[PATCH 2/3] name-hash: stop storing trailing '/' on paths in index_state.dir_hash
- From
Eric Sunshine <sunshine@sunshineco.com>
- Date
- Sep 13, 2013, 11:15 UTC
- Message-ID
- <1379070943-36595-3-git-send-email-sunshine@sunshineco.com>
- In-Reply-To
- <1379070943-36595-1-git-send-email-sunshine@sunshineco.com>
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 still bear the burden of ensuring its presence before searching via index_dir_exists(). 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 <sunshine@sunshineco.com> --- dir.c | 2 +- name-hash.c | 9 +++++---- read-cache.c | 2 +- 3 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/dir.c b/dir.c index 0080673..69d04a0 100644 --- a/dir.c +++ b/dir.c @@ -890,7 +890,7 @@ enum exist_status { */ static enum exist_status directory_exists_in_index_icase(const char *dirname, int len) { - const struct cache_entry *ce = cache_dir_exists(dirname, len + 1); + const struct cache_entry *ce = cache_dir_exists(dirname, len); unsigned char endchar; if (!ce) diff --git a/name-hash.c b/name-hash.c index 5b01554..2bae75d 100644 --- a/name-hash.c +++ b/name-hash.c @@ -58,9 +58,9 @@ static struct dir_entry *hash_dir_entry(struct index_state *istate, { /* * Throw each directory component in the hash for quick lookup - * during a git status. Directory components are stored with their + * during a git status. Directory components are stored without their * closing slash. Despite submodules being a directory, they never - * reach this point, because they are stored without a closing slash + * reach this point, because they are stored * in index_state.name_hash (as ordinary cache_entries). * * Note that the cache_entry stored with the dir_entry merely @@ -78,6 +78,7 @@ static struct dir_entry *hash_dir_entry(struct index_state *istate, namelen--; if (namelen <= 0) return NULL; + namelen--; /* lookup existing entry for that directory */ dir = find_dir_entry(istate, ce->name, namelen); @@ -97,7 +98,7 @@ static struct dir_entry *hash_dir_entry(struct index_state *istate, } /* recursively add missing parent directories */ - dir->parent = hash_dir_entry(istate, ce, namelen - 1); + dir->parent = hash_dir_entry(istate, ce, namelen); } return dir; } @@ -237,7 +238,7 @@ struct cache_entry *index_dir_exists(struct index_state *istate, const char *nam * in the dir-hash, submodules are stored in the name-hash, so check * there, as well. */ - ce = index_name_exists(istate, name, namelen - 1, 1); + ce = index_name_exists(istate, name, namelen, 1); if (ce && S_ISGITLINK(ce->ce_mode)) return ce; diff --git a/read-cache.c b/read-cache.c index a59644a..8990b61 100644 --- a/read-cache.c +++ b/read-cache.c @@ -643,7 +643,7 @@ int add_to_index(struct index_state *istate, const char *path, struct stat *st, if (*ptr == '/') { struct cache_entry *foundce; ++ptr; - foundce = index_dir_exists(istate, ce->name, ptr - ce->name); + foundce = index_dir_exists(istate, ce->name, ptr - ce->name - 1); if (foundce) { memcpy((void *)startPtr, foundce->name + (startPtr - ce->name), ptr - startPtr); startPtr = ptr;
-- 1.8.4.457.g424cb08