avoid pointer arithmetic involving NULL in FLEX_ALLOC_MEM

diff --git a/sha1_file.c b/sha1_file.c
index 2c68766ebf0cab5f13f684ac3e26061b93bda44a..ab16c7b98cbd72bc79e8c0866417889626e2e71a 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -36,6 +36,7 @@
 static inline uintmax_t sz_fmt(size_t s) { return s; }
 
 const unsigned char null_sha1[20];
+const struct object_id null_oid;
 
 /*
  * This is meant to hold a *small* number of objects that you would
@@ -252,7 +253,7 @@ static int link_alt_odb_entry(const char *entry, const char *relative_base,
 {
        struct alternate_object_database *ent;
        struct alternate_object_database *alt;
-       int pfxlen, entlen;
+       size_t pfxlen, entlen;
        struct strbuf pathbuf = STRBUF_INIT;
 
        if (!is_absolute_path(entry) && relative_base) {
@@ -272,8 +273,8 @@ static int link_alt_odb_entry(const char *entry, const char *relative_base,
        while (pfxlen && pathbuf.buf[pfxlen-1] == '/')
                pfxlen -= 1;
 
-       entlen = pfxlen + 43; /* '/' + 2 hex + '/' + 38 hex + NUL */
-       ent = xmalloc(sizeof(*ent) + entlen);
+       entlen = st_add(pfxlen, 43); /* '/' + 2 hex + '/' + 38 hex + NUL */
+       ent = xmalloc(st_add(sizeof(*ent), entlen));
        memcpy(ent->base, pathbuf.buf, pfxlen);
        strbuf_release(&pathbuf);
 
@@ -1133,7 +1134,7 @@ unsigned char *use_pack(struct packed_git *p,
 
 static struct packed_git *alloc_packed_git(int extra)
 {
-       struct packed_git *p = xmalloc(sizeof(*p) + extra);
+       struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
        memset(p, 0, sizeof(*p));
        p->pack_fd = -1;
        return p;
@@ -1167,7 +1168,7 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
         * ".pack" is long enough to hold any suffix we're adding (and
         * the use xsnprintf double-checks that)
         */
-       alloc = path_len + strlen(".pack") + 1;
+       alloc = st_add3(path_len, strlen(".pack"), 1);
        p = alloc_packed_git(alloc);
        memcpy(p->pack_name, path, path_len);
 
@@ -1195,7 +1196,7 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
 {
        const char *path = sha1_pack_name(sha1);
-       int alloc = strlen(path) + 1;
+       size_t alloc = st_add(strlen(path), 1);
        struct packed_git *p = alloc_packed_git(alloc);
 
        memcpy(p->pack_name, path, alloc); /* includes NUL */
@@ -1412,10 +1413,12 @@ static void mark_bad_packed_object(struct packed_git *p,
 {
        unsigned i;
        for (i = 0; i < p->num_bad_objects; i++)
-               if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
+               if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
                        return;
-       p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
-       hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
+       p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
+                                     st_mult(GIT_SHA1_RAWSZ,
+                                             st_add(p->num_bad_objects, 1)));
+       hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
        p->num_bad_objects++;
 }
 
@@ -1941,7 +1944,7 @@ static enum object_type packed_to_object_type(struct packed_git *p,
                /* Push the object we're going to leave behind */
                if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
                        poi_stack_alloc = alloc_nr(poi_stack_nr);
-                       poi_stack = xmalloc(sizeof(off_t)*poi_stack_alloc);
+                       ALLOC_ARRAY(poi_stack, poi_stack_alloc);
                        memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
                } else {
                        ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
@@ -2307,7 +2310,7 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
                if (delta_stack_nr >= delta_stack_alloc
                    && delta_stack == small_delta_stack) {
                        delta_stack_alloc = alloc_nr(delta_stack_nr);
-                       delta_stack = xmalloc(sizeof(*delta_stack)*delta_stack_alloc);
+                       ALLOC_ARRAY(delta_stack, delta_stack_alloc);
                        memcpy(delta_stack, small_delta_stack,
                               sizeof(*delta_stack)*delta_stack_nr);
                } else {