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96 commits

Author SHA1 Message Date
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
07601b5b36 Merge branch 'ma/worktree-cleanups'
Code clean-up.

* ma/worktree-cleanups:
  worktree: use skip_prefix to parse target
  worktree: rename copy-pasted variable
  worktree: update renamed variable in comment
  worktree: inline `worktree_ref()` into its only caller
  wt-status: introduce wt_status_state_free_buffers()
  wt-status: print to s->fp, not stdout
  wt-status: replace sha1 mentions with oid
2020-10-05 14:01:52 -07:00
Martin Ågren
a46d1f7321 worktree: use skip_prefix to parse target
Instead of checking for "refs/heads/" using `starts_with()`, then
skipping past "refs/heads/" using `strlen()`, just use `skip_prefix()`.

In `is_worktree_being_rebased()`, we can adjust the indentation while
we're here and lose a pair of parentheses which isn't needed and which
might even make the reader wonder what they're missing and why that
grouping is there.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-27 14:21:47 -07:00
Martin Ågren
fb07bd4297 worktree: rename copy-pasted variable
As the commit message of 04a3dfb8b5 ("worktree.c: check whether branch
is bisected in another worktree", 2016-04-22) indicates, the function
`is_worktree_being_bisected()` is based on the older function
`is_worktree_being_rebased()`. This heritage can also be seen in the
name of the variable where we store our return value: It was never
adapted while copy-editing and remains as `found_rebase`.

Rename the variable to make clear that we're looking for a bisect(ion),
nothing else.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-27 14:21:47 -07:00
Martin Ågren
cfaf9f05c6 worktree: update renamed variable in comment
The comment above `add_head_info()` mentions "head_sha1", but it was
renamed to "head_oid" in 0f05154c70 ("worktree: convert struct worktree
to object_id", 2017-10-15). Update the comment.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-27 14:21:47 -07:00
Martin Ågren
ef2d5547fa worktree: inline worktree_ref() into its only caller
We have `strbuf_worktree_ref()`, which works on a strbuf, and a wrapper
for it, `worktree_ref()` which returns a string. We even make this
wrapper available through worktree.h. But it only has a single caller,
sitting right next to it in worktree.c.

Just inline the wrapper into its only caller. This means the caller can
quite naturally reuse a single strbuf. We currently achieve something
similar by having a static strbuf in the wrapper.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-27 14:21:47 -07:00
Martin Ågren
962dd7ebc3 wt-status: introduce wt_status_state_free_buffers()
When we have a `struct wt_status_state`, we manually free its `branch`,
`onto` and `detached_from`, or sometimes just one or two of them.
Provide a function `wt_status_state_free_buffers()` which does the
freeing.

The callers are still aware of these fields, e.g., they check whether
`branch` was populated or not. But this way, they don't need to know
about *all* of them, and if `struct wt_status_state` gets more fields,
they will not need to learn to free them.

Users of `struct wt_status` (which contains a `wt_status_state`) already
have `wt_status_collect_free_buffers()` (corresponding to
`wt_status_collect()`) which we can also teach to use this new helper.

Finally, note that we're currently leaving dangling pointers behind.
Some callers work on a stack-allocated struct, where this is obviously
ok. But for the users of `run_status()` in builtin/commit.c, there are
ample opportunities for someone to mistakenly use those dangling
pointers. We seem to be ok for now, but it's a use-after-free waiting to
happen. Let's leave NULL-pointers behind instead.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-27 14:21:47 -07:00
Eric Sunshine
b214ab5aa5 worktree: teach "repair" to fix outgoing links to worktrees
The .git/worktrees/<id>/gitdir file points at the location of a linked
worktree's .git file. Its content must be of the form
/path/to/worktree/.git (from which the location of the worktree itself
can be derived by stripping the "/.git" suffix). If the gitdir file is
deleted or becomes corrupted or outdated, then Git will be unable to
find the linked worktree. An easy way for the gitdir file to become
outdated is for the user to move the worktree manually (without using
"git worktree move"). Although it is possible to manually update the
gitdir file to reflect the new linked worktree location, doing so
requires a level of knowledge about worktree internals beyond what a
user should be expected to know offhand.

Therefore, teach "git worktree repair" how to repair broken or outdated
.git/worktrees/<id>/gitdir files automatically. (For this to work, the
command must either be invoked from within the worktree whose gitdir
file requires repair, or from within the main or any linked worktree by
providing the path of the broken worktree as an argument to "git
worktree repair".)

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-31 11:47:45 -07:00
Eric Sunshine
bdd1f3e4da worktree: teach "repair" to fix worktree back-links to main worktree
The .git file in a linked worktree is a "gitfile" which points back to
the .git/worktrees/<id> entry in the main worktree or bare repository.
If a worktree's .git file is deleted or becomes corrupted or outdated,
then the linked worktree won't know how to find the repository or any of
its own administrative files (such as 'index', 'HEAD', etc.). An easy
way for the .git file to become outdated is for the user to move the
main worktree or bare repository. Although it is possible to manually
update each linked worktree's .git file to reflect the new repository
location, doing so requires a level of knowledge about worktree
internals beyond what a user should be expected to know offhand.

Therefore, teach "git worktree repair" how to repair broken or outdated
worktree .git files automatically. (For this to work, the command must
be invoked from within the main worktree or bare repository, or from
within a worktree which has not become disconnected from the repository
-- such as one which was created after the repository was moved.)

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-31 11:47:45 -07:00
Eric Sunshine
918d8ff780 worktree: retire special-case normalization of main worktree path
In order for "git-worktree list" to present consistent results,
get_main_worktree() performs manual normalization on the repository
path (returned by get_common_dir()) after passing it through
strbuf_add_absolute_path(). In particular, it cleans up the path for
three distinct cases when the current working directory is (1) the main
worktree, (2) the .git/ subdirectory, or (3) a bare repository.

The need for such special-cases is a direct consequence of employing
strbuf_add_absolute_path() which, for the sake of efficiency, doesn't
bother normalizing the path (such as folding out redundant path
components) after making it absolute. Lack of normalization is not
typically a problem since redundant path elements make no difference
when working with paths at the filesystem level. However, when preparing
paths for presentation, possible redundant path components make it
difficult to ensure consistency.

Eliminate the need for these special cases by instead making the path
absolute via strbuf_add_real_path() which normalizes the path for us.
Once normalized, the only case we need to handle manually is converting
it to the path of the main worktree by stripping the "/.git" suffix.
This stripping of the "/.git" suffix is a regular idiom in
worktree-related code; for instance, it is employed by
get_linked_worktree(), as well.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-31 19:56:11 -07:00
Eric Sunshine
1c4854ec73 worktree: drop bogus and unnecessary path munging
The content of .git/worktrees/<id>/gitdir must be a path of the form
"/path/to/worktree/.git". Any other content would be indicative of a
corrupt "gitdir" file. To determine the path of the worktree itself one
merely strips the "/.git" suffix, and this is indeed how the worktree
path was determined from inception.

However, 5193490442 (worktree: add a function to get worktree details,
2015-10-08) extended the path manipulation in a mysterious way. If it is
unable to strip "/.git" from the path, then it instead reports the
current working directory as the linked worktree's path:

    if (!strbuf_strip_suffix(&worktree_path, "/.git")) {
        strbuf_reset(&worktree_path);
        strbuf_add_absolute_path(&worktree_path, ".");
        strbuf_strip_suffix(&worktree_path, "/.");
    }

This logic is clearly bogus; it can never be generally correct behavior.
It materialized out of thin air in 5193490442 with neither explanation
nor tests to illustrate a case in which it would be desirable.

It's possible that this logic was introduced to somehow deal with a
corrupt "gitdir" file, so that it returns _some_ sort of meaningful
value, but returning the current working directory is not helpful. In
fact, it is quite misleading (except in the one specific case when the
current directory is the worktree whose "gitdir" entry is corrupt).
Moreover, reporting the corrupt value to the user, rather than fibbing
about it and hiding it outright, is more helpful since it may aid in
diagnosing the problem.

Therefore, drop this bogus path munging and restore the logic to the
original behavior of merely stripping "/.git".

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-31 19:56:11 -07:00
Eric Sunshine
246756f775 worktree: drop unused code from get_linked_worktree()
This code has been unused since fa099d2322 (worktree.c: kill parse_ref()
in favor of refs_resolve_ref_unsafe(), 2017-04-24), so drop it.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-31 19:56:11 -07:00
Eric Sunshine
62573a57f0 worktree: drop pointless strbuf_release()
The content of this strbuf is unconditionally detached several lines
before the strbuf_release() and the strbuf is never touched again after
that point.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-31 19:56:10 -07:00
Junio C Hamano
43f46d6da5 Merge branch 'es/worktree-code-cleanup'
Code cleanup.

* es/worktree-code-cleanup:
  worktree: avoid dead-code in conditional
2020-07-06 22:09:19 -07:00
Junio C Hamano
645f63111b Merge branch 'es/get-worktrees-unsort'
API cleanup for get_worktrees()

* es/get-worktrees-unsort:
  worktree: drop get_worktrees() unused 'flags' argument
  worktree: drop get_worktrees() special-purpose sorting option
2020-07-06 22:09:15 -07:00
Eric Sunshine
5f4ee57ad9 worktree: avoid dead-code in conditional
get_worktrees() retrieves a list of all worktrees associated with a
repository, including the main worktree. The location of the main
worktree is determined by get_main_worktree() which needs to handle
three distinct cases for the main worktree after absolute-path
conversion:

    * <bare-repository>/.
    * <main-worktree>/.git/. (when $CWD is .git)
    * <main-worktree>/.git (when $CWD is any worktree)

They all need to be normalized to just the <path> portion, dropping any
"/." or "/.git" suffix.

It turns out, however, that get_main_worktree() was only handling the
first and last cases, i.e.:

    if (!strip_suffix(path, "/.git"))
        strip_suffix(path, "/.");

This shortcoming was addressed by 45f274fbb1 (get_main_worktree(): allow
it to be called in the Git directory, 2020-02-23) by changing the logic
to:

    strip_suffix(path, "/.");
    if (!strip_suffix(path, "/.git"))
        strip_suffix(path, "/.");

which makes the final strip_suffix() invocation dead-code.

Fix this oversight by enumerating the three distinct cases explicitly
rather than attempting to strip the suffix(es) incrementally.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-24 17:39:28 -07:00
Eric Sunshine
03f2465bb1 worktree: drop get_worktrees() unused 'flags' argument
get_worktrees() accepts a 'flags' argument, however, there are no
existing flags (the lone flag GWT_SORT_LINKED was recently retired) and
no behavior which can be tweaked. Therefore, drop the 'flags' argument.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-22 10:31:15 -07:00
Eric Sunshine
d9c54c2bbf worktree: drop get_worktrees() special-purpose sorting option
Of all the clients of get_worktrees(), only "git worktree list" wants
the list sorted in a very specific way; other clients simply don't care
about the order. Rather than imbuing get_worktrees() with special
knowledge about how various clients -- now and in the future -- may want
the list sorted, drop the sorting capability altogether and make it the
client's responsibility to sort the list if needed.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-22 10:30:29 -07:00
Junio C Hamano
f8cb64e3d4 Merge branch 'bc/sha-256-part-1-of-4'
SHA-256 transition continues.

* bc/sha-256-part-1-of-4: (22 commits)
  fast-import: add options for rewriting submodules
  fast-import: add a generic function to iterate over marks
  fast-import: make find_marks work on any mark set
  fast-import: add helper function for inserting mark object entries
  fast-import: permit reading multiple marks files
  commit: use expected signature header for SHA-256
  worktree: allow repository version 1
  init-db: move writing repo version into a function
  builtin/init-db: add environment variable for new repo hash
  builtin/init-db: allow specifying hash algorithm on command line
  setup: allow check_repository_format to read repository format
  t/helper: make repository tests hash independent
  t/helper: initialize repository if necessary
  t/helper/test-dump-split-index: initialize git repository
  t6300: make hash algorithm independent
  t6300: abstract away SHA-1-specific constants
  t: use hash-specific lookup tables to define test constants
  repository: require a build flag to use SHA-256
  hex: add functions to parse hex object IDs in any algorithm
  hex: introduce parsing variants taking hash algorithms
  ...
2020-03-26 17:11:20 -07:00
Alexandr Miloslavskiy
4530a85b4c real_path_if_valid(): remove unsafe API
This commit continues the work started with previous commit.

Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-10 11:41:40 -07:00
Alexandr Miloslavskiy
3d7747e318 real_path: remove unsafe API
Returning a shared buffer invites very subtle bugs due to reentrancy or
multi-threading, as demonstrated by the previous patch.

There was an unfinished effort to abolish this [1].

Let's finally rid of `real_path()`, using `strbuf_realpath()` instead.

This patch uses a local `strbuf` for most places where `real_path()` was
previously called.

However, two places return the value of `real_path()` to the caller. For
them, a `static` local `strbuf` was added, effectively pushing the
problem one level higher:
    read_gitfile_gently()
    get_superproject_working_tree()

[1] https://lore.kernel.org/git/1480964316-99305-1-git-send-email-bmwill@google.com/

Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-10 11:41:40 -07:00
Junio C Hamano
4a2e91db65 Merge branch 'hv/receive-denycurrent-everywhere'
"git push" should stop from updating a branch that is checked out
when receive.denyCurrentBranch configuration is set, but it failed
to pay attention to checkouts in secondary worktrees.  This has
been corrected.

* hv/receive-denycurrent-everywhere:
  t2402: test worktree path when called in .git directory
  receive.denyCurrentBranch: respect all worktrees
  t5509: use a bare repository for test push target
  get_main_worktree(): allow it to be called in the Git directory
2020-03-05 10:43:03 -08:00
Junio C Hamano
49e5043b09 Merge branch 'es/worktree-avoid-duplication-fix'
In rare cases "git worktree add <path>" could think that <path>
was already a registered worktree even when it wasn't and refuse
to add the new worktree. This has been corrected.

* es/worktree-avoid-duplication-fix:
  worktree: don't allow "add" validation to be fooled by suffix matching
  worktree: add utility to find worktree by pathname
  worktree: improve find_worktree() documentation
2020-03-05 10:43:02 -08:00
Eric Sunshine
bb4995fc3f worktree: add utility to find worktree by pathname
find_worktree() employs heuristics to match user provided input -- which
may be a pathname or some sort of shorthand -- with an actual worktree.
Although this convenience allows a user to identify a worktree with
minimal typing, the black-box nature of these heuristics makes it
potentially difficult for callers which already know the exact path of a
worktree to be confident that the correct worktree will be returned for
any specific pathname (particularly a relative one), especially as the
heuristics are enhanced and updated.

Therefore, add a companion function, find_worktree_by_path(), which
deterministically identifies a worktree strictly by pathname with no
interpretation and no magic matching.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 13:04:30 -08:00
Eric Sunshine
02bbbe9df9 worktree: drop unused code from get_main_worktree()
This code has been unused since fa099d2322 (worktree.c: kill parse_ref()
in favor of refs_resolve_ref_unsafe(), 2017-04-24), so drop it.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 12:20:45 -08:00
Hariom Verma
45f274fbb1 get_main_worktree(): allow it to be called in the Git directory
When called in the Git directory of a non-bare repository, this function
would not return the directory of the main worktree, but of the Git
directory instead.

The reason: when the Git directory is the current working directory, the
absolute path of the common directory will be reported with a trailing
`/.git/.`, which the code of `get_main_worktree()` does not handle
correctly.

Let's fix this.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 11:13:44 -08:00
brian m. carlson
e02a7141f8 worktree: allow repository version 1
Git supports both repository versions 0 and 1.  These formats are
identical except for the presence of extensions.  When using an
extension, such as for a different hash algorithm, a check for only
version 0 causes the check to fail.  Instead, call
verify_repository_format to verify that we have an appropriate version
and no unknown extensions.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 09:33:30 -08:00
Junio C Hamano
000bce0ee4 Merge branch 'nd/corrupt-worktrees'
"git worktree add" used to fail when another worktree connected to
the same repository was corrupt, which has been corrected.

* nd/corrupt-worktrees:
  worktree add: be tolerant of corrupt worktrees
2019-06-13 13:19:41 -07:00
Nguyễn Thái Ngọc Duy
105df73e71 worktree add: be tolerant of corrupt worktrees
find_worktree() can die() unexpectedly because it uses real_path()
instead of the gentler version. When it's used in 'git worktree add' [1]
and there's a bad worktree, this die() could prevent people from adding
new worktrees.

The "bad" condition to trigger this is when a parent of the worktree's
location is deleted. Then real_path() will complain.

Use the other version so that bad worktrees won't affect 'worktree
add'. The bad ones will eventually be pruned, we just have to tolerate
them for a bit.

[1] added in cb56f55c16 (worktree: disallow adding same path multiple
    times, 2018-08-28), or since v2.20.0. Though the real bug in
    find_worktree() is much older.

Reported-by: Shaheed Haque <shaheedhaque@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-15 14:17:18 +09:00
Junio C Hamano
ec2642a2a1 Merge branch 'jt/submodule-repo-is-with-worktree'
The logic to tell if a Git repository has a working tree protects
"git branch -D" from removing the branch that is currently checked
out by mistake.  The implementation of this logic was broken for
repositories with unusual name, which unfortunately is the norm for
submodules these days.  This has been fixed.

* jt/submodule-repo-is-with-worktree:
  worktree: update is_bare heuristics
2019-05-09 00:37:28 +09:00
Jonathan Tan
f3534c98e4 worktree: update is_bare heuristics
When "git branch -D <name>" is run, Git usually first checks if that
branch is currently checked out. But this check is not performed if the
Git directory of that repository is not at "<repo>/.git", which is the
case if that repository is a submodule that has its Git directory stored
as "super/.git/modules/<repo>", for example. This results in the branch
being deleted even though it is checked out.

This is because get_main_worktree() in worktree.c sets is_bare on a
worktree only using the heuristic that a repo is bare if the worktree's
path does not end in "/.git", and not bare otherwise. This is_bare code
was introduced in 92718b7438 ("worktree: add details to the worktree
struct", 2015-10-08), following a pre-core.bare heuristic. This patch
does 2 things:

 - Teach get_main_worktree() to use is_bare_repository() instead,
   introduced in 7d1864ce67 ("Introduce is_bare_repository() and
   core.bare configuration variable", 2007-01-07) and updated in
   e90fdc39b6 ("Clean up work-tree handling", 2007-08-01). This solves
   the "git branch -D <name>" problem described above. However...

 - If a repository has core.bare=1 but the "git" command is being run
   from one of its secondary worktrees, is_bare_repository() returns
   false (which is fine, since there is a worktree available). However,
   treating the main worktree as non-bare when it is bare causes issues:
   for example, failure to delete a branch from a secondary worktree
   that is referred to by a main worktree's HEAD, even if that main
   worktree is bare.

   In order to avoid that, also check core.bare when setting is_bare. If
   core.bare=1, trust it, and otherwise, use is_bare_repository().

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-21 13:58:55 +09:00
Martin Ågren
e8805af1c3 setup: fix memory leaks with struct repository_format
After we set up a `struct repository_format`, it owns various pieces of
allocated memory. We then either use those members, because we decide we
want to use the "candidate" repository format, or we discard the
candidate / scratch space. In the first case, we transfer ownership of
the memory to a few global variables. In the latter case, we just
silently drop the struct and end up leaking memory.

Introduce an initialization macro `REPOSITORY_FORMAT_INIT` and a
function `clear_repository_format()`, to be used on each side of
`read_repository_format()`. To have a clear and simple memory ownership,
let all users of `struct repository_format` duplicate the strings that
they take from it, rather than stealing the pointers.

Call `clear_...()` at the start of `read_...()` instead of just zeroing
the struct, since we sometimes enter the function multiple times. Thus,
it is important to initialize the struct before calling `read_...()`, so
document that. It's also important because we might not even call
`read_...()` before we call `clear_...()`, see, e.g., builtin/init-db.c.

Teach `read_...()` to clear the struct on error, so that it is reset to
a safe state, and document this. (In `setup_git_directory_gently()`, we
look at `repo_fmt.hash_algo` even if `repo_fmt.version` is -1, which we
weren't actually supposed to do per the API. After this commit, that's
ok.)

We inherit the existing code's combining "error" and "no version found".
Both are signalled through `version == -1` and now both cause us to
clear any partial configuration we have picked up. For "extensions.*",
that's fine, since they require a positive version number. For
"core.bare" and "core.worktree", we're already verifying that we have a
non-negative version number before using them.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-01 08:52:00 +09:00
Junio C Hamano
e146cc97be Merge branch 'nd/per-worktree-ref-iteration'
The code to traverse objects for reachability, used to decide what
objects are unreferenced and expendable, have been taught to also
consider per-worktree refs of other worktrees as starting points to
prevent data loss.

* nd/per-worktree-ref-iteration:
  git-worktree.txt: correct linkgit command name
  reflog expire: cover reflog from all worktrees
  fsck: check HEAD and reflog from other worktrees
  fsck: move fsck_head_link() to get_default_heads() to avoid some globals
  revision.c: better error reporting on ref from different worktrees
  revision.c: correct a parameter name
  refs: new ref types to make per-worktree refs visible to all worktrees
  Add a place for (not) sharing stuff between worktrees
  refs.c: indent with tabs, not spaces
2018-11-13 22:37:26 +09:00
Nickolai Belakovski
d236f12bde worktree: rename is_worktree_locked to worktree_lock_reason
A function prefixed with 'is_' would be expected to return a boolean,
however this function returns a string.

Signed-off-by: Nickolai Belakovski <nbelakovski@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-31 11:41:47 +09:00
Nguyễn Thái Ngọc Duy
ab3e1f78ae revision.c: better error reporting on ref from different worktrees
Make use of the new ref aliases to pass refs from another worktree
around and access them from the current ref store instead. This does
not change any functionality, but when a problem arises, we would like
the reported messages to mention full ref aliases, like this:

    fatal: bad object worktrees/ztemp/HEAD
    warning: reflog of 'main-worktree/HEAD' references pruned commits

instead of

    fatal: bad object HEAD
    warning: reflog of 'HEAD' references pruned commits

which does not really tell where the refs are from.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-22 13:32:29 +09:00
Nguyễn Thái Ngọc Duy
3a3b9d8cde refs: new ref types to make per-worktree refs visible to all worktrees
One of the problems with multiple worktree is accessing per-worktree
refs of one worktree from another worktree. This was sort of solved by
multiple ref store, where the code can open the ref store of another
worktree and has access to the ref space of that worktree.

The problem with this is reporting. "HEAD" in another ref space is
also called "HEAD" like in the current ref space. In order to
differentiate them, all the code must somehow carry the ref store
around and print something like "HEAD from this ref store".

But that is not feasible (or possible with a _lot_ of work). With the
current design, we pass a reference around as a string (so called
"refname"). Extending this design to pass a string _and_ a ref store
is a nightmare, especially when handling extended SHA-1 syntax.

So we do it another way. Instead of entering a separate ref space, we
make refs from other worktrees available in the current ref space. So
"HEAD" is always HEAD of the current worktree, but then we can have
"worktrees/blah/HEAD" to denote HEAD from a worktree named
"blah". This syntax coincidentally matches the underlying directory
structure which makes implementation a bit easier.

The main worktree has to be treated specially because well... it's
special from the beginning. So HEAD from the main worktree is
acccessible via the name "main-worktree/HEAD" instead of
"worktrees/main/HEAD" because "main" could be just another secondary
worktree.

This patch also makes it possible to specify refs from one worktree in
another one, e.g.

    git log worktrees/foo/HEAD

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-22 13:32:29 +09:00
Eric Sunshine
4c5fa9e6c4 worktree: don't die() in library function find_worktree()
Callers don't expect library function find_worktree() to die(); they
expect it to return the named worktree if found, or NULL if not.
Although find_worktree() itself never invokes die(), it calls
real_pathdup() with 'die_on_error' incorrectly set to 'true', thus will
die() indirectly if the user-provided path is not to real_pathdup()'s
liking. This can be observed, for instance, with any git-worktree
command which searches for an existing worktree:

    $ git worktree unlock foo
    fatal: 'foo' is not a working tree
    $ git worktree unlock foo/bar
    fatal: Invalid path '.../foo': No such file or directory

The first error message is the expected one from "git worktree unlock"
not finding the specified worktree; the second is from find_worktree()
invoking real_pathdup() incorrectly and die()ing prematurely.

Aside from the inconsistent error message between the two cases, this
bug hasn't otherwise been a serious problem since existing callers all
die() anyhow when the worktree can't be found. However, that may not be
true of callers added in the future, so fix find_worktree() to avoid
die()ing.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-30 09:28:02 -07:00
Johannes Schindelin
033abf97fc Replace all die("BUG: ...") calls by BUG() ones
In d8193743e0 (usage.c: add BUG() function, 2017-05-12), a new macro
was introduced to use for reporting bugs instead of die(). It was then
subsequently used to convert one single caller in 588a538ae5
(setup_git_env: convert die("BUG") to BUG(), 2017-05-12).

The cover letter of the patch series containing this patch
(cf 20170513032414.mfrwabt4hovujde2@sigill.intra.peff.net) is not
terribly clear why only one call site was converted, or what the plan
is for other, similar calls to die() to report bugs.

Let's just convert all remaining ones in one fell swoop.

This trick was performed by this invocation:

	sed -i 's/die("BUG: /BUG("/g' $(git grep -l 'die("BUG' \*.c)

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-06 19:06:13 +09:00
Nguyễn Thái Ngọc Duy
ee6763af0a worktree remove: allow it when $GIT_WORK_TREE is already gone
"git worktree remove" basically consists of two things

- delete $GIT_WORK_TREE
- delete $GIT_DIR (which is $SUPER_GIT_DIR/worktrees/something)

If $GIT_WORK_TREE is already gone for some reason, we should be able
to finish the job by deleting $GIT_DIR.

Two notes:

- $GIT_WORK_TREE _can_ be missing if the worktree is locked. In that
  case we must not delete $GIT_DIR because the real $GIT_WORK_TREE may
  be in a usb stick somewhere. This is already handled because we
  check for lock first.

- validate_worktree() is still called because it may do more checks in
  future (and it already does something else, like checking main
  worktree, but that's irrelevant in this case)

Noticed-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-12 13:13:35 -08:00
Nguyễn Thái Ngọc Duy
9c620fc7a6 worktree.c: add update_worktree_location()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-12 13:13:35 -08:00
Nguyễn Thái Ngọc Duy
4ddddc1f1d worktree.c: add validate_worktree()
This function is later used by "worktree move" and "worktree remove"
to ensure that we have a good connection between the repository and
the worktree. For example, if a worktree is moved manually, the
worktree location recorded in $GIT_DIR/worktrees/.../gitdir is
incorrect and we should not move that one.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-24 11:04:26 -08:00
Junio C Hamano
e7e456f500 Merge branch 'bc/object-id'
Conversion from uchar[20] to struct object_id continues.

* bc/object-id: (25 commits)
  refs/files-backend: convert static functions to object_id
  refs: convert read_raw_ref backends to struct object_id
  refs: convert peel_object to struct object_id
  refs: convert resolve_ref_unsafe to struct object_id
  worktree: convert struct worktree to object_id
  refs: convert resolve_gitlink_ref to struct object_id
  Convert remaining callers of resolve_gitlink_ref to object_id
  sha1_file: convert index_path and index_fd to struct object_id
  refs: convert reflog_expire parameter to struct object_id
  refs: convert read_ref_at to struct object_id
  refs: convert peel_ref to struct object_id
  builtin/pack-objects: convert to struct object_id
  pack-bitmap: convert traverse_bitmap_commit_list to object_id
  refs: convert dwim_log to struct object_id
  builtin/reflog: convert remaining unsigned char uses to object_id
  refs: convert dwim_ref and expand_ref to struct object_id
  refs: convert read_ref and read_ref_full to object_id
  refs: convert resolve_refdup and refs_resolve_refdup to struct object_id
  Convert check_connected to use struct object_id
  refs: update ref transactions to use struct object_id
  ...
2017-11-06 14:24:27 +09:00
Jeff King
dbd2b55cb7 worktree: handle broken symrefs in find_shared_symref()
The refs_resolve_ref_unsafe() function may return NULL even
with a REF_ISSYMREF flag if a symref points to a broken ref.
As a result, it's possible for find_shared_symref() to
segfault when it passes NULL to strcmp().

This is hard to trigger for most code paths. We typically
pass HEAD to the function as the symref to resolve, and
programs like "git branch" will bail much earlier if HEAD
isn't valid.

I did manage to trigger it through one very obscure
sequence:

  # You have multiple notes refs which conflict.
  git notes add -m base
  git notes --ref refs/notes/foo add -m foo

  # There's left-over cruft in NOTES_MERGE_REF that
  # makes it a broken symref (in this case we point
  # to a syntactically invalid ref).
  echo "ref: refs/heads/master.lock" >.git/NOTES_MERGE_REF

  # You try to merge the notes. We read the broken value in
  # order to complain that another notes-merge is
  # in-progress, but we segfault in find_shared_symref().
  git notes merge refs/notes/foo

This is obviously silly and almost certainly impossible to
trigger accidentally, but it does show that the bug is
triggerable from at least one code path. In addition, it
would trigger if we saw a transient filesystem error when
resolving the pointed-to ref.

We can fix this by treating NULL the same as a non-matching
symref. Arguably we'd prefer to know if a symref points to
"refs/heads/foo", but "refs/heads/foo" is broken. But
refs_resolve_ref_unsafe() isn't capable of giving us that
information, so this is the best we can do.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-21 21:30:07 +09:00
brian m. carlson
49e61479be refs: convert resolve_ref_unsafe to struct object_id
Convert resolve_ref_unsafe to take a pointer to struct object_id by
converting one remaining caller to use struct object_id, removing the
temporary NULL pointer check in expand_ref, converting the declaration
and definition, and applying the following semantic patch:

@@
expression E1, E2, E3, E4;
@@
- resolve_ref_unsafe(E1, E2, E3.hash, E4)
+ resolve_ref_unsafe(E1, E2, &E3, E4)

@@
expression E1, E2, E3, E4;
@@
- resolve_ref_unsafe(E1, E2, E3->hash, E4)
+ resolve_ref_unsafe(E1, E2, E3, E4)

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16 11:05:51 +09:00
brian m. carlson
0f05154c70 worktree: convert struct worktree to object_id
Convert the head_sha1 member to be head_oid instead.  This is required
to convert resolve_ref_unsafe.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16 11:05:51 +09:00
René Scharfe
e691b027b6 refs: pass NULL to refs_resolve_ref_unsafe() if hash is not needed
This allows us to get rid of two write-only variables, one of them
being a SHA1 buffer.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-24 10:18:18 +09:00
Junio C Hamano
8a044c7f1d Merge branch 'nd/prune-in-worktree'
"git gc" and friends when multiple worktrees are used off of a
single repository did not consider the index and per-worktree refs
of other worktrees as the root for reachability traversal, making
objects that are in use only in other worktrees to be subject to
garbage collection.

* nd/prune-in-worktree:
  refs.c: reindent get_submodule_ref_store()
  refs.c: remove fallback-to-main-store code get_submodule_ref_store()
  rev-list: expose and document --single-worktree
  revision.c: --reflog add HEAD reflog from all worktrees
  files-backend: make reflog iterator go through per-worktree reflog
  revision.c: --all adds HEAD from all worktrees
  refs: remove dead for_each_*_submodule()
  refs.c: move for_each_remote_ref_submodule() to submodule.c
  revision.c: use refs_for_each*() instead of for_each_*_submodule()
  refs: add refs_head_ref()
  refs: move submodule slash stripping code to get_submodule_ref_store
  refs.c: refactor get_submodule_ref_store(), share common free block
  revision.c: --indexed-objects add objects from all worktrees
  revision.c: refactor add_index_objects_to_pending()
  refs.c: use is_dir_sep() in resolve_gitlink_ref()
  revision.h: new flag in struct rev_info wrt. worktree-related refs
2017-09-19 10:47:53 +09:00
Junio C Hamano
79553b94f9 Merge branch 'nd/worktree-kill-parse-ref'
"git branch -M a b" while on a branch that is completely unrelated
to either branch a or branch b misbehaved when multiple worktree
was in use.  This has been fixed.

* nd/worktree-kill-parse-ref:
  branch: fix branch renaming not updating HEADs correctly
2017-09-10 17:08:24 +09:00
Nguyễn Thái Ngọc Duy
d0c39a49cc revision.c: --all adds HEAD from all worktrees
Unless single_worktree is set, --all now adds HEAD from all worktrees.

Since reachable.c code does not use setup_revisions(), we need to call
other_head_refs_submodule() explicitly there to have the same effect on
"git prune", so that we won't accidentally delete objects needed by some
other HEADs.

A new FIXME is added because we would need something like

    int refs_other_head_refs(struct ref_store *, each_ref_fn, cb_data);

in addition to other_head_refs() to handle it, which might require

    int get_submodule_worktrees(const char *submodule, int flags);

It could be a separate topic to reduce the scope of this one.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-24 14:56:43 -07:00
Nguyễn Thái Ngọc Duy
31824d180d branch: fix branch renaming not updating HEADs correctly
There are two bugs that sort of work together and cause
problems. Let's start with one in replace_each_worktree_head_symref.

Before fa099d2322 (worktree.c: kill parse_ref() in favor of
refs_resolve_ref_unsafe() - 2017-04-24), this code looks like this:

    if (strcmp(oldref, worktrees[i]->head_ref))
            continue;
    set_worktree_head_symref(...);

After fa099d2322, it is possible that head_ref can be NULL. However,
the updated code takes the wrong exit. In the error case (NULL
head_ref), we should "continue;" to the next worktree. The updated
code makes us _skip_ "continue;" and update HEAD anyway.

The NULL head_ref is triggered by the second bug in add_head_info (in
the same commit). With the flag RESOLVE_REF_READING, resolve_ref_unsafe()
will abort if it cannot resolve the target ref. For orphan checkouts,
HEAD always points to an unborned branch, resolving target ref will
always fail. Now we have NULL head_ref. Now we always update HEAD.

Correct the logic in replace_ function so that we don't accidentally
update HEAD on error. As it turns out, correcting the logic bug above
breaks branch renaming completely, thanks to the second bug.

"git branch -[Mm]" does two steps (on a normal checkout, no orphan!):

 - rename the branch on disk (e.g. refs/heads/abc to refs/heads/def)
 - update HEAD if it points to the branch being renamed.

At the second step, since the branch pointed to by HEAD (e.g. "abc") no
longer exists on disk, we run into a temporary orphan checkout situation
that has been just corrected to _not_ update HEAD. But we need to update
HEAD since it's not actually an orphan checkout. We need to update HEAD
to move out of that orphan state.

Correct add_head_info(), remove RESOLVE_REF_READING flag. With the flag
gone, we should always return good "head_ref" in orphan checkouts (either
temporary or permanent). With good head_ref, things start to work again.

Noticed-by: Nish Aravamudan <nish.aravamudan@canonical.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-24 14:15:18 -07:00