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>

diff --git a/cache.h b/cache.h
index 030b88025705bd035bc911e35a061f45864d114c..d206d645508a4b5467bc9ba1cf7fe8a5cdd6f8fa 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -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 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.
 
 /*
  * Return the SHA-1 of the nth object within the specified packfile.

diff --git a/sha1_file.c b/sha1_file.c
index f1060914745bb01b0a749659dcc21e5ac066afe8..592226eb7bb9e961b357b11f678773f7ac74ab6f 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1146,11 +1146,12 @@ static void try_to_free_pack_memory(size_t size)
        release_pack_memory(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;
 {
        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;
 
        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.
         */
         * 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;
                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);
 
        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;
 
        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;
        if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
                free(p);
                return NULL;