Commit graph

6117 commits

Author SHA1 Message Date
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
brian m. carlson a98e6101f0 refs: convert resolve_gitlink_ref to struct object_id
Convert the declaration and definition of resolve_gitlink_ref to use
struct object_id and apply the following semantic patch:

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

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

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 0155f710b8 refs: convert reflog_expire parameter to struct object_id
reflog_expire already used struct object_id internally, but it did not
take it as a parameter.  Adjust the parameter (and the callers) to pass
a pointer to struct object_id instead of a pointer to unsigned char.
Remove the temporary inserted earlier as it is no longer required.

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 8eb36d9422 refs: convert read_ref_at to struct object_id
Convert the callers and internals, including struct read_ref_at_cb, of
read_ref_at to use struct object_id.

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 b420d90980 refs: convert peel_ref to struct object_id
Convert peel_ref (and its corresponding backend) to struct object_id.

This transformation was done with an update to the declaration,
definition, comments, and test helper and the following semantic patch:

@@
expression E1, E2;
@@
- peel_ref(E1, E2.hash)
+ peel_ref(E1, &E2)

@@
expression E1, E2;
@@
- peel_ref(E1, E2->hash)
+ peel_ref(E1, E2)

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 188960b4d6 builtin/pack-objects: convert to struct object_id
This is one of the last unconverted callers to peel_ref.  While we're
fixing that, convert the rest of the file, since it will need to be
converted at some point anyway.

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 206649672e pack-bitmap: convert traverse_bitmap_commit_list to object_id
Convert traverse_bitmap_commit_list and the callbacks it takes to use a
pointer to struct object_id.

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 334dc52f49 refs: convert dwim_log to struct object_id
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 b8acac54c8 builtin/reflog: convert remaining unsigned char uses to object_id
Convert the remaining uses of unsigned char [20] to struct object_id.
This conversion is needed for dwim_log.

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 cca5fa6406 refs: convert dwim_ref and expand_ref to struct object_id
All of the callers of these functions just pass the hash member of a
struct object_id, so convert them to use a pointer to struct object_id
directly.  Insert a check for NULL in expand_ref on a temporary basis;
this check can be removed when resolve_ref_unsafe is converted as well.

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 34c290a6fc refs: convert read_ref and read_ref_full to object_id
All but two of the call sites already have parameters using the hash
parameter of struct object_id, so convert them to take a pointer to the
struct directly.  Also convert refs_read_refs_full, the underlying
implementation.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16 11:05:50 +09:00
brian m. carlson 0f2dc722dd refs: convert resolve_refdup and refs_resolve_refdup to struct object_id
All of the callers already pass the hash member of struct object_id, so
update them to pass a pointer to the struct directly,

This transformation was done with an update to declaration and
definition and the following semantic patch:

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

@@
expression E1, E2, E3, E4;
@@
- resolve_refdup(E1, E2, E3->hash, E4)
+ resolve_refdup(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 11:05:50 +09:00
brian m. carlson 6ccac9eed5 Convert check_connected to use struct object_id
Convert check_connected and the callbacks it takes to use struct
object_id.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16 11:05:50 +09:00
brian m. carlson 89f3bbdd3b refs: update ref transactions to use struct object_id
Update the ref transaction code to use struct object_id.  Remove one
NULL pointer check which was previously inserted around a dereference;
since we now pass a pointer to struct object_id directly through, the
code we're calling handles this for us.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16 11:05:50 +09:00
brian m. carlson ae077771b0 refs: convert update_ref and refs_update_ref to use struct object_id
Convert update_ref, refs_update_ref, and write_pseudoref to use struct
object_id.  Update the existing callers as well.  Remove update_ref_oid,
as it is no longer needed.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16 11:05:50 +09:00
brian m. carlson 2616a5e508 refs: convert delete_ref and refs_delete_ref to struct object_id
Convert delete_ref and refs_delete_ref to take a pointer to struct
object_id.  Update the documentation accordingly, including referring to
null_oid in lowercase, as it is not a #define constant.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16 11:05:50 +09:00
Junio C Hamano 7245ee3d6c Merge branch 'ds/avoid-overflow-in-midpoint-computation'
Code clean-up.

* ds/avoid-overflow-in-midpoint-computation:
  cleanup: fix possible overflow errors in binary search
2017-10-11 14:52:24 +09:00
Derrick Stolee 19716b21a4 cleanup: fix possible overflow errors in binary search
A common mistake when writing binary search is to allow possible
integer overflow by using the simple average:

	mid = (min + max) / 2;

Instead, use the overflow-safe version:

	mid = min + (max - min) / 2;

This translation is safe since the operation occurs inside a loop
conditioned on "min < max". The included changes were found using
the following git grep:

	git grep '/ *2;' '*.c'

Making this cleanup will prevent future review friction when a new
binary search is contructed based on existing code.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-10 08:57:24 +09:00
Junio C Hamano 932b573406 Merge branch 'ks/branch-tweak-error-message-for-extra-args'
Error message tweak.

* ks/branch-tweak-error-message-for-extra-args:
  branch: change the error messages to be more meaningful
2017-10-07 16:27:55 +09:00
Junio C Hamano da15b78e52 Merge branch 'jk/ui-color-always-to-auto'
Fix regression of "git add -p" for users with "color.ui = always"
in their configuration, by merging the topic below and adjusting it
for the 'master' front.

* jk/ui-color-always-to-auto:
  t7301: use test_terminal to check color
  t4015: use --color with --color-moved
  color: make "always" the same as "auto" in config
  provide --color option for all ref-filter users
  t3205: use --color instead of color.branch=always
  t3203: drop "always" color test
  t6006: drop "always" color config tests
  t7502: use diff.noprefix for --verbose test
  t7508: use test_terminal for color output
  t3701: use test-terminal to collect color output
  t4015: prefer --color to -c color.diff=always
  test-terminal: set TERM=vt100
2017-10-07 16:27:55 +09:00
Junio C Hamano 5261fefa4a Merge branch 'ma/builtin-unleak'
Many variables that points at a region of memory that will live
throughout the life of the program have been marked with UNLEAK
marker to help the leak checkers concentrate on real leaks..

* ma/builtin-unleak:
  builtin/: add UNLEAKs
2017-10-07 16:27:55 +09:00
Junio C Hamano cfa0fd0ffc Merge branch 'sb/branch-avoid-repeated-strbuf-release'
* sb/branch-avoid-repeated-strbuf-release:
  branch: reset instead of release a strbuf
2017-10-07 16:27:54 +09:00
Junio C Hamano e46ebc2754 Merge branch 'rs/cleanup-strbuf-users'
Code clean-up.

* rs/cleanup-strbuf-users:
  graph: use strbuf_addchars() to add spaces
  use strbuf_addstr() for adding strings to strbufs
  path: use strbuf_add_real_path()
2017-10-05 13:48:19 +09:00
Junio C Hamano efe9d6ce33 Merge branch 'rs/resolve-ref-optional-result'
Code clean-up.

* rs/resolve-ref-optional-result:
  refs: pass NULL to resolve_refdup() if hash is not needed
  refs: pass NULL to refs_resolve_refdup() if hash is not needed
2017-10-05 13:48:19 +09:00
Stefan Beller a9155c50bd branch: reset instead of release a strbuf
Our documentation advises to not re-use a strbuf, after strbuf_release
has been called on it. Use the proper reset instead.

Currently 'strbuf_release' releases and re-initializes the strbuf, so it
is safe, but slow. 'strbuf_reset' only resets the internal length variable,
such that this could also be accounted for as a micro-optimization.

Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-04 15:21:31 +09:00
Kaartic Sivaraam f777623514 branch: change the error messages to be more meaningful
The error messages shown when the branch command is misused
by supplying it wrong number of parameters wasn't meaningful.
That's because it used the the phrase "too many branches"
assuming all parameters to be "valid" branch names. It's not
always the case as exemplified below,

        $ git branch
          foo
        * master

        $ git branch -m foo foo old
        fatal: too many branches for a rename operation

Change the messages to be more general thus making no assumptions
about the "parameters".

Signed-off-by: Kaartic Sivaraam <kaarticsivaraam91196@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-04 13:08:17 +09:00
Junio C Hamano aebd23506e Merge branch 'jk/ui-color-always-to-auto-maint' into jk/ui-color-always-to-auto
* jk/ui-color-always-to-auto-maint:
  color: make "always" the same as "auto" in config
  provide --color option for all ref-filter users
  t3205: use --color instead of color.branch=always
  t3203: drop "always" color test
  t6006: drop "always" color config tests
  t7502: use diff.noprefix for --verbose test
  t7508: use test_terminal for color output
  t3701: use test-terminal to collect color output
  t4015: prefer --color to -c color.diff=always
  test-terminal: set TERM=vt100
2017-10-04 12:04:47 +09:00
Jeff King 0c88bf5050 provide --color option for all ref-filter users
When ref-filter learned about want_color() in 11b087adfd
(ref-filter: consult want_color() before emitting colors,
2017-07-13), it became useful to be able to turn colors off
and on for specific commands. For git-branch, you can do so
with --color/--no-color.

But for git-for-each-ref and git-tag, the other users of
ref-filter, you have no option except to tweak the
"color.ui" config setting. Let's give both of these commands
the usual color command-line options.

This is a bit more obvious as a method for overriding the
config. And it also prepares us for the behavior of "always"
changing (so that we are still left with a way of forcing
color when our output goes to a non-terminal).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-04 11:35:29 +09:00
Junio C Hamano cb1083ca23 Merge branch 'jk/read-in-full'
Code clean-up to prevent future mistakes by copying and pasting
code that checks the result of read_in_full() function.

* jk/read-in-full:
  worktree: check the result of read_in_full()
  worktree: use xsize_t to access file size
  distinguish error versus short read from read_in_full()
  avoid looking at errno for short read_in_full() returns
  prefer "!=" when checking read_in_full() result
  notes-merge: drop dead zero-write code
  files-backend: prefer "0" for write_in_full() error check
2017-10-03 15:42:49 +09:00
Junio C Hamano d4e93836a6 Merge branch 'jk/no-optional-locks'
Some commands (most notably "git status") makes an opportunistic
update when performing a read-only operation to help optimize later
operations in the same repository.  The new "--no-optional-locks"
option can be passed to Git to disable them.

* jk/no-optional-locks:
  git: add --no-optional-locks option
2017-10-03 15:42:49 +09:00
Junio C Hamano 3b48045c6c Merge branch 'sd/branch-copy'
"git branch" learned "-c/-C" to create a new branch by copying an
existing one.

* sd/branch-copy:
  branch: fix "copy" to never touch HEAD
  branch: add a --copy (-c) option to go with --move (-m)
  branch: add test for -m renaming multiple config sections
  config: create a function to format section headers
2017-10-03 15:42:48 +09:00
Junio C Hamano b2a2c4d809 Merge branch 'bc/rev-parse-parseopt-fix'
Recent versions of "git rev-parse --parseopt" did not parse the
option specification that does not have the optional flags (*=?!)
correctly, which has been corrected.

* bc/rev-parse-parseopt-fix:
  parse-options: only insert newline in help text if needed
  parse-options: write blank line to correct output stream
  t0040,t1502: Demonstrate parse_options bugs
  git-rebase: don't ignore unexpected command line arguments
  rev-parse parseopt: interpret any whitespace as start of help text
  rev-parse parseopt: do not search help text for flag chars
  t1502: demonstrate rev-parse --parseopt option mis-parsing
2017-10-03 15:42:47 +09:00
Junio C Hamano 5f3108b7b6 Merge branch 'js/rebase-i-final'
The final batch to "git rebase -i" updates to move more code from
the shell script to C.

* js/rebase-i-final:
  rebase -i: rearrange fixup/squash lines using the rebase--helper
  t3415: test fixup with wrapped oneline
  rebase -i: skip unnecessary picks using the rebase--helper
  rebase -i: check for missing commits in the rebase--helper
  t3404: relax rebase.missingCommitsCheck tests
  rebase -i: also expand/collapse the SHA-1s via the rebase--helper
  rebase -i: do not invent onelines when expanding/collapsing SHA-1s
  rebase -i: remove useless indentation
  rebase -i: generate the script via rebase--helper
  t3415: verify that an empty instructionFormat is handled as before
2017-10-03 15:42:47 +09:00
René Scharfe 72d4a9a721 use strbuf_addstr() for adding strings to strbufs
Use strbuf_addstr() instead of strbuf_addf() for adding strings.  That's
simpler and makes the intent clearer.

Patch generated by Coccinelle and contrib/coccinelle/strbuf.cocci;
adjusted indentation in refs/packed-backend.c manually.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-02 13:13:46 +09:00
Martin Ågren 886e1084d7 builtin/: add UNLEAKs
Add some UNLEAKs where we are about to return from `cmd_*`. UNLEAK the
variables in the same order as we've declared them. While addressing
`msg` in builtin/tag.c, convert the existing `strbuf_release()` calls as
well.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-02 13:03:10 +09:00
René Scharfe efbd4fdfc9 refs: pass NULL to resolve_refdup() if hash is not needed
This allows us to get rid of several write-only variables.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-01 17:27:14 +09:00
Junio C Hamano 69c54c7284 Merge branch 'ma/leakplugs'
Memory leaks in various codepaths have been plugged.

* ma/leakplugs:
  pack-bitmap[-write]: use `object_array_clear()`, don't leak
  object_array: add and use `object_array_pop()`
  object_array: use `object_array_clear()`, not `free()`
  leak_pending: use `object_array_clear()`, not `free()`
  commit: fix memory leak in `reduce_heads()`
  builtin/commit: fix memory leak in `prepare_index()`
2017-09-29 11:23:43 +09:00
Junio C Hamano 14a8168e2f Merge branch 'rj/no-sign-compare'
Many codepaths have been updated to squelch -Wsign-compare
warnings.

* rj/no-sign-compare:
  ALLOC_GROW: avoid -Wsign-compare warnings
  cache.h: hex2chr() - avoid -Wsign-compare warnings
  commit-slab.h: avoid -Wsign-compare warnings
  git-compat-util.h: xsize_t() - avoid -Wsign-compare warnings
2017-09-29 11:23:42 +09:00
Junio C Hamano 8096e1d385 Merge branch 'jt/fast-export-copy-modify-fix'
"git fast-export" with -M/-C option issued "copy" instruction on a
path that is simultaneously modified, which was incorrect.

* jt/fast-export-copy-modify-fix:
  fast-export: do not copy from modified file
2017-09-29 11:23:42 +09:00
Junio C Hamano 8c1bc7c244 Merge branch 'mk/describe-match-with-all'
"git describe --match <pattern>" has been taught to play well with
the "--all" option.

* mk/describe-match-with-all:
  describe: teach --match to handle branches and remotes
2017-09-29 11:23:41 +09:00
Junio C Hamano 73ecdc606e Merge branch 'rs/resolve-ref-optional-result'
Code clean-up.

* rs/resolve-ref-optional-result:
  refs: pass NULL to resolve_ref_unsafe() if hash is not needed
  refs: pass NULL to refs_resolve_ref_unsafe() if hash is not needed
  refs: make sha1 output parameter of refs_resolve_ref_unsafe() optional
2017-09-28 14:47:56 +09:00
Junio C Hamano 59373a4e03 Merge branch 'jk/fallthrough'
Many codepaths have been updated to squelch -Wimplicit-fallthrough
warnings from Gcc 7 (which is a good code hygiene).

* jk/fallthrough:
  consistently use "fallthrough" comments in switches
  curl_trace(): eliminate switch fallthrough
  test-line-buffer: simplify command parsing
2017-09-28 14:47:53 +09:00
Junio C Hamano bfbc2fccfd Merge branch 'jk/diff-blob'
"git cat-file --textconv" started segfaulting recently, which
has been corrected.

* jk/diff-blob:
  cat-file: handle NULL object_context.path
2017-09-28 14:47:53 +09:00
Junio C Hamano a515136c52 Merge branch 'jk/describe-omit-some-refs'
"git describe --match" learned to take multiple patterns in v2.13
series, but the feature ignored the patterns after the first one
and did not work at all.  This has been fixed.

* jk/describe-omit-some-refs:
  describe: fix matching to actually match all patterns
2017-09-28 14:47:52 +09:00
Jeff King 27344d6a6c git: add --no-optional-locks option
Some tools like IDEs or fancy editors may periodically run
commands like "git status" in the background to keep track
of the state of the repository. Some of these commands may
refresh the index and write out the result in an
opportunistic way: if they can get the index lock, then they
update the on-disk index with any updates they find. And if
not, then their in-core refresh is lost and just has to be
recomputed by the next caller.

But taking the index lock may conflict with other operations
in the repository. Especially ones that the user is doing
themselves, which _aren't_ opportunistic. In other words,
"git status" knows how to back off when somebody else is
holding the lock, but other commands don't know that status
would be happy to drop the lock if somebody else wanted it.

There are a couple possible solutions:

  1. Have some kind of "pseudo-lock" that allows other
     commands to tell status that they want the lock.

     This is likely to be complicated and error-prone to
     implement (and maybe even impossible with just
     dotlocks to work from, as it requires some
     inter-process communication).

  2. Avoid background runs of commands like "git status"
     that want to do opportunistic updates, preferring
     instead plumbing like diff-files, etc.

     This is awkward for a couple of reasons. One is that
     "status --porcelain" reports a lot more about the
     repository state than is available from individual
     plumbing commands. And two is that we actually _do_
     want to see the refreshed index. We just don't want to
     take a lock or write out the result. Whereas commands
     like diff-files expect us to refresh the index
     separately and write it to disk so that they can depend
     on the result. But that write is exactly what we're
     trying to avoid.

  3. Ask "status" not to lock or write the index.

     This is easy to implement. The big downside is that any
     work done in refreshing the index for such a call is
     lost when the process exits. So a background process
     may end up re-hashing a changed file multiple times
     until the user runs a command that does an index
     refresh themselves.

This patch implements the option 3. The idea (and the test)
is largely stolen from a Git for Windows patch by Johannes
Schindelin, 67e5ce7f63 (status: offer *not* to lock the
index and update it, 2016-08-12). The twist here is that
instead of making this an option to "git status", it becomes
a "git" option and matching environment variable.

The reason there is two-fold:

  1. An environment variable is carried through to
     sub-processes. And whether an invocation is a
     background process or not should apply to the whole
     process tree. So you could do "git --no-optional-locks
     foo", and if "foo" is a script or alias that calls
     "status", you'll still get the effect.

  2. There may be other programs that want the same
     treatment.

     I've punted here on finding more callers to convert,
     since "status" is the obvious one to call as a repeated
     background job. But "git diff"'s opportunistic refresh
     of the index may be a good candidate.

The test is taken from 67e5ce7f63, and it's worth repeating
Johannes's explanation:

  Note that the regression test added in this commit does
  not *really* verify that no index.lock file was written;
  that test is not possible in a portable way. Instead, we
  verify that .git/index is rewritten *only* when `git
  status` is run without `--no-optional-locks`.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-27 16:11:01 +09:00
Jeff King 8a1a8d2ad1 worktree: check the result of read_in_full()
We try to read "len" bytes into a buffer and just assume
that it happened correctly. In practice this should usually
be the case, since we just stat'd the file to get the
length.  But we could be fooled by transient errors or by
other processes racily truncating the file.

Let's be more careful. There's a slim chance this could
catch a real error, but it also prevents people and tools
from getting worried while reading the code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-27 15:46:05 +09:00
Jeff King 228740b67b worktree: use xsize_t to access file size
To read the "gitdir" file into memory, we stat the file and
allocate a buffer. But we store the size in an "int", which
may be truncated. We should use a size_t and xsize_t(),
which will detect truncation.

An overflow is unlikely for a "gitdir" file, but it's a good
practice to model.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-27 15:45:57 +09:00
Jeff King 41dcc4dccc distinguish error versus short read from read_in_full()
Many callers of read_in_full() expect to see the exact
number of bytes requested, but their error handling lumps
together true read errors and short reads due to unexpected
EOF.

We can give more specific error messages by separating these
cases (showing errno when appropriate, and otherwise
describing the short read).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-27 15:45:24 +09:00
Jeff King 61d36330b4 prefer "!=" when checking read_in_full() result
Comparing the result of read_in_full() using less-than is
potentially dangerous, as a negative return value may be
converted to an unsigned type and be considered a success.
This is discussed further in 561598cfcf (read_pack_header:
handle signed/unsigned comparison in read result,
2017-09-13).

Each of these instances is actually fine in practice:

 - in get-tar-commit-id, the HEADERSIZE macro expands to a
   signed integer. If it were switched to an unsigned type
   (e.g., a size_t), then it would be a bug.

 - the other two callers check for a short read only after
   handling a negative return separately. This is a fine
   practice, but we'd prefer to model "!=" as a general
   rule.

So all of these cases can be considered cleanups and not
actual bugfixes.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-27 15:45:24 +09:00