delta/git.git/name-hash.c, branch sb/string-list-split-appends

convert trivial cases to FLEX_ARRAY macros

2016-02-22T22:51:09+00:00

Using FLEX_ARRAY macros reduces the amount of manual
computation size we have to do. It also ensures we don't
overflow size_t, and it makes sure we write the same number
of bytes that we allocated.

Signed-off-by: Jeff King 
Signed-off-by: Junio C Hamano

name-hash: don't reuse cache_entry in dir_entry

2015-10-21T19:47:38+00:00

Stop reusing cache_entry in dir_entry; doing so causes a
use-after-free bug.

During merges, we free entries that we no longer need in the
destination index.  But those entries might have also been stored in
the dir_entry cache, and when a later call to add_to_index found them,
they would be used after being freed.

To prevent this, change dir_entry to store a copy of the name instead
of a pointer to a cache_entry.  This entails some refactoring of code
that expects the cache_entry.

Keith McGuigan  diagnosed this bug and wrote
the initial patch, but this version does not use any of Keith's code.

Helped-by: Keith McGuigan 
Helped-by: Junio C Hamano 
Signed-off-by: David Turner 
Signed-off-by: Junio C Hamano

hashmap: add simplified hashmap_get_from_hash() API

2014-07-07T20:56:35+00:00

Hashmap entries are typically looked up by just a key. The hashmap_get()
API expects an initialized entry structure instead, to support compound
keys. This flexibility is currently only needed by find_dir_entry() in
name-hash.c (and compat/win32/fscache.c in the msysgit fork). All other
(currently five) call sites of hashmap_get() have to set up a near emtpy
entry structure, resulting in duplicate code like this:

  struct hashmap_entry keyentry;
  hashmap_entry_init(&keyentry, hash(key));
  return hashmap_get(map, &keyentry, key);

Add a hashmap_get_from_hash() API that allows hashmap lookups by just
specifying the key and its hash code, i.e.:

  return hashmap_get_from_hash(map, hash(key), key);

Signed-off-by: Karsten Blees 
Signed-off-by: Junio C Hamano

name-hash.c: replace cache_name_compare() with memcmp(3)

2014-06-20T17:08:10+00:00

The same_name() private function wants a quick-and-exact check to
see if they two names are byte-for-byte identical first and then
fall back to the slow path.  Use memcmp(3) for the former to make it
clear that we do not want any "name" specific comparison.

Signed-off-by: Jeremiah Mahler 
Signed-off-by: Junio C Hamano

name-hash: retire unused index_name_exists()

2014-02-24T23:26:33+00:00

db5360f3f496 (name-hash: refactor polymorphic index_name_exists();
2013-09-17) split index_name_exists() into index_file_exists() and
index_dir_exists() but retained index_name_exists() as a thin wrapper
to avoid disturbing possible in-flight topics. Since this change
landed in 'master' some time ago and there are no in-flight topics
referencing index_name_exists(), retire it.

Signed-off-by: Eric Sunshine 
Signed-off-by: Junio C Hamano

name-hash.c: remove cache entries instead of marking them CE_UNHASHED

2013-11-18T21:04:24+00:00

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 
Signed-off-by: Junio C Hamano

name-hash.c: use new hash map implementation for cache entries

2013-11-18T21:04:24+00:00

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 
Signed-off-by: Junio C Hamano

name-hash.c: remove unreferenced directory entries

2013-11-18T21:04:24+00:00

The new hashmap implementation supports remove, so remove and free
directory entries that are no longer referenced by active cache entries.

Signed-off-by: Karsten Blees 
Signed-off-by: Junio C Hamano

name-hash.c: use new hash map implementation for directories

2013-11-18T21:04:23+00:00

Signed-off-by: Karsten Blees 
Signed-off-by: Junio C Hamano

name-hash: stop storing trailing '/' on paths in index_state.dir_hash

2013-09-17T17:08:07+00:00

When 5102c617 (Add case insensitivity support for directories when using
git status, 2010-10-03) added directories to the name-hash there was
only a single hash table in which both real cache entries and leading
directory prefixes were registered. To distinguish between the two types
of entries, directories were stored with a trailing '/'.

2092678c (name-hash.c: fix endless loop with core.ignorecase=true,
2013-02-28), however, moved directories to a separate hash table
(index_state.dir_hash) but retained the (now) redundant trailing '/',
thus callers continue to bear the burden of ensuring the slash's
presence before searching the index for a directory. Eliminate this
redundancy by storing paths in the dir-hash without the trailing '/'.

An important benefit of this change is that it eliminates undocumented
and dangerous behavior of dir.c:directory_exists_in_index_icase() in
which it assumes not only that it can validly access one character
beyond the end of its incoming directory argument, but also that that
character will unconditionally be a '/'. This perilous behavior was
"tolerated" because the string passed in by its lone caller always had a
'/' in that position, however, things broke [1] when 2eac2a4c (ls-files
-k: a directory only can be killed if the index has a non-directory,
2013-08-15) added a new caller which failed to respect the undocumented
assumption.

[1]: http://thread.gmane.org/gmane.comp.version-control.git/232727

Signed-off-by: Eric Sunshine 
Signed-off-by: Junio C Hamano