When unpack-trees wants to know whether a path will
overwrite anything in the working tree, we use lstat() to
see if there is anything there. But if we are going to write
"foo/bar", we can't just lstat("foo/bar"); we need to look
for leading prefixes (e.g., "foo"). So we use the lstat cache
to find the length of the leading prefix, and copy the
filename up to that length into a temporary buffer (since
the original name is const, we cannot just stick a NUL in
it).
The copy we make goes into a PATH_MAX-sized buffer, which
will overflow if the prefix is longer than PATH_MAX. How
this happens is a little tricky, since in theory PATH_MAX is
the biggest path we will have read from the filesystem. But
this can happen if:
- the compiled-in PATH_MAX does not accurately reflect
what the filesystem is capable of
- the leading prefix is not _quite_ what is on disk; it
contains the next element from the name we are checking.
So if we want to write "aaa/bbb/ccc/ddd" and "aaa/bbb"
exists, the prefix of interest is "aaa/bbb/ccc". If
"aaa/bbb" approaches PATH_MAX, then "ccc" can overflow
it.
So this can be triggered, but it's hard to do. In
particular, you cannot just "git clone" a bogus repo. The
verify_absent checks happen before unpack-trees writes
anything to the filesystem, so there are never any leading
prefixes during the initial checkout, and the bug doesn't
trigger. And by definition, these files are larger than
PATH_MAX, so writing them will fail, and clone will
complain (though it may write a partial path, which will
cause a subsequent "git checkout" to hit the bug).
We can fix it by creating the temporary path on the heap.
The extra malloc overhead is not important, as we are
already making at least one stat() call (and probably more
for the prefix discovery).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When unpack_trees tries to write an entry to the index,
add_index_entry may report an error to stderr, but we ignore
its return value. This leads to us returning a successful
exit code for an operation that partially failed. Let's make
sure to propagate this code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most of the time the caller specifies to which destination variable
the resulting index_state should be assigned by passing a non-NULL
pointer in o->dst_index to receive that state, but for a caller that
gives a NULL o->dst_index, the resulting index simply leaked.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jn/unpack-trees-checkout-m-carry-deletion:
checkout -m: attempt merge when deletion of path was staged
unpack-trees: use 'cuddled' style for if-else cascade
unpack-trees: simplify 'all other failures' case
"git checkout -m" did not switch to another branch while carrying
the local changes forward when a path was deleted from the index.
* jn/unpack-trees-checkout-m-carry-deletion:
checkout -m: attempt merge when deletion of path was staged
unpack-trees: use 'cuddled' style for if-else cascade
unpack-trees: simplify 'all other failures' case
twoway_merge() is missing an o->gently check in the case where a file
that needs to be modified is missing from the index but present in the
old and new trees. As a result, in this case 'git checkout -m' errors
out instead of trying to perform a merge.
Fix it by checking o->gently. While at it, inline the o->gently check
into reject_merge to prevent future call sites from making the same
mistake.
Noticed by code inspection. The test for the motivating case was
added by JC.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Match the predominant style in git by following K&R style for if/else
cascades. Documentation/CodingStyle from linux.git explains:
Note that the closing brace is empty on a line of its own, _except_ in
the cases where it is followed by a continuation of the same statement,
ie a "while" in a do-statement or an "else" in an if-statement, like
this:
if (x == y) {
..
} else if (x > y) {
...
} else {
....
}
Rationale: K&R.
Also, note that this brace-placement also minimizes the number of empty
(or almost empty) lines, without any loss of readability.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the 'if (current)' block of twoway_merge, we handle the boring
errors by checking if the entry from the old tree, current index, and
new tree are present, to get a pathname for the error message from one
of them:
if (oldtree)
return o->gently ? -1 : reject_merge(oldtree, o);
if (current)
return o->gently ? -1 : reject_merge(current, o);
if (newtree)
return o->gently ? -1 : reject_merge(newtree, o);
return -1;
Since this is guarded by 'if (current)', the second test is guaranteed
to succeed. Moreover, any of the three entries, if present, would
have the same path because there is no rename detection in this code
path. Even if some day in the future the entries' paths differ, the
'current' path used in the index and worktree would presumably be the
most recognizable for the end user.
Simplify by just using 'current'.
Noticed by coverity, Id:290002
Signed-off-by: Stefan Beller <stefanbeller@gmail.com>
Improved-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
An experiment to use two files (the base file and incremental
changes relative to it) to represent the index to reduce I/O cost
of rewriting a large index when only small part of the working tree
changes.
* nd/split-index: (32 commits)
t1700: new tests for split-index mode
t2104: make sure split index mode is off for the version test
read-cache: force split index mode with GIT_TEST_SPLIT_INDEX
read-tree: note about dropping split-index mode or index version
read-tree: force split-index mode off on --index-output
rev-parse: add --shared-index-path to get shared index path
update-index --split-index: do not split if $GIT_DIR is read only
update-index: new options to enable/disable split index mode
split-index: strip pathname of on-disk replaced entries
split-index: do not invalidate cache-tree at read time
split-index: the reading part
split-index: the writing part
read-cache: mark updated entries for split index
read-cache: save deleted entries in split index
read-cache: mark new entries for split index
read-cache: split-index mode
read-cache: save index SHA-1 after reading
entry.c: update cache_changed if refresh_cache is set in checkout_entry()
cache-tree: mark istate->cache_changed on prime_cache_tree()
cache-tree: mark istate->cache_changed on cache tree update
...
* jk/xstrfmt:
setup_git_env(): introduce git_path_from_env() helper
unique_path: fix unlikely heap overflow
walker_fetch: fix minor memory leak
merge: use argv_array when spawning merge strategy
sequencer: use argv_array_pushf
setup_git_env: use git_pathdup instead of xmalloc + sprintf
use xstrfmt to replace xmalloc + strcpy/strcat
use xstrfmt to replace xmalloc + sprintf
use xstrdup instead of xmalloc + strcpy
use xstrfmt in favor of manual size calculations
strbuf: add xstrfmt helper
We often represent our strings as a counted string, i.e. a pair of
the pointer to the beginning of the string and its length, and the
string may not be NUL terminated to that length.
To compare a pair of such counted strings, unpack-trees.c and
read-cache.c implement their own name_compare() functions
identically. In addition, the cache_name_compare() function in
read-cache.c is nearly identical. The only difference is when one
string is the prefix of the other string, in which case
name_compare() returns -1/+1 to show which one is longer, and
cache_name_compare() returns the difference of the lengths to show
the same information.
Unify these three functions by using the implementation from
cache_name_compare(). This does not make any difference to the
existing and future callers, as they must be paying attention only
to the sign of the returned value (and not the magnitude) because
the original implementations of these two functions return values
returned by memcmp(3) when the one string is not a prefix of the
other string, and the only thing memcmp(3) guarantees its callers is
the sign of the returned value, not the magnitude.
Signed-off-by: Jeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In many parts of the code, we do an ugly and error-prone
malloc like:
const char *fmt = "something %s";
buf = xmalloc(strlen(foo) + 10 + 1);
sprintf(buf, fmt, foo);
This makes the code brittle, and if we ever get the
allocation wrong, is a potential heap overflow. Let's
instead favor xstrfmt, which handles the allocation
automatically, and makes the code shorter and more readable.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The large part of this patch just follows CE_ENTRY_CHANGED
marks. replace_index_entry() is updated to update
split_index->base->cache[] as well so base->cache[] does not reference
to a freed entry.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This split-index mode is designed to keep write cost proportional to
the number of changes the user has made, not the size of the work
tree. (Read cost is another matter, to be dealt separately.)
This mode stores index info in a pair of $GIT_DIR/index and
$GIT_DIR/sharedindex.<SHA-1>. sharedindex is large and unchanged over
time while "index" is smaller and updated often. Format details are in
index-format.txt, although not everything is implemented in this
patch.
Shared indexes are not automatically removed, because it's unclear if
the shared index is needed by any (even temporary) indexes by just
looking at it. After a while you'll collect stale shared indexes. The
good news is one shared index is useable for long, until
$GIT_DIR/index becomes too big and sluggish that the new shared index
must be created.
The safest way to clean shared indexes is to turn off split index
mode, so shared files are all garbage, delete them all, then turn on
split index mode again.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Also update SHA-1 after writing. If we do not do that, the second
read_index() will see "initialized" variable already set and not read
.git/index again, which is fine, except istate->sha1 now has a stale
value.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Other fill_stat_cache_info() is on new entries, which should set
CE_ENTRY_ADDED in cache_changed, so we're safe.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Improvements to our hash table to get it to meet the needs of the
msysgit fscache project, with some nice performance improvements.
* kb/fast-hashmap:
name-hash: retire unused index_name_exists()
hashmap.h: use 'unsigned int' for hash-codes everywhere
test-hashmap.c: drop unnecessary #includes
.gitignore: test-hashmap is a generated file
read-cache.c: fix memory leaks caused by removed cache entries
builtin/update-index.c: cleanup update_one
fix 'git update-index --verbose --again' output
remove old hash.[ch] implementation
name-hash.c: remove cache entries instead of marking them CE_UNHASHED
name-hash.c: use new hash map implementation for cache entries
name-hash.c: remove unreferenced directory entries
name-hash.c: use new hash map implementation for directories
diffcore-rename.c: use new hash map implementation
diffcore-rename.c: simplify finding exact renames
diffcore-rename.c: move code around to prepare for the next patch
buitin/describe.c: use new hash map implementation
add a hashtable implementation that supports O(1) removal
submodule: don't access the .gitmodules cache entry after removing it
"git am --abort" sometimes complained about not being able to write
a tree with an 0{40} object in it.
* jk/two-way-merge-corner-case-fix:
t1005: add test for "read-tree --reset -u A B"
t1005: reindent
unpack-trees: fix "read-tree -u --reset A B" with conflicted index
Some buffers created with PATH_MAX length are not checked when being
written, and can overflow if PATH_MAX is not big enough to hold the
path.
Replace those buffers by strbufs so that their size is automatically
grown if necessary. They are created as static local variables to avoid
reallocating memory on each call. Note that prefix_filename() returns
this static buffer so each callers should copy or use the string
immediately (this is currently true).
Reported-by: Wataru Noguchi <wnoguchi.0727@gmail.com>
Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a rather longstanding corner-case bug in twoway "reset to
there" merge, which is most often seen in "git am --abort".
* jk/two-way-merge-corner-case-fix:
t1005: add test for "read-tree --reset -u A B"
t1005: reindent
unpack-trees: fix "read-tree -u --reset A B" with conflicted index
The new hashmap implementation supports remove, so really remove unused
cache entries from the name hashmap instead of just marking them.
The CE_UNHASHED flag and CE_STATE_MASK are no longer needed.
Keep the CE_HASHED flag to prevent adding entries twice.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Note: the "ce->next = NULL;" in unpack-trees.c::do_add_entry can safely be
removed, as ce->next (now ce->ent.next) is always properly initialized in
name-hash.c::hash_index_entry.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we call "read-tree --reset -u HEAD ORIG_HEAD", the first thing we
do with the index is to call read_cache_unmerged. Originally that
would read the index, leaving aside any unmerged entries. However, as
of d1a43f2 (reset --hard/read-tree --reset -u: remove unmerged new
paths, 2008-10-15), it actually creates a new cache entry to serve as
a placeholder, so that we later know to update the working tree.
However, we later noticed that the sha1 of that unmerged entry was
just copied from some higher stage, leaving you with random content in
the index. That was fixed by e11d7b5 ("reset --merge": fix unmerged
case, 2009-12-31), which instead puts the null sha1 into the newly
created entry, and sets a CE_CONFLICTED flag. At the same time, it
teaches the unpack-trees machinery to pay attention to this flag, so
that oneway_merge throws away the current value.
However, it did not update the code paths for twoway_merge, which is
where we end up in the two-way read-tree with --reset. We notice that
the HEAD and ORIG_HEAD versions are the same, and say "oh, we can just
reuse the current version". But that's not true. The current version
is bogus.
Notice this case and make sure we do not keep the bogus entry; either
we do not have that path in the tree we are moving to (i.e. remove
it), or we want to have the cache entry we created for the tree we are
moving to (i.e. resolve by explicitly saying the "newtree" version is
what we want).
[jc: this is from the almost year-old $gmane/212316]
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Each caller of index_name_exists() knows whether it is looking for a
directory or a file, and can avoid the unnecessary indirection of
index_name_exists() by instead calling index_dir_exists() or
index_file_exists() directly.
Invoking the appropriate search function explicitly will allow a
subsequent patch to relieve callers of the artificial burden of having
to add a trailing '/' to the pathname given to index_dir_exists().
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before overwriting the destination index, first let's discard its
contents.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Tested-by: Лежанкин Иван <abyss.7@gmail.com> wrote:
Reviewed-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
I attempted to make index_state->cache[] a "const struct cache_entry **"
to find out how existing entries in index are modified and where. The
question I have is what do we do if we really need to keep track of on-disk
changes in the index. The result is
- diff-lib.c: setting CE_UPTODATE
- name-hash.c: setting CE_HASHED
- preload-index.c, read-cache.c, unpack-trees.c and
builtin/update-index: obvious
- entry.c: write_entry() may refresh the checked out entry via
fill_stat_cache_info(). This causes "non-const struct cache_entry
*" in builtin/apply.c, builtin/checkout-index.c and
builtin/checkout.c
- builtin/ls-files.c: --with-tree changes stagemask and may set
CE_UPDATE
Of these, write_entry() and its call sites are probably most
interesting because it modifies on-disk info. But this is stat info
and can be retrieved via refresh, at least for porcelain
commands. Other just uses ce_flags for local purposes.
So, keeping track of "dirty" entries is just a matter of setting a
flag in index modification functions exposed by read-cache.c. Except
unpack-trees, the rest of the code base does not do anything funny
behind read-cache's back.
The actual patch is less valueable than the summary above. But if
anyone wants to re-identify the above sites. Applying this patch, then
this:
diff --git a/cache.h b/cache.h
index 430d021..1692891 100644
--- a/cache.h
+++ b/cache.h
@@ -267,7 +267,7 @@ static inline unsigned int canon_mode(unsigned int mode)
#define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)
struct index_state {
- struct cache_entry **cache;
+ const struct cache_entry **cache;
unsigned int version;
unsigned int cache_nr, cache_alloc, cache_changed;
struct string_list *resolve_undo;
will help quickly identify them without bogus warnings.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If o->merge is set, the struct traverse_info member conflicts is shifted
left in unpack_callback, then passed through traverse_trees_recursive
to unpack_nondirectories, where it is shifted right before use. Stop
the shifting and just pass the conflict bit mask as is. Rename the
member to df_conflicts to prove that it isn't used anywhere else.
Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The merge functions duplicate entries as needed and they don't free
them. Release them in unpack_nondirectories, the same function
where they were allocated, after we're done.
As suggested by Felipe, use the same loop style (zero-based for loop)
for freeing as for allocating.
Improved-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the type merge_fn_t to accept the array of cache_entry pointers
as const pointers to const pointers. This documents the fact that the
merge functions don't modify the cache_entry contents or replace any of
the pointers in the array.
Only a single cast is necessary in unpack_nondirectories because adding
two const modifiers at once is not allowed in C. The cast is safe in
that it doesn't mask any modfication; call_unpack_fn only needs the
array for reading.
Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add const to struct cache_entry pointers throughout the tree which are
only used for reading. This allows callers to pass in const pointers.
Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Duplicate the merge entry right away and work with that instead of
modifying the entry we got and duplicating it only at the end of
the function. Then mark that pointer const to document that we
don't modify the referenced cache_entry.
This change is safe because all existing merge functions call
merged_entry just before returning (or not at all), i.e. they don't
care about changes to the referenced cache_entry after the call.
unpack_nondirectories and unpack_index_entry, which call the merge
functions through call_unpack_fn, aren't interested in such changes
neither.
The change complicates merged_entry a bit because we have to free the
copy if we error out, but allows callers to pass a const pointer.
Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While we're add it, mark the struct cache_entry pointer of add_entry
const because we only read from it and this allows callers to pass in
const pointers.
Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a new command "git check-ignore" for debugging .gitignore
files.
The variable names may want to get cleaned up but that can be done
in-tree.
* as/check-ignore:
clean.c, ls-files.c: respect encapsulation of exclude_list_groups
t0008: avoid brace expansion
add git-check-ignore sub-command
setup.c: document get_pathspec()
add.c: extract new die_if_path_beyond_symlink() for reuse
add.c: extract check_path_for_gitlink() from treat_gitlinks() for reuse
pathspec.c: rename newly public functions for clarity
add.c: move pathspec matchers into new pathspec.c for reuse
add.c: remove unused argument from validate_pathspec()
dir.c: improve docs for match_pathspec() and match_pathspec_depth()
dir.c: provide clear_directory() for reclaiming dir_struct memory
dir.c: keep track of where patterns came from
dir.c: use a single struct exclude_list per source of excludes
Conflicts:
builtin/ls-files.c
dir.c
Refactor and generally clean up the directory traversal API
implementation.
* as/dir-c-cleanup:
dir.c: rename free_excludes() to clear_exclude_list()
dir.c: refactor is_path_excluded()
dir.c: refactor is_excluded()
dir.c: refactor is_excluded_from_list()
dir.c: rename excluded() to is_excluded()
dir.c: rename excluded_from_list() to is_excluded_from_list()
dir.c: rename path_excluded() to is_path_excluded()
dir.c: rename cryptic 'which' variable to more consistent name
Improve documentation and comments regarding directory traversal API
api-directory-listing.txt: update to match code
Previously each exclude_list could potentially contain patterns
from multiple sources. For example dir->exclude_list[EXC_FILE]
would typically contain patterns from .git/info/exclude and
core.excludesfile, and dir->exclude_list[EXC_DIRS] could contain
patterns from multiple per-directory .gitignore files during
directory traversal (i.e. when dir->exclude_stack was more than
one item deep).
We split these composite exclude_lists up into three groups of
exclude_lists (EXC_CMDL / EXC_DIRS / EXC_FILE as before), so that each
exclude_list now contains patterns from a single source. This will
allow us to cleanly track the origin of each pattern simply by adding
a src field to struct exclude_list, rather than to struct exclude,
which would make memory management of the source string tricky in the
EXC_DIRS case where its contents are dynamically generated.
Similarly, by moving the filebuf member from struct exclude_stack to
struct exclude_list, it allows us to track and subsequently free
memory buffers allocated during the parsing of all exclude files,
rather than only tracking buffers allocated for files in the EXC_DIRS
group.
Signed-off-by: Adam Spiers <git@adamspiers.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is clearer to use a 'clear_' prefix for functions which empty
and deallocate the contents of a data structure without freeing
the structure itself, and a 'free_' prefix for functions which
also free the structure itself.
http://article.gmane.org/gmane.comp.version-control.git/206128
Signed-off-by: Adam Spiers <git@adamspiers.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Continue adopting clearer names for exclude functions. This 'is_*'
naming pattern for functions returning booleans was discussed here:
http://thread.gmane.org/gmane.comp.version-control.git/204661/focus=204924
Also adjust their callers as necessary.
Signed-off-by: Adam Spiers <git@adamspiers.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
