/pack-redundant-on-single-pack:
  pack-redundant: fix crash when one packfile in repo
2020-12-23 13:59:46 -08:00
Martin Ågren
66dc0a3625 gc: fix handling of crontab magic markers
On `git maintenance start`, we add a few entries to the user's cron
table. We wrap our entries using two magic markers, "# BEGIN GIT
MAINTENANCE SCHEDULE" and "# END GIT MAINTENANCE SCHEDULE". At a later
`git maintenance stop`, we will go through the table and remove these
lines. Or rather, we will remove the "BEGIN" marker, the "END" marker
and everything between them.

Alas, we have a bug in how we detect the "END" marker: we don't. As we
loop through all the lines of the crontab, if we are in the "old
region", i.e., the region we're aiming to remove, we make an early
`continue` and don't get as far as checking for the "END" marker. Thus,
once we've seen our "BEGIN", we remove everything until the end of the
file.

Rewrite the logic for identifying these markers. There are four cases
that are mutually exclusive: The current line starts a region or it ends
it, or it's firmly within the region, or it's outside of it (and should
be printed).

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 14:33:08 -08:00
Johannes Schindelin
5c29f19cda checkout -p: handle tree arguments correctly again
This fixes a segmentation fault.

The bug is caused by dereferencing `new_branch_info->commit` when it is
`NULL`, which is the case when the tree-ish argument is actually a tree,
not a commit-ish. This was introduced in 5602b500c3 (builtin/checkout:
fix `git checkout -p HEAD...` bug, 2020-10-07), where we tried to ensure
that the special tree-ish `HEAD...` is handled correctly.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 14:06:09 -08:00
Eric Sunshine
cf76baea41 worktree: teach repair to fix multi-directional breakage
`git worktree repair` knows how to repair the two-way links between the
repository and a worktree as long as a link in one or the other
direction is sound. For instance, if a linked worktree is moved (without
using `git worktree move`), repair is possible because the worktree
still knows the location of the repository even though the repository no
longer knows where the worktree is. Similarly, if the repository is
moved, repair is possible since the repository still knows the locations
of the worktrees even though the worktrees no longer know where the
repository is.

However, if both the repository and the worktrees are moved, then links
are severed in both directions, and no repair is possible. This is the
case even when the new worktree locations are specified as arguments to
`git worktree repair`. The reason for this limitation is twofold. First,
when `repair` consults the worktree's gitfile (/path/to/worktree/.git)
to determine the corresponding <repo>/worktrees/<id>/gitdir file to fix,
<repo> is the old path to the repository, thus it is unable to fix the
`gitdir` file at its new location since it doesn't know where it is.
Second, when `repair` consults <repo>/worktrees/<id>/gitdir to find the
location of the worktree's gitfile (/path/to/worktree/.git), the path
recorded in `gitdir` is the old location of the worktree's gitfile, thus
it is unable to repair the gitfile since it doesn't know where it is.

Fix these shortcomings by teaching `repair` to attempt to infer the new
location of the <repo>/worktrees/<id>/gitdir file when the location
recorded in the worktree's gitfile has become stale but the file is
otherwise well-formed. The inference is intentionally simple-minded.
For each worktree path specified as an argument, `git worktree repair`
manually reads the ".git" gitfile at that location and, if it is
well-formed, extracts the <id>. It then searches for a corresponding
<id> in <repo>/worktrees/ and, if found, concludes that there is a
reasonable match and updates <repo>/worktrees/<id>/gitdir to point at
the specified worktree path. In order for <repo> to be known, `git
worktree repair` must be run in the main worktree or bare repository.

`git worktree repair` first attempts to repair each incoming
/path/to/worktree/.git gitfile to point at the repository, and then
attempts to repair outgoing <repo>/worktrees/<id>/gitdir files to point
at the worktrees. This sequence was chosen arbitrarily when originally
implemented since the order of fixes is immaterial as long as one side
of the two-way link between the repository and a worktree is sound.
However, for this new repair technique to work, the order must be
reversed. This is because the new inference mechanism, when it is
successful, allows the outgoing <repo>/worktrees/<id>/gitdir file to be
repaired, thus fixing one side of the two-way link. Once that side is
fixed, the other side can be fixed by the existing repair mechanism,
hence the order of repairs is now significant.

Two safeguards are employed to avoid hijacking a worktree from a
different repository if the user accidentally specifies a foreign
worktree as an argument. The first, as described above, is that it
requires an <id> match between the repository and the worktree. That
itself is not foolproof for preventing hijack, so the second safeguard
is that the inference will only kick in if the worktree's
/path/to/worktree/.git gitfile does not point at a repository.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 13:44:28 -08:00
Junio C Hamano
3517022568 Merge branch 'ab/unreachable-break'
Code clean-up.

* ab/unreachable-break:
  style: do not "break" in switch() after "return"
2020-12-18 15:15:18 -08:00
Junio C Hamano
772bdcd429 Merge branch 'js/init-defaultbranch-advice'
Our users are going to be trained to prepare for future change of
init.defaultBranch configuration variable.

* js/init-defaultbranch-advice:
  init: provide useful advice about init.defaultBranch
  get_default_branch_name(): prepare for showing some advice
  branch -m: allow renaming a yet-unborn branch
  init: document `init.defaultBranch` better
2020-12-18 15:15:17 -08:00
Junio C Hamano
21127fa982 Merge branch 'tb/partial-clone-filters-fix'
Fix potential server side resource deallocation issues when
responding to a partial clone request.

* tb/partial-clone-filters-fix:
  upload-pack.c: don't free allowed_filters util pointers
  builtin/clone.c: don't ignore transport_fetch_refs() errors
2020-12-17 15:06:40 -08:00
Jiang Xin
0696232390 pack-redundant: fix crash when one packfile in repo
Command `git pack-redundant --all` will crash if there is only one
packfile in the repository.  This is because, if there is only one
packfile in local_packs, `cmp_local_packs` will do nothing and will
leave `pl->unique_objects` as uninitialized.

Also add testcases for repository with no packfile and one packfile
in t5323.

Reported-by: Daniel C. Klauer <daniel.c.klauer@web.de>
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-16 21:21:06 -08:00
Felipe Contreras
c525de335e pull: display default warning only when non-ff
There's no need to display the annoying warning on every pull... only
the ones that are not fast-forward.

The current warning tests still pass, but not because of the arguments
or the configuration, but because they are all fast-forward.

We need to test non-fast-forward situations now.

Suggestions-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-15 17:39:42 -08:00
Junio C Hamano
7539fdc629 pull: correct condition to trigger non-ff advice
Refactor the advise() call that teaches users how they can choose
between merge and rebase into a helper function.  This revealed that
the caller's logic needs to be further clarified to allow future
actions (like "erroring out" instead of the current "go ahead and
merge anyway") that should happen whether the advice message is
squelched out.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-15 17:39:42 -08:00
Junio C Hamano
b044db9172 pull: get rid of unnecessary global variable
It is easy enough to do, and gives a more descriptive name to the
variable that is scoped in a more focused way.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-15 17:39:17 -08:00
Ævar Arnfjörð Bjarmason
56f56ac50b style: do not "break" in switch() after "return"
Remove this unreachable code. It was found by SunCC, it's found by a
non-fatal warning emitted by SunCC. It's one of the things it's more
vehement about than GCC & Clang.

It complains about a lot of other similarly unreachable code, e.g. a
BUG(...) without a "return", and a "return 0" after a long if/else,
both of whom have "return" statements. Those are also genuine
redundancies to a compiler, but arguably make the code a bit easier to
read & less fragile to maintain.

These return/break cases are just unnecessary however, and as seen
here the surrounding code just did a plain "return" without a "break"
already.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-15 16:32:50 -08:00
Junio C Hamano
c3b58472be pack-redundant: gauge the usage before proposing its removal
The subcommand is unusably slow and the reason why nobody reports it
as a performance bug is suspected to be the absense of users.  Let's
show a big message that asks the user to tell us that they still
care about the command when an attempt is made to run the command,
with an escape hatch to override it with a command line option.

In a few releases, we may turn it into an error and keep it for a
few more releases before finally removing it (during the whole time,
the plan to remove it would be interrupted by end user raising hand).

Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-15 14:30:11 -08:00
Felipe Contreras
278f4be806 pull: give the advice for choosing rebase/merge much later
Eventually we want to be omit the advice when we can fast-forward
in which case there is no reason to require the user to choose
between rebase or merge.

In order to do so, we need to delay giving the advice up to the
point where we can check if we can fast-forward or not.

Additionally, config_get_rebase() was probably never its true home.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-14 09:03:17 -08:00
Felipe Contreras
77a7ec6329 pull: refactor fast-forward check
We would like to be able to make this check before the decision to
rebase is made in a future step.  Besides, using a separate helper
makes the code easier to follow.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-14 08:59:40 -08:00
Johannes Schindelin
cc0f13c57d get_default_branch_name(): prepare for showing some advice
We are about to introduce a message giving users running `git init` some
advice about `init.defaultBranch`. This will necessarily be done in
`repo_default_branch_name()`.

Not all code paths want to show that advice, though. In particular, the
`git clone` codepath _specifically_ asks for `init_db()` to be quiet,
via the `INIT_DB_QUIET` flag.

In preparation for showing users above-mentioned advice, let's change
the function signature of `get_default_branch_name()` to accept the
parameter `quiet`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-13 15:53:50 -08:00
Johannes Schindelin
cfaff3aac8 branch -m: allow renaming a yet-unborn branch
In one of the next commits, we would like to give users some advice
regarding the initial branch name, and how to modify it.

To that end, it would be good if `git branch -m <name>` worked in a
freshly initialized repository without any commits. Let's make it so.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-13 15:53:50 -08:00
brian m. carlson
fac60b8925 rev-parse: add option for absolute or relative path formatting
git rev-parse has several options which print various paths.  Some of
these paths are printed relative to the current working directory, and
some are absolute.

Normally, this is not a problem, but there are times when one wants
paths entirely in one format or another.  This can be done trivially if
the paths are canonical, but canonicalizing paths is not possible on
some shell scripting environments which lack realpath(1) and also in Go,
which lacks functions that properly canonicalize paths on Windows.

To help out the scripter, let's provide an option which turns most of
the paths printed by git rev-parse to be either relative to the current
working directory or absolute and canonical.  Document which options are
affected and which are not so that users are not confused.

This approach is cleaner and tidier than providing duplicates of
existing options which are either relative or absolute.

Note that if the user needs both forms, it is possible to pass an
additional option in the middle of the command line which changes the
behavior of subsequent operations.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-12 23:35:51 -08:00
Junio C Hamano
bb48056cb2 Merge branch 'tb/bugreport-no-localtime'
Use of non-reentrant localtime() has been removed.

* tb/bugreport-no-localtime:
  builtin/bugreport.c: use thread-safe localtime_r()
2020-12-08 15:11:21 -08:00
Junio C Hamano
f2a75cb312 Merge branch 'rs/maintenance-run-outside-repo'
"git maintenance run/start/stop" needed to be run in a repository
to hold the lockfile they use, but didn't make sure they are
actually in a repository, which has been corrected.

* rs/maintenance-run-outside-repo:
  t7900: fix typo: "test_execpt_success"
  maintenance: fix SEGFAULT when no repository
2020-12-08 15:11:21 -08:00
Junio C Hamano
5dfb976460 Merge branch 'ma/grep-init-default'
Code clean-up.

* ma/grep-init-default:
  MyFirstObjectWalk: drop `init_walken_defaults()`
  grep: copy struct in one fell swoop
  grep: use designated initializers for `grep_defaults`
  grep: don't set up a "default" repo for grep
2020-12-08 15:11:20 -08:00
Junio C Hamano
01b8886a62 Merge branch 'js/trace2-session-id'
The transport layer was taught to optionally exchange the session
ID assigned by the trace2 subsystem during fetch/push transactions.

* js/trace2-session-id:
  receive-pack: log received client session ID
  send-pack: advertise session ID in capabilities
  upload-pack, serve: log received client session ID
  fetch-pack: advertise session ID in capabilities
  transport: log received server session ID
  serve: advertise session ID in v2 capabilities
  receive-pack: advertise session ID in v0 capabilities
  upload-pack: advertise session ID in v0 capabilities
  trace2: add a public function for getting the SID
  docs: new transfer.advertiseSID option
  docs: new capability to advertise session IDs
2020-12-08 15:11:20 -08:00
Junio C Hamano
d702cb9e89 Merge branch 'ds/maintenance-part-3'
"git maintenance" command had trouble working in a directory whose
pathname contained an ERE metacharacter like '+'.

* ds/maintenance-part-3:
  maintenance: use 'git config --fixed-value'
2020-12-08 15:11:19 -08:00
Junio C Hamano
a10e7842ab Merge branch 'ds/config-literal-value'
Various subcommands of "git config" that takes value_regex
learn the "--literal-value" option to take the value_regex option
as a literal string.

* ds/config-literal-value:
  config doc: value-pattern is not necessarily a regexp
  config: implement --fixed-value with --get*
  config: plumb --fixed-value into config API
  config: add --fixed-value option, un-implemented
  t1300: add test for --replace-all with value-pattern
  t1300: test "set all" mode with value-pattern
  config: replace 'value_regex' with 'value_pattern'
  config: convert multi_replace to flags
2020-12-08 15:11:19 -08:00
Junio C Hamano
1bc550effe Merge branch 'ps/update-ref-multi-transaction'
"git update-ref --stdin" learns to take multiple transactions in a
single session.

* ps/update-ref-multi-transaction:
  update-ref: disallow "start" for ongoing transactions
  p1400: use `git-update-ref --stdin` to test multiple transactions
  update-ref: allow creation of multiple transactions
  t1400: avoid touching refs on filesystem
2020-12-08 15:11:17 -08:00
Jeff King
449fa5ee06 pack-bitmap-write: ignore BITMAP_FLAG_REUSE
The on-disk bitmap format has a flag to mark a bitmap to be "reused".
This is a rather curious feature, and works like this:

  - a run of pack-objects would decide to mark the last 80% of the
    bitmaps it generates with the reuse flag

  - the next time we generate bitmaps, we'd see those reuse flags from
    the last run, and mark those commits as special:

      - we'd be more likely to select those commits to get bitmaps in
        the new output

      - when generating the bitmap for a selected commit, we'd reuse the
        old bitmap as-is (rearranging the bits to match the new pack, of
        course)

However, neither of these behaviors particularly makes sense.

Just because a commit happened to be bitmapped last time does not make
it a good candidate for having a bitmap this time. In particular, we may
choose bitmaps based on how recent they are in history, or whether a ref
tip points to them, and those things will change. We're better off
re-considering fresh which commits are good candidates.

Reusing the existing bitmap _is_ a reasonable thing to do to save
computation. But only reusing exact bitmaps is a weak form of this. If
we have an old bitmap for A and now want a new bitmap for its child, we
should be able to compute that only by looking at trees and that are new
to the child. But this code would consider only exact reuse (which is
perhaps why it was eager to select those commits in the first place).

Furthermore, the recent switch to the reverse-edge algorithm for
generating bitmaps dropped this optimization entirely (and yet still
performs better).

So let's do a few cleanups:

 - drop the whole "reusing bitmaps" phase of generating bitmaps. It's
   not helping anything, and is mostly unused code (or worse, code that
   is using CPU but not doing anything useful)

 - drop the use of the on-disk reuse flag to select commits to bitmap

 - stop setting the on-disk reuse flag in bitmaps we generate (since
   nothing respects it anymore)

We will keep a few innards of the reuse code, which will help us
implement a more capable version of the "reuse" optimization:

 - simplify rebuild_existing_bitmaps() into a function that only builds
   the mapping of bits between the old and new orders, but doesn't
   actually convert any bitmaps

 - make rebuild_bitmap() public; we'll call it lazily to convert bitmaps
   as we traverse (using the mapping created above)

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-08 14:48:17 -08:00
Taylor Blau
aab179d937 builtin/clone.c: don't ignore transport_fetch_refs() errors
If 'git clone' couldn't execute 'transport_fetch_refs()' (e.g., because
of an error on the remote's side in 'git upload-pack'), then it will
silently ignore it.

Even though this has been the case at least since clone was ported to C
(way back in 8434c2f1af (Build in clone, 2008-04-27)), 'git fetch'
doesn't ignore these and reports any failures it sees.

That suggests that ignoring the return value in 'git clone' is simply an
oversight that should be corrected. That's exactly what this patch does.
(Noticing and fixing this is no coincidence, we'll want it in the next
patch in order to demonstrate a regression in 'git upload-pack' via a
'git clone'.)

There's no additional logging here, but that matches how 'git fetch'
handles the same case. An assumption there is that whichever part of
transport_fetch_refs() fails will complain loudly, so any additional
logging here is redundant.

Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-03 12:42:29 -08:00
Junio C Hamano
39d38a5c5f Merge branch 'tb/repack-simplify'
Simplify the logic to deal with a repack operation that ended up
creating the same packfile.

* tb/repack-simplify:
  builtin/repack.c: don't move existing packs out of the way
  builtin/repack.c: keep track of what pack-objects wrote
  repack: make "exts" array available outside cmd_repack()
2020-12-03 00:18:06 -08:00
Junio C Hamano
c692e1b673 Merge branch 'pb/pull-rebase-recurse-submodules'
"git pull --rebase --recurse-submodules" checked for local changes
in a wrong range and failed to run correctly when it should.

* pb/pull-rebase-recurse-submodules:
  pull: check for local submodule modifications with the right range
  t5572: describe '--rebase' tests a little more
  t5572: add notes on a peculiar test
  pull --rebase: compute rebase arguments in separate function
2020-12-03 00:18:06 -08:00
Elijah Newren
ba359fd507 stash: fix stash application in sparse-checkouts
sparse-checkouts are built on the patterns in the
$GIT_DIR/info/sparse-checkout file, where commands have modified
behavior for paths that do not match those patterns.  The differences in
behavior, as far as the bugs concerned here, fall into three different
categories (with git subcommands that fall into each category listed):

  * commands that only look at files matching the patterns:
      * status
      * diff
      * clean
      * update-index
  * commands that remove files from the working tree that do not match
    the patterns, and restore files that do match them:
      * read-tree
      * switch
      * checkout
      * reset (--hard)
  * commands that omit writing files to the working tree that do not
    match the patterns, unless those files are not clean:
      * merge
      * rebase
      * cherry-pick
      * revert

There are some caveats above, e.g. a plain `git diff` ignores files
outside the sparsity patterns but will show diffs for paths outside the
sparsity patterns when revision arguments are passed.  (Technically,
diff is treating the sparse paths as matching HEAD.)  So, there is some
internal inconsistency among these commands.  There are also additional
commands that should behave differently in the face of sparse-checkouts,
as the sparse-checkout documentation alludes to, but the above is
sufficient for me to explain how `git stash` is affected.

What is relevant here is that logically 'stash' should behave like a
merge; it three-way merges the changes the user had in progress at stash
creation time, the HEAD at the time the stash was created, and the
current HEAD, in order to get the stashed changes applied to the current
branch.  However, this simplistic view doesn't quite work in practice,
because stash tweaks it a bit due to two factors: (1) flags like
--keep-index and --include-untracked (why we used two different verbs,
'keep' and 'include', is a rant for another day) modify what should be
staged at the end and include more things that should be quasi-merged,
(2) stash generally wants changes to NOT be staged.  It only provides
exceptions when (a) some of the changes had conflicts and thus we want
to use stages to denote the clean merges and higher order stages to
mark the conflicts, or (b) if there is a brand new file we don't want
it to become untracked.

stash has traditionally gotten this special behavior by first doing a
merge, and then when it's clean, applying a pipeline of commands to
modify the result.  This series of commands for
unstaging-non-newly-added-files came from the following commands:

    git diff-index --cached --name-only --diff-filter=A $CTREE >"$a"
    git read-tree --reset $CTREE
    git update-index --add --stdin <"$a"
    rm -f "$a"

Looking back at the different types of special sparsity handling listed
at the beginning of this message, you may note that we have at least one
of each type covered here: merge, diff-index, and read-tree.  The weird
mix-and-match led to 3 different bugs:

(1) If a path merged cleanly and it didn't match the sparsity patterns,
the merge backend would know to avoid writing it to the working tree and
keep the SKIP_WORKTREE bit, simply only updating it in the index.
Unfortunately, the subsequent commands would essentially undo the
changes in the index and thus simply toss the changes altogether since
there was nothing left in the working tree.  This means the stash is
only partially applied.

(2) If a path existed in the worktree before `git stash apply` despite
having the SKIP_WORKTREE bit set, then the `git read-tree --reset` would
print an error message of the form
      error: Entry 'modified' not uptodate. Cannot merge.
and cause stash to abort early.

(3) If there was a brand new file added by the stash, then the
diff-index command would save that pathname to the temporary file, the
read-tree --reset would remove it from the index, and the update-index
command would barf due to no such file being present in the working
copy; it would print a message of the form:
      error: NEWFILE: does not exist and --remove not passed
      fatal: Unable to process path NEWFILE
and then cause stash to abort early.

Basically, the whole idea of unstage-unless-brand-new requires special
care when you are dealing with a sparse-checkout.  Fix these problems
by applying the following simple rule:

  When we unstage files, if they have the SKIP_WORKTREE bit set,
  clear that bit and write the file out to the working directory.

  (*) If there's already a file present in the way, rename it first.

This fixes all three problems in t7012.13 and allows us to mark it as
passing.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-01 14:39:04 -08:00
Elijah Newren
b34ab4a43b stash: remove unnecessary process forking
When stash was converted from shell to a builtin, it merely
transliterated the forking of various git commands from shell to a C
program that would fork the same commands.  Some of those were converted
over to actual library calls, but much of the pipeline-of-commands
design still remains.  Fix some of this by replacing the portion
corresponding to

    git diff-index --cached --name-only --diff-filter=A $CTREE >"$a"
    git read-tree --reset $CTREE
    git update-index --add --stdin <"$a"
    rm -f "$a"

into a library function that does the same thing.  (The read-tree
--reset was already partially converted over to a library call, but as
an independent piece.)  Note here that this came after a merge operation
was performed.  The merge machinery always stages anything that cleanly
merges, and the above code only runs if there are no conflicts.  Its
purpose is to make it so that when there are no conflicts, all the
changes from the stash are unstaged.  However, that causes brand new
files from the stash to become untracked, so the code above first saves
those files off and then re-adds them afterwards.

We replace the whole series of commands with a simple function that will
unstage files that are not newly added.  This doesn't fix any bugs in
the usage of these commands, it simply matches the existing behavior but
makes it into a single atomic operation that we can then operate on as a
whole.  A subsequent commit will take advantage of this to fix issues
with these commands in sparse-checkouts.

This conversion incidentally fixes t3906.1, because the separate
update-index process would die with the following error messages:
    error: uninitialized_sub: is a directory - add files inside instead
    fatal: Unable to process path uninitialized_sub
The unstaging of the directory as a submodule meant it was no longer
tracked, and thus as an uninitialized directory it could not be added
back using `git update-index --add`, thus resulting in this error and
early abort.  Most of the submodule tests in 3906 continue to fail after
this change, this change was just enough to push the first of those
tests to success.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-01 14:39:04 -08:00
Taylor Blau
4f6460df55 builtin/bugreport.c: use thread-safe localtime_r()
To generate its filename, the 'git bugreport' builtin asks the system
for the current time with 'localtime()'. Since this uses a shared
buffer, it is not thread-safe.

Even though 'git bugreport' is not multi-threaded, using localtime() can
trigger some static analysis tools to complain, and a quick

    $ git grep -oh 'localtime\(_.\)\?' -- **/*.c | sort | uniq -c

shows that the only usage of the thread-unsafe 'localtime' is in a piece
of documentation.

So, convert this instance to use the thread-safe version for
consistency, and to appease some analysis tools.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-01 13:05:37 -08:00
Junio C Hamano
3d8f81f21b Merge branch 'sa/credential-store-timeout'
Multiple "credential-store" backends can race to lock the same
file, causing everybody else but one to fail---reattempt locking
with some timeout to reduce the rate of the failure.

* sa/credential-store-timeout:
  crendential-store: use timeout when locking file
2020-11-30 14:49:45 -08:00
Junio C Hamano
fa27e2d103 Merge branch 'km/stash-error-message-fix'
Error message fix.

* km/stash-error-message-fix:
  stash: add missing space to an error message
2020-11-30 14:49:45 -08:00
Junio C Hamano
f73ee0c6be Merge branch 'mt/worktree-error-message-fix'
Fix formulation of an error message with two placeholders in "git
worktree add" subcommand.

* mt/worktree-error-message-fix:
  worktree: fix order of arguments in error message
2020-11-30 14:49:43 -08:00
Junio C Hamano
1c04cdd424 Merge branch 'ab/gc-keep-base-option'
Fix an option name in "gc" documentation.

* ab/gc-keep-base-option:
  gc: rename keep_base_pack variable for --keep-largest-pack
  gc docs: change --keep-base-pack to --keep-largest-pack
2020-11-30 14:49:43 -08:00
Junio C Hamano
290c94085b Merge branch 'js/pull-rebase-use-advise'
UI improvement.

* js/pull-rebase-use-advise:
  pull: colorize the hint about setting `pull.rebase`
2020-11-30 14:49:42 -08:00
Rafael Silva
e72f7defc4 maintenance: fix SEGFAULT when no repository
The "git maintenance run" and "git maintenance start/stop" commands
holds a file-based lock at the .git/maintenance.lock and
.git/schedule.lock respectively. These locks are used to ensure only
one maintenance process is executed at the time as both operations
involves writing data into the git repository.

The path to the lock file is built using
"the_repository->objects->odb->path" that results in SEGFAULT when we
have no repository available as "the_repository->objects->odb" is
set to NULL.

Let's teach maintenance command to use RUN_SETUP option that will
provide the validation and fail when running outside of a repository.
Hence fixing the SEGFAULT for all three operations and making the
behaviour consistent across all subcommands.

Setting the RUN_SETUP also provides the same protection for all
subcommands given that the "register" and "unregister" also requires to
be executed inside a repository.

Furthermore let's remove the local validation implemented by the
"register" and "unregister" as this will not be required anymore with
the new option.

Signed-off-by: Rafael Silva <rafaeloliveira.cs@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-30 13:44:15 -08:00
Junio C Hamano
2ba70a330b Merge branch 'rs/gc-sort-func-cast-fix'
Fix broken sorting of maintenance tasks.

* rs/gc-sort-func-cast-fix:
  gc: fix cast in compare_tasks_by_selection()
2020-11-25 15:24:53 -08:00
Junio C Hamano
fcf26ef53a Merge branch 'jk/4gb-idx'
The code was not prepared to deal with pack .idx file that is
larger than 4GB.

* jk/4gb-idx:
  packfile: detect overflow in .idx file size checks
  block-sha1: take a size_t length parameter
  fsck: correctly compute checksums on idx files larger than 4GB
  use size_t to store pack .idx byte offsets
  compute pack .idx byte offsets using size_t
2020-11-25 15:24:52 -08:00
Junio C Hamano
8f8f10ac09 Merge branch 'jx/t5411-flake-fix'
The exchange between receive-pack and proc-receive hook did not
carefully check for errors.

* jx/t5411-flake-fix:
  receive-pack: use default version 0 for proc-receive
  receive-pack: gently write messages to proc-receive
  t5411: new helper filter_out_user_friendly_and_stable_output
2020-11-25 15:24:52 -08:00
Derrick Stolee
483a6d9b5d maintenance: use 'git config --fixed-value'
When a repository's leading directories contain regex metacharacters,
the config calls for 'git maintenance register' and 'git maintenance
unregister' are not careful enough. Use the new --fixed-value option
to direct the config machinery to use exact string matches. This is a
more robust option than escaping these arguments in a piecemeal fashion.

For the test, require that we are not running on Windows since the '+'
and '*' characters are not allowed on that filesystem.

Reported-by: Emily Shaffer <emilyshaffer@google.com>
Reported-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 15:04:55 -08:00
Derrick Stolee
3f1bae1dc3 config: implement --fixed-value with --get*
The config builtin does its own regex matching of values for the --get,
--get-all, and --get-regexp modes. Plumb the existing 'flags' parameter
to the get_value() method so we can initialize the value-pattern argument
as a fixed string instead of a regex pattern.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 14:43:48 -08:00
Derrick Stolee
c90702a1f6 config: plumb --fixed-value into config API
The git_config_set_multivar_in_file_gently() and related methods now
take a 'flags' bitfield, so add a new bit representing the --fixed-value
option from 'git config'. This alters the purpose of the value_pattern
parameter to be an exact string match. This requires some initialization
changes in git_config_set_multivar_in_file_gently() and a new strcmp()
call in the matches() method.

The new CONFIG_FLAGS_FIXED_VALUE flag is initialized in builtin/config.c
based on the --fixed-value option, and that needs to be updated in
several callers.

This patch only affects some of the modes of 'git config', and the rest
will be completed in the next change.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 14:43:48 -08:00
Derrick Stolee
fda43942d7 config: add --fixed-value option, un-implemented
The 'git config' builtin takes a 'value-pattern' parameter for several
actions. This can cause confusion when expecting exact value matches
instead of regex matches, especially when the input string contains
metacharacters. While callers can escape the patterns themselves, it
would be more friendly to allow an argument to disable the pattern
matching in favor of an exact string match.

Add a new '--fixed-value' option that does not currently change the
behavior. The implementation will be filled in by later changes for
each appropriate action. For now, check and test that --fixed-value
will abort the command when included with an incompatible action or
without a 'value-pattern' argument.

The name '--fixed-value' was chosen over something simpler like
'--fixed' because some commands allow regular expressions on the
key in addition to the value.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 14:43:48 -08:00
Derrick Stolee
247e2f822e config: replace 'value_regex' with 'value_pattern'
The 'value_regex' argument in the 'git config' builtin is poorly named,
especially related to an upcoming change that allows exact string
matches instead of ERE pattern matches.

Perform a mostly mechanical change of every instance of 'value_regex' to
'value_pattern' in the codebase. This is only critical for documentation
and error messages, but it is best to be consistent inside the codebase,
too.

For documentation, use 'value-pattern' which is better punctuation. This
affects Documentation/git-config.txt and the usage in builtin/config.c,
which was already mixed between 'value_regex' and 'value-regex'.

I gave some thought to leaving the value_regex variables inside config.c
that are regex_t pointers. However, it is probably best to keep the name
consistent with the rest of the variables.

This does not update the translations inside the po/ directory, as that
creates conflicts with ongoing work. The input strings should
automatically update through automation, and a few of the output strings
currently use "[value_regex]" directly.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 14:43:48 -08:00
Derrick Stolee
504ee1290e config: convert multi_replace to flags
We will extend the flexibility of the config API. Before doing so, let's
take an existing 'int multi_replace' parameter and replace it with a new
'unsigned flags' parameter that can take multiple options as a bit field.

Update all callers that specified multi_replace to now specify the
CONFIG_FLAGS_MULTI_REPLACE flag. To add more clarity, extend the
documentation of git_config_set_multivar_in_file() including a clear
labeling of its arguments. Other config API methods in config.h require
only a change of the final parameter from 'int' to 'unsigned'.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 14:43:47 -08:00
Simão Afonso
df7f915fb6 crendential-store: use timeout when locking file
When holding the lock for rewriting the credential file, use a timeout
to avoid race conditions when the credentials file needs to be updated
in parallel.

An example would be doing `fetch --all` on a repository with several
remotes that need credentials, using parallel fetching.

The timeout can be configured using "credentialStore.lockTimeoutMS",
defaulting to 1 second.

Signed-off-by: Simão Afonso <simao.afonso@powertools-tech.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 12:30:18 -08:00
Derrick Stolee
31345d5545 maintenance: extract platform-specific scheduling
The existing schedule mechanism using 'cron' is supported by POSIX
platforms, but not Windows. It also works slightly differently on
macOS to significant detriment of the user experience. To allow for
new implementations on these platforms, extract a method that
performs the platform-specific scheduling mechanism. This will be
swapped at compile time with new implementations on specialized
platforms.

As we add this generality, rename GIT_TEST_CRONTAB to
GIT_TEST_MAINT_SCHEDULER. Further, this variable is now parsed as
"<scheduler>:<command>" so we can test platform-specific scheduling
logic even when not on the correct platform. By specifying the
<scheduler> in this string, we will be able to test all three sets of
Git logic from a Linux machine.

Co-authored-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-24 13:02:29 -08:00
Kyle Meyer
eaf5341538 stash: add missing space to an error message
Restore a space that was lost in 8a0fc8d19d (stash: convert apply to
builtin, 2019-02-25).

Signed-off-by: Kyle Meyer <kyle@kyleam.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-24 12:56:31 -08:00
Junio C Hamano
bf0a430f70 Merge branch 'en/strmap'
A specialization of hashmap that uses a string as key has been
introduced.  Hopefully it will see wider use over time.

* en/strmap:
  shortlog: use strset from strmap.h
  Use new HASHMAP_INIT macro to simplify hashmap initialization
  strmap: take advantage of FLEXPTR_ALLOC_STR when relevant
  strmap: enable allocations to come from a mem_pool
  strmap: add a strset sub-type
  strmap: split create_entry() out of strmap_put()
  strmap: add functions facilitating use as a string->int map
  strmap: enable faster clearing and reusing of strmaps
  strmap: add more utility functions
  strmap: new utility functions
  hashmap: provide deallocation function names
  hashmap: introduce a new hashmap_partial_clear()
  hashmap: allow re-use after hashmap_free()
  hashmap: adjust spacing to fix argument alignment
  hashmap: add usage documentation explaining hashmap_free[_entries]()
2020-11-21 15:14:38 -08:00
Junio C Hamano
0dd171f0bc Merge branch 'jk/rev-parse-end-of-options'
"git rev-parse" learned the "--end-of-options" to help scripts to
safely take a parameter that is supposed to be a revision, e.g.
"git rev-parse --verify -q --end-of-options $rev".

* jk/rev-parse-end-of-options:
  rev-parse: handle --end-of-options
  rev-parse: put all options under the "-" check
  rev-parse: don't accept options after dashdash
2020-11-21 15:14:38 -08:00
Junio C Hamano
473c6224c6 Merge branch 'jc/format-patch-name-max'
The maximum length of output filenames "git format-patch" creates
has become configurable (used to be capped at 64).

* jc/format-patch-name-max:
  format-patch: make output filename configurable
2020-11-21 15:14:38 -08:00
Martin Ågren
96313423a7 grep: use designated initializers for grep_defaults
In 15fabd1bbd ("builtin/grep.c: make configuration callback more
reusable", 2012-10-09), we learned to fill a `static struct grep_opt
grep_defaults` which we can use as a blueprint for other such structs.

At the time, we didn't consider designated initializers to be widely
useable, but these days, we do. (See, e.g., cbc0f81d96 ("strbuf: use
designated initializers in STRBUF_INIT", 2017-07-10).)

Use designated initializers to let the compiler set up the struct and so
that we don't need to remember to call `init_grep_defaults()`.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-21 14:50:33 -08:00
Martin Ågren
1d3878799f grep: don't set up a "default" repo for grep
`init_grep_defaults()` fills a `static struct grep_opt grep_defaults`.
This struct is then used by `grep_init()` as a blueprint for other such
structs. Notably, `grep_init()` takes a `struct repo *` and assigns it
into the target struct.

As a result, it is unnecessary for us to take a `struct repo *` in
`init_grep_defaults()` as well. We assign it into the default struct and
never look at it again. And in light of how we return early if we have
already set up the default struct, it's not just unnecessary, but is
also a bit confusing: If we are called twice and with different repos,
is it a bug or a feature that we ignore the second repo?

Drop the repo parameter for `init_grep_defaults()`.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-21 14:50:29 -08:00
Matheus Tavares
b86339b12b worktree: fix order of arguments in error message
`git worktree add` (without --force) errors out when given a path
that is already registered as a worktree and the path is missing on
disk. But the `cmd` and `path` strings are switched on the error
message. Let's fix that.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-21 13:31:34 -08:00
Ævar Arnfjörð Bjarmason
793c1464d3 gc: rename keep_base_pack variable for --keep-largest-pack
As noted in an earlier change the keep_base_pack variable name is a
relic from an earlier on-list version of ae4e89e549 ("gc: add
--keep-largest-pack option", 2018-04-15) before it was renamed to
--keep-largest-pack.

Let's change the variable name to avoid that confusion, it's easier to
read the code if there's a 1=1 mapping between the variable name and
option name.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-21 11:39:59 -08:00
Johannes Schindelin
e01ae2a4a7 pull: colorize the hint about setting pull.rebase
In d18c950a69 (pull: warn if the user didn't say whether to rebase or
to merge, 2020-03-09), a new hint was introduced to encourage users to
make a conscious decision about whether they want their pull to merge or
to rebase by configuring the `pull.rebase` setting.

This warning was clearly intended to advise users, but as pointed out in
https://lore.kernel.org/git/87ima2rdsm.fsf%40evledraar.gmail.com, it
uses `warning()` instead of `advise()`.

One consequence is that the advice is not colorized in the same manner
as other, similar messages. So let's use `advise()` instead.

Pointed-out-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-19 14:13:30 -08:00
René Scharfe
a1c74791d5 gc: fix cast in compare_tasks_by_selection()
compare_tasks_by_selection() is used with QSORT and gets passed pointers
to the elements of "static struct maintenance_task tasks[]".  It casts
the *addresses* of these passed pointers to element pointers, though,
and thus effectively compares some unrelated values from the stack.  Fix
the casts to actually compare array elements.

Detected by USan (make SANITIZE=undefined test).

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-18 14:15:58 -08:00
Junio C Hamano
3f6dc9c366 Merge branch 'pb/blame-funcname-range-userdiff'
"git blame -L :funcname -- path" did not work well for a path for
which a userdiff driver is defined.

* pb/blame-funcname-range-userdiff:
  blame: simplify 'setup_blame_bloom_data' interface
  blame: simplify 'setup_scoreboard' interface
  blame: enable funcname blaming with userdiff driver
  line-log: mention both modes in 'blame' and 'log' short help
  doc: add more pointers to gitattributes(5) for userdiff
  blame-options.txt: also mention 'funcname' in '-L' description
  doc: line-range: improve formatting
  doc: log, gitk: move '-L' description to 'line-range-options.txt'
2020-11-18 13:32:53 -08:00
Junio C Hamano
a1f95951ef Merge branch 'en/merge-ort-api-null-impl'
Preparation for a new merge strategy.

* en/merge-ort-api-null-impl:
  merge,rebase,revert: select ort or recursive by config or environment
  fast-rebase: demonstrate merge-ort's API via new test-tool command
  merge-ort-wrappers: new convience wrappers to mimic the old merge API
  merge-ort: barebones API of new merge strategy with empty implementation
2020-11-18 13:32:53 -08:00
Junio C Hamano
7660da1618 Merge branch 'ds/maintenance-part-3'
Parts of "git maintenance" to ease writing crontab entries (and
other scheduling system configuration) for it.

* ds/maintenance-part-3:
  maintenance: add troubleshooting guide to docs
  maintenance: use 'incremental' strategy by default
  maintenance: create maintenance.strategy config
  maintenance: add start/stop subcommands
  maintenance: add [un]register subcommands
  for-each-repo: run subcommands on configured repos
  maintenance: add --schedule option and config
  maintenance: optionally skip --auto process
2020-11-18 13:32:53 -08:00
Junio C Hamano
c042c455d4 Merge branch 'pw/rebase-i-orig-head'
"git rebase -i" did not store ORIG_HEAD correctly.

* pw/rebase-i-orig-head:
  rebase -i: simplify get_revision_ranges()
  rebase -i: use struct object_id when writing state
  rebase -i: use struct object_id rather than looking up commit
  rebase -i: stop overwriting ORIG_HEAD buffer
2020-11-18 13:32:53 -08:00
Junio C Hamano
5edc8bdc06 Merge branch 'jk/format-patch-output'
"git format-patch --output=there" did not work as expected and
instead crashed.  The option is now supported.

* jk/format-patch-output:
  format-patch: support --output option
  format-patch: tie file-opening logic to output_directory
  format-patch: refactor output selection
2020-11-18 13:32:52 -08:00
Junio C Hamano
f8a1cee7b3 Merge branch 'jc/line-log-takes-no-pathspec'
"git log -L<range>:<path>" is documented to take no pathspec, but
this was not enforced by the command line option parser, which has
been corrected.

* jc/line-log-takes-no-pathspec:
  log: diagnose -L used with pathspec as an error
2020-11-18 13:32:52 -08:00
Junio C Hamano
30f5257611 Merge branch 'rs/empty-reflog-check-fix'
The code to see if "git stash drop" can safely remove refs/stash
has been made more carerful.

* rs/empty-reflog-check-fix:
  stash: simplify reflog emptiness check
2020-11-18 13:32:52 -08:00
Taylor Blau
2fcb03b52d builtin/repack.c: don't move existing packs out of the way
When 'git repack' creates a pack with the same name as any existing
pack, it moves the existing one to 'old-pack-xxx.{pack,idx,...}' and
then renames the new one into place.

Eventually, it would be nice to have 'git repack' allow for writing a
multi-pack index at the critical time (after the new packs have been
written / moved into place, but before the old ones have been deleted).
Guessing that this option might be called '--write-midx', this makes the
following situation (where repacks are issued back-to-back without any
new objects) impossible:

    $ git repack -adb
    $ git repack -adb --write-midx

In the second repack, the existing packs are overwritten verbatim with
the same rename-to-old sequence. At that point, the current MIDX is
invalidated, since it refers to now-missing packs. So that code wants to
be run after the MIDX is re-written. But (prior to this patch) the new
MIDX can't be written until the new packs are moved into place. So, we
have a circular dependency.

This is all hypothetical, since no code currently exists to write a MIDX
safely during a 'git repack' (the 'GIT_TEST_MULTI_PACK_INDEX' does so
unsafely). Putting hypothetical aside, though: why do we need to rename
existing packs to be prefixed with 'old-' anyway?

This behavior dates all the way back to 2ad47d6 (git-repack: Be
careful when updating the same pack as an existing one., 2006-06-25).
2ad47d6 is mainly concerned about a case where a newly written pack
would have a different structure than its index. This used to be
possible when the pack name was a hash of the set of objects. Under this
naming scheme, two packs that store the same set of objects could differ
in delta selection, object positioning, or both. If this happened, then
any such packs would be unreadable in the instant between copying the
new pack and new index (i.e., either the index or pack will be stale
depending on the order that they were copied).

But since 1190a1a (pack-objects: name pack files after trailer hash,
2013-12-05), this is no longer possible, since pack files are named not
after their logical contents (i.e., the set of objects), but by the
actual checksum of their contents. So, this old- behavior can safely go,
which allows us to avoid our circular dependency above.

In addition to avoiding the circular dependency, this patch also makes
'git repack' a lot simpler, since we don't have to deal with failures
encountered when renaming existing packs to be prefixed with 'old-'.

This patch is mostly limited to removing code paths that deal with the
'old' prefixing, with the exception of files that include the pack's
name in their own filename, like .idx, .bitmap, and related files. The
exception is that we want to continue to trust what pack-objects wrote.
That is, it is not the case that we pretend as if pack-objects didn't
write files identical to ones that already exist, but rather that we
respect what pack-objects wrote as the source of truth. That cuts two
ways:

  - If pack-objects produced an identical pack to one that already
    exists with a bitmap, but did not produce a bitmap, we remove the
    bitmap that already exists. (This behavior is codified in t7700.14).

  - If pack-objects produced an identical pack to one that already
    exists, we trust the just-written version of the coresponding .idx,
    .promisor, and other files over the ones that already exist. This
    ensures that we use the most up-to-date versions of this files,
    which is safe even in the face of format changes in, say, the .idx
    file (which would not be reflected in the .idx file's name).

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-17 13:31:55 -08:00
Philippe Blain
5176f20ffe pull: check for local submodule modifications with the right range
Ever since 'git pull' learned '--recurse-submodules' in a6d7eb2c7a
(pull: optionally rebase submodules (remote submodule changes only),
2017-06-23), we check if there are local submodule modifications by
checking the revision range 'curr_head --not rebase_fork_point'.

The goal of this check is to abort the pull if there are submodule
modifications in the local commits being rebased, since this scenario is
not supported.

However, the actual range of commits being rebased is not
'rebase_fork_point..curr_head', as the logic in
'get_rebase_newbase_and_upstream' reveals, it is 'upstream..curr_head'.

If the 'git merge-base --fork-point' invocation in
'get_rebase_fork_point' fails to find a fork point between the current
branch and the remote-tracking branch we are pulling from,
'rebase_fork_point' is null and since 4d36f88be7 (submodule: do not pass
null OID to setup_revisions, 2018-05-24), 'submodule_touches_in_range'
checks 'curr_head' and all its ancestors for submodule modifications.

Since it is highly likely that there are submodule modifications in this
range (which is in effect the whole history of the current branch), this
prevents 'git pull --rebase --recurse-submodules' from succeeding if no
fork point exists between the current branch and the remote-tracking
branch being pulled. This can happen, for example, when the current
branch was forked from a commit which was never recorded in the reflog
of the remote-tracking branch we are pulling, as the last two paragraphs
of the "Discussion on fork-point mode" section in git-merge-base(1)
explain.

Fix this bug by passing 'upstream' instead of 'rebase_fork_point' as the
'excl_oid' argument to 'submodule_touches_in_range'.

Reported-by: Brice Goglin <bgoglin@free.fr>
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-16 16:01:13 -08:00
Philippe Blain
4f66d79ae3 pull --rebase: compute rebase arguments in separate function
The function 'run_rebase' is responsible for constructing the
command line to be passed to 'git rebase'. This includes both forwarding
pass-through options given to 'git pull' as well computing the <newbase>
and <upstream> arguments to 'git rebase'.

A following commit will need to access the <upstream> argument in
'cmd_pull' to fix a bug with 'git pull --rebase --recurse-submodules'.
In order to do so, refactor the code so that the <newbase> and
<upstream> commits are computed in a new, separate function,
'get_rebase_newbase_and_upstream'.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-16 16:01:13 -08:00
Taylor Blau
704c4a5c07 builtin/repack.c: keep track of what pack-objects wrote
In the subsequent commit, it will become useful to keep track of which
metadata files were written by pack-objects. We already do this to an
extent with the 'exts' array, which only is used in the context of
existing packs.

Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-16 15:57:44 -08:00
Jeff King
63f4d5cf57 repack: make "exts" array available outside cmd_repack()
We'll use it in a helper function soon.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-16 15:57:43 -08:00
Patrick Steinhardt
8c4417f1cf update-ref: disallow "start" for ongoing transactions
It is currently possible to write multiple "start" commands into
git-update-ref(1) for a single session, but none of them except for the
first one actually have any effect.

Using such nested "start"s may eventually have a sensible effect. One
may imagine that it restarts the current transaction, effectively
emptying it and creating a new one. It may also allow for creation of
nested transactions. But currently, none of these are implemented.

Silently ignoring this misuse is making it hard to iterate in the future
if "start" is ever going to have meaningful semantics in such a context.
This commit thus makes sure to error out in case we see such use.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-16 13:44:01 -08:00
Patrick Steinhardt
262a4d28fe update-ref: allow creation of multiple transactions
While git-update-ref has recently grown commands which allow interactive
control of transactions in e48cf33b61 (update-ref: implement interactive
transaction handling, 2020-04-02), it is not yet possible to create
multiple transactions in a single session. To do so, one currently still
needs to invoke the executable multiple times.

This commit addresses this shortcoming by allowing the "start" command
to create a new transaction if the current transaction has already been
either committed or aborted.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-16 13:44:01 -08:00
Jeff King
a9bc372ef8 use size_t to store pack .idx byte offsets
We sometimes store the offset into a pack .idx file as an "unsigned
long", but the mmap'd size of a pack .idx file can exceed 4GB. This is
sufficient on LP64 systems like Linux, but will be too small on LLP64
systems like Windows, where "unsigned long" is still only 32 bits. Let's
use size_t, which is a better type for an offset into a memory buffer.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-16 13:41:35 -08:00
Jeff King
f86f769550 compute pack .idx byte offsets using size_t
A pack and its matching .idx file are limited to 2^32 objects, because
the pack format contains a 32-bit field to store the number of objects.
Hence we use uint32_t in the code.

But the byte count of even a .idx file can be much larger than that,
because it stores at least a hash and an offset for each object. So
using SHA-1, a v2 .idx file will cross the 4GB boundary at 153,391,650
objects. This confuses load_idx(), which computes the minimum size like
this:

  unsigned long min_size = 8 + 4*256 + nr*(hashsz + 4 + 4) + hashsz + hashsz;

Even though min_size will be big enough on most 64-bit platforms, the
actual arithmetic is done as a uint32_t, resulting in a truncation. We
actually exceed that min_size, but then we do:

  unsigned long max_size = min_size;
  if (nr)
          max_size += (nr - 1)*8;

to account for the variable-sized table. That computation doesn't
overflow quite so low, but with the truncation for min_size, we end up
with a max_size that is much smaller than our actual size. So we
complain that the idx is invalid, and can't find any of its objects.

We can fix this case by casting "nr" to a size_t, which will do the
multiplication in 64-bits (assuming you're on a 64-bit platform; this
will never work on a 32-bit system since we couldn't map the whole .idx
anyway). Likewise, we don't have to worry about further additions,
because adding a smaller number to a size_t will convert the other side
to a size_t.

A few notes:

  - obviously we could just declare "nr" as a size_t in the first place
    (and likewise, packed_git.num_objects).  But it's conceptually a
    uint32_t because of the on-disk format, and we correctly treat it
    that way in other contexts that don't need to compute byte offsets
    (e.g., iterating over the set of objects should and generally does
    use a uint32_t). Switching to size_t would make all of those other
    cases look wrong.

  - it could be argued that the proper type is off_t to represent the
    file offset. But in practice the .idx file must fit within memory,
    because we mmap the whole thing. And the rest of the code (including
    the idx_size variable we're comparing against) uses size_t.

  - we'll add the same cast to the max_size arithmetic line. Even though
    we're adding to a larger type, which will convert our result, the
    multiplication is still done as a 32-bit value and can itself
    overflow. I didn't check this with my test case, since it would need
    an even larger pack (~530M objects), but looking at compiler output
    shows that it works this way. The standard should agree, but I
    couldn't find anything explicit in 6.3.1.8 ("usual arithmetic
    conversions").

The case in load_idx() was the most immediate one that I was able to
trigger. After fixing it, looking up actual objects (including the very
last one in sha1 order) works in a test repo with 153,725,110 objects.
That's because bsearch_hash() works with uint32_t entry indices, and the
actual byte access:

  int cmp = hashcmp(table + mi * stride, sha1);

is done with "stride" as a size_t, causing the uint32_t "mi" to be
promoted to a size_t. This is the way most code will access the index
data.

However, I audited all of the other byte-wise accesses of
packed_git.index_data, and many of the others are suspect (they are
similar to the max_size one, where we are adding to a properly sized
offset or directly to a pointer, but the multiplication in the
sub-expression can overflow). I didn't trigger any of these in practice,
but I believe they're potential problems, and certainly adding in the
cast is not going to hurt anything here.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-16 13:41:35 -08:00
Josh Steadmon
a2a066d96a receive-pack: log received client session ID
When receive-pack receives a session-id capability from the client, log
the received session ID via a trace2 data event.

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 18:26:53 -08:00
Josh Steadmon
8073d75bbf receive-pack: advertise session ID in v0 capabilities
When transfer.advertiseSID is true, advertise receive-pack's session ID
via the new session-id capability.

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 18:26:53 -08:00
Junio C Hamano
902f358555 Merge branch 'rs/clear-commit-marks-in-repo'
Code clean-up.

* rs/clear-commit-marks-in-repo:
  bisect: clear flags in passed repository
  object: allow clear_commit_marks_all to handle any repo
2020-11-11 13:18:37 -08:00
Elijah Newren
449a900969 shortlog: use strset from strmap.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 12:55:27 -08:00
Elijah Newren
b19315d8ab Use new HASHMAP_INIT macro to simplify hashmap initialization
Now that hashamp has lazy initialization and a HASHMAP_INIT macro,
hashmaps allocated on the stack can be initialized without a call to
hashmap_init() and in some cases makes the code a bit shorter.  Convert
some callsites over to take advantage of this.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 12:55:27 -08:00
Jiang Xin
80ffeb94f4 receive-pack: use default version 0 for proc-receive
In the verison negotiation phase between "receive-pack" and
"proc-receive", "proc-receive" can send an empty flush-pkt to end the
negotiation and use default version 0. Capabilities (such as
"push-options") are not supported in version 0.

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 12:46:56 -08:00
Jiang Xin
f65003b4c4 receive-pack: gently write messages to proc-receive
Johannes found a flaky hang in `t5411/test-0013-bad-protocol.sh` in the
osx-clang job of the CI/PR builds, and ran into an issue when using
the `--stress` option with the following error messages:

    fatal: unable to write flush packet: Broken pipe
    send-pack: unexpected disconnect while reading sideband packet
    fatal: the remote end hung up unexpectedly

In this test case, the "proc-receive" hook sends an error message and
dies earlier. While "receive-pack" on the other side of the pipe
should forward the error message of the "proc-receive" hook to the
client side, but it fails to do so. This is because "receive-pack"
uses `packet_write_fmt()` and `packet_flush()` to write pkt-line
message to "proc-receive" hook, and these functions die immediately
when pipe is broken. Using "gently" forms for these functions will get
more predicable output.

Add more "--die-*" options to test helper to test different stages of
the protocol between "receive-pack" and "proc-receive" hook.

Reported-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 12:46:56 -08:00
Jeff King
3a1f91cfd9 rev-parse: handle --end-of-options
We taught rev-list a new way to separate options from revisions in
19e8789b23 (revision: allow --end-of-options to end option parsing,
2019-08-06), but rev-parse uses its own parser. It should know about
--end-of-options not only for consistency, but because it may be
presented with similarly ambiguous cases. E.g., if a caller does:

  git rev-parse "$rev" -- "$path"

to parse an untrusted input, then it will get confused if $rev contains
an option-like string like "--local-env-vars". Or even "--not-real",
which we'd keep as an option to pass along to rev-list.

Or even more importantly:

  git rev-parse --verify "$rev"

can be confused by options, even though its purpose is safely parsing
untrusted input. On the plus side, it will always fail the --verify
part, as it will not have parsed a revision, so the caller will
generally "fail closed" rather than continue to use the untrusted
string. But it will still trigger whatever option was in "$rev"; this
should be mostly harmless, since rev-parse options are all read-only,
but I didn't carefully audit all paths.

This patch lets callers write:

  git rev-parse --end-of-options "$rev" -- "$path"

and:

  git rev-parse --verify --end-of-options "$rev"

which will both treat "$rev" always as a revision parameter. The latter
is a bit clunky. It would be nicer if we had defined "--verify" to
require that its next argument be the revision. But we have not
historically done so, and:

  git rev-parse --verify -q "$rev"

does currently work. I added a test here to confirm that we didn't break
that.

A few implementation notes:

 - We don't document --end-of-options explicitly in commands, but rather
   in gitcli(7). So I didn't give it its own section in git-rev-parse(1).
   But I did call it out specifically in the --verify section, and
   include it in the examples, which should show best practices.

 - We don't have to re-indent the main option-parsing block, because we
   can combine our "did we see end of options" check with "does it start
   with a dash". The exception is the pre-setup options, which need
   their own block.

 - We do however have to pull the "--" parsing out of the "does it start
   with dash" block, because we want to parse it even if we've seen
   --end-of-options.

 - We'll leave "--end-of-options" in the output. This is probably not
   technically necessary, as a careful caller will do:

     git rev-parse --end-of-options $revs -- $paths

   and anything in $revs will be resolved to an object id. However, it
   does help a slightly less careful caller like:

     git rev-parse --end-of-options $revs_or_paths

   where a path "--foo" will remain in the output as long as it also
   exists on disk. In that case, it's helpful to retain --end-of-options
   to get passed along to rev-list, s it would otherwise see just
   "--foo".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-10 13:46:27 -08:00
Jeff King
9033addfa6 rev-parse: put all options under the "-" check
The option-parsing loop of rev-parse checks whether the first character
of an arg is "-". If so, then it enters a series of conditionals
checking for individual options. But some options are inexplicably
outside of that outer conditional.

This doesn't produce the wrong behavior; the conditional is actually
redundant with the individual option checks, and it's really only its
fallback "continue" that we care about. But we should at least be
consistent.

One obvious alternative is that we could get rid of the conditional
entirely. But we'll be using the extra block it provides in the next
patch.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-10 13:46:27 -08:00
Jeff King
e05e2ae8fe rev-parse: don't accept options after dashdash
Because of the order in which we check options in rev-parse, there are a
few options we accept even after a "--". This is wrong, because the
whole point of "--" is to say "everything after here is a path". Let's
move the "did we see a dashdash" check (it's called "as_is" in the code)
to the top of the parsing loop.

Note there is one subtlety here. The options are ordered so that some
are checked before we even see if we're in a repository (they continue
the loop, and if we get past a certain point, then we do the repository
setup). By moving the as_is check higher, it's also in that "before
setup" section, even though it might look at the repository via
verify_filename(). However, this works out: we'd never set as_is until
we parse "--", and we don't parse that until after doing the setup.

An alternative here to avoid the subtlety is to put the as_is check at
the top of the post-setup options. But then every pre-setup option would
have to remember to check "if (!as_is && !strcmp(...))". So while this
is a bit magical, it's harder for future code to get wrong.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-10 13:46:27 -08:00
Junio C Hamano
3baf58bfb4 format-patch: make output filename configurable
For the past 15 years, we've used the hardcoded 64 as the length
limit of the filename of the output from the "git format-patch"
command.  Since the value is shorter than the 80-column terminal, it
could grow without line wrapping a bit.  At the same time, since the
value is longer than half of the 80-column terminal, we could fit
two or more of them in "ls" output on such a terminal if we allowed
to lower it.

Introduce a new command line option --filename-max-length=<n> and a
new configuration variable format.filenameMaxLength to override the
hardcoded default.

While we are at it, remove a check that the name of output directory
does not exceed PATH_MAX---this check is pointless in that by the
time control reaches the function, the caller would already have
done an equivalent of "mkdir -p", so if the system does not like an
overly long directory name, the control wouldn't have reached here,
and otherwise, we know that the system allowed the output directory
to exist.  In the worst case, we will get an error when we try to
open the output file and handle the error correctly anyway.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-09 17:44:41 -08:00
Junio C Hamano
6a44c9c0d0 Merge branch 'jk/committer-date-is-author-date-fix-simplify'
Code simplification.

* jk/committer-date-is-author-date-fix-simplify:
  am, sequencer: stop parsing our own committer ident
2020-11-09 14:06:28 -08:00
Junio C Hamano
ecf95d938b Merge branch 'ab/git-remote-exit-code'
Exit codes from "git remote add" etc. were not usable by scripted
callers.

* ab/git-remote-exit-code:
  remote: add meaningful exit code on missing/existing
2020-11-09 14:06:26 -08:00
Junio C Hamano
92d6bd2e90 Merge branch 'jk/checkout-index-errors'
"git checkout-index" did not consistently signal an error with its
exit status.

* jk/checkout-index-errors:
  checkout-index: propagate errors to exit code
  checkout-index: drop error message from empty --stage=all
2020-11-09 14:06:26 -08:00
Junio C Hamano
cfdc70b299 Merge branch 'mr/bisect-in-c-3'
Rewriting "git bisect" in C continues.

* mr/bisect-in-c-3:
  bisect--helper: retire `--bisect-autostart` subcommand
  bisect--helper: retire `--write-terms` subcommand
  bisect--helper: retire `--check-expected-revs` subcommand
  bisect--helper: reimplement `bisect_state` & `bisect_head` shell functions in C
  bisect--helper: retire `--next-all` subcommand
  bisect--helper: retire `--bisect-clean-state` subcommand
  bisect--helper: finish porting `bisect_start()` to C
2020-11-09 14:06:25 -08:00
Phillip Wood
8843302307 rebase -i: simplify get_revision_ranges()
Now that all the external users of head_hash have been converted to
use a opts->orig_head instead we can stop returning head_hash from
get_revision_ranges().

Because we want to pass the full object names back to the caller in
`revisions` the find_unique_abbrev_r() call that was used to initialize
`head_hash` is replaced with oid_to_hex().

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-04 14:10:41 -08:00
Phillip Wood
a2bb10d06d rebase -i: use struct object_id when writing state
Rather than passing a string around pass the struct object_id that the
string was created from call oid_hex() when we write the file.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-04 14:10:41 -08:00
Phillip Wood
f3e27a02d5 rebase -i: use struct object_id rather than looking up commit
We already have a struct object_id containing the oid that we want to
set ORIG_HEAD to so use that rather than converting it to a string and
then calling get_oid() on that string.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-04 14:10:41 -08:00
Phillip Wood
e100bea481 rebase -i: stop overwriting ORIG_HEAD buffer
After rebasing, ORIG_HEAD is supposed to point to the old HEAD of the
rebased branch.  The code used find_unique_abbrev() to obtain the
object name of the old HEAD and wrote to both
.git/rebase-merge/orig-head (used by `rebase --abort` to go back to
the previous state) and to ORIG_HEAD.  The buffer find_unique_abbrev()
gives back is volatile, unfortunately, and was overwritten after the
former file is written but before ORIG_FILE is written, leaving an
incorrect object name in it.

Avoid relying on the volatile buffer of find_unique_abbrev(), and
instead supply our own buffer to keep the object name.

I think that all of the users of head_hash should actually be using
opts->orig_head instead as passing a string rather than a struct
object_id around is a hang over from the scripted implementation. This
patch just fixes the immediate bug and adds a regression test based on
Caspar's reproduction example[1]. The users will be converted to use
struct object_id and head_hash removed in the next few commits.

[1] https://lore.kernel.org/git/CAFzd1+7PDg2PZgKw7U0kdepdYuoML9wSN4kofmB_-8NHrbbrHg@mail.gmail.com

Reported-by: Caspar Duregger <herr.kaste@gmail.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-04 14:10:41 -08:00
Jeff King
dc1672dd10 format-patch: support --output option
We've never intended to support diff's --output option in format-patch.
And until baa4adc66a (parse-options: disable option abbreviation with
PARSE_OPT_KEEP_UNKNOWN, 2019-01-27), it was impossible to trigger. We
first parse the format-patch options before handing the remainder off to
setup_revisions(). Before that commit, we'd accept "--output=foo" as an
abbreviation for "--output-directory=foo". But afterwards, we don't
check abbreviations, and --output gets passed to the diff code.

This results in nonsense behavior and bugs. The diff code will have
opened a filehandle at rev.diffopt.file, but we'll overwrite that with
our own handles that we open for each individual patch file. So the
--output file will always just be empty. But worse, the diff code also
sets rev.diffopt.close_file, so log_tree_commit() will close the
filehandle itself. And then the main loop in cmd_format_patch() will try
to close it again, resulting in a double-free.

The simplest solution would be to just disallow --output with
format-patch, as nobody ever intended it to work. However, we have
accidentally documented it (because format-patch includes diff-options).
And it does work with "git log", which writes the whole output to the
specified file. It's easy enough to make that work for format-patch,
too: it's really the same as --stdout, but pointed at a specific file.

We can detect the use of the --output option by the "close_file" flag
(note that we can't use rev.diffopt.file, since the diff setup will
otherwise set it to stdout). So we just need to unset that flag, but
don't have to do anything else. Our situation is otherwise exactly like
--stdout (note that we don't fclose() the file, but nor does the stdout
case; exiting the program takes care of that for us).

Reported-by: Johannes Postler <johannes.postler@txture.io>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-04 14:05:29 -08:00