add_packed_git: convert strcpy into xsnprintf

We have the path "foo.idx", and we create a buffer big
enough to hold "foo.pack" and "foo.keep", and then strcpy
straight into it. This isn't a bug (we have enough space),
but it's very hard to tell from the strcpy that this is so.

Let's instead use strip_suffix to take off the ".idx",
record the size of our allocation, and use xsnprintf to make
sure we don't violate our assumptions.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King 2015-09-24 17:06:55 -04:00 коммит произвёл Junio C Hamano
Родитель 330c8e2670
Коммит 48bcc1c3cc
2 изменённых файлов: 14 добавлений и 9 удалений

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@ -1309,7 +1309,7 @@ extern void close_pack_windows(struct packed_git *);
extern void unuse_pack(struct pack_window **);
extern void free_pack_by_name(const char *);
extern void clear_delta_base_cache(void);
extern struct packed_git *add_packed_git(const char *, int, int);
extern struct packed_git *add_packed_git(const char *path, size_t path_len, int local);
/*
* Return the SHA-1 of the nth object within the specified packfile.

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@ -1146,11 +1146,12 @@ static void try_to_free_pack_memory(size_t size)
release_pack_memory(size);
}
struct packed_git *add_packed_git(const char *path, int path_len, int local)
struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
{
static int have_set_try_to_free_routine;
struct stat st;
struct packed_git *p = alloc_packed_git(path_len + 2);
size_t alloc;
struct packed_git *p;
if (!have_set_try_to_free_routine) {
have_set_try_to_free_routine = 1;
@ -1161,18 +1162,22 @@ struct packed_git *add_packed_git(const char *path, int path_len, int local)
* Make sure a corresponding .pack file exists and that
* the index looks sane.
*/
path_len -= strlen(".idx");
if (path_len < 1) {
free(p);
if (!strip_suffix_mem(path, &path_len, ".idx"))
return NULL;
}
/*
* ".pack" is long enough to hold any suffix we're adding (and
* the use xsnprintf double-checks that)
*/
alloc = path_len + strlen(".pack") + 1;
p = alloc_packed_git(alloc);
memcpy(p->pack_name, path, path_len);
strcpy(p->pack_name + path_len, ".keep");
xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
if (!access(p->pack_name, F_OK))
p->pack_keep = 1;
strcpy(p->pack_name + path_len, ".pack");
xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
free(p);
return NULL;