Git 2.7.6
[gitweb.git] / sha1_file.c
index 2350a91dbe5dc9e895e3e688e546ff83307ad6dc..b516874473e2d800d1bbad6e50fda4532bc9aae0 100644 (file)
@@ -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
@@ -208,44 +209,25 @@ const char *sha1_file_name(const unsigned char *sha1)
  * provided by the caller.  which should be "pack" or "idx".
  */
 static char *sha1_get_pack_name(const unsigned char *sha1,
-                               char **name, char **base, const char *which)
+                               struct strbuf *buf,
+                               const char *which)
 {
-       static const char hex[] = "0123456789abcdef";
-       char *buf;
-       int i;
-
-       if (!*base) {
-               const char *sha1_file_directory = get_object_directory();
-               int len = strlen(sha1_file_directory);
-               *base = xmalloc(len + 60);
-               sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
-                       sha1_file_directory, which);
-               *name = *base + len + 11;
-       }
-
-       buf = *name;
-
-       for (i = 0; i < 20; i++) {
-               unsigned int val = *sha1++;
-               *buf++ = hex[val >> 4];
-               *buf++ = hex[val & 0xf];
-       }
-
-       return *base;
+       strbuf_reset(buf);
+       strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
+                   sha1_to_hex(sha1), which);
+       return buf->buf;
 }
 
 char *sha1_pack_name(const unsigned char *sha1)
 {
-       static char *name, *base;
-
-       return sha1_get_pack_name(sha1, &name, &base, "pack");
+       static struct strbuf buf = STRBUF_INIT;
+       return sha1_get_pack_name(sha1, &buf, "pack");
 }
 
 char *sha1_pack_index_name(const unsigned char *sha1)
 {
-       static char *name, *base;
-
-       return sha1_get_pack_name(sha1, &name, &base, "idx");
+       static struct strbuf buf = STRBUF_INIT;
+       return sha1_get_pack_name(sha1, &buf, "idx");
 }
 
 struct alternate_object_database *alt_odb_list;
@@ -271,7 +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) {
@@ -291,8 +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);
 
@@ -401,13 +383,46 @@ void read_info_alternates(const char * relative_base, int depth)
 void add_to_alternates_file(const char *reference)
 {
        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
-       int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
-       char *alt = mkpath("%s\n", reference);
-       write_or_die(fd, alt, strlen(alt));
-       if (commit_lock_file(lock))
-               die("could not close alternates file");
-       if (alt_odb_tail)
-               link_alt_odb_entries(alt, strlen(alt), '\n', NULL, 0);
+       char *alts = git_pathdup("objects/info/alternates");
+       FILE *in, *out;
+
+       hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR);
+       out = fdopen_lock_file(lock, "w");
+       if (!out)
+               die_errno("unable to fdopen alternates lockfile");
+
+       in = fopen(alts, "r");
+       if (in) {
+               struct strbuf line = STRBUF_INIT;
+               int found = 0;
+
+               while (strbuf_getline(&line, in, '\n') != EOF) {
+                       if (!strcmp(reference, line.buf)) {
+                               found = 1;
+                               break;
+                       }
+                       fprintf_or_die(out, "%s\n", line.buf);
+               }
+
+               strbuf_release(&line);
+               fclose(in);
+
+               if (found) {
+                       rollback_lock_file(lock);
+                       lock = NULL;
+               }
+       }
+       else if (errno != ENOENT)
+               die_errno("unable to read alternates file");
+
+       if (lock) {
+               fprintf_or_die(out, "%s\n", reference);
+               if (commit_lock_file(lock))
+                       die_errno("unable to move new alternates file into place");
+               if (alt_odb_tail)
+                       link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
+       }
+       free(alts);
 }
 
 int foreach_alt_odb(alt_odb_fn fn, void *cb)
@@ -440,6 +455,7 @@ void prepare_alt_odb(void)
        read_info_alternates(get_object_directory(), 0);
 }
 
+/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
 static int freshen_file(const char *fn)
 {
        struct utimbuf t;
@@ -447,11 +463,18 @@ static int freshen_file(const char *fn)
        return !utime(fn, &t);
 }
 
+/*
+ * All of the check_and_freshen functions return 1 if the file exists and was
+ * freshened (if freshening was requested), 0 otherwise. If they return
+ * 0, you should not assume that it is safe to skip a write of the object (it
+ * either does not exist on disk, or has a stale mtime and may be subject to
+ * pruning).
+ */
 static int check_and_freshen_file(const char *fn, int freshen)
 {
        if (access(fn, F_OK))
                return 0;
-       if (freshen && freshen_file(fn))
+       if (freshen && !freshen_file(fn))
                return 0;
        return 1;
 }
@@ -630,13 +653,15 @@ static int check_packed_git_idx(const char *path, struct packed_git *p)
 int open_pack_index(struct packed_git *p)
 {
        char *idx_name;
+       size_t len;
        int ret;
 
        if (p->index_data)
                return 0;
 
-       idx_name = xstrdup(p->pack_name);
-       strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
+       if (!strip_suffix(p->pack_name, ".pack", &len))
+               die("BUG: pack_name does not end in .pack");
+       idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
        ret = check_packed_git_idx(idx_name, p);
        free(idx_name);
        return ret;
@@ -704,8 +729,8 @@ static void mmap_limit_check(size_t length)
                    (uintmax_t)length, (uintmax_t)limit);
 }
 
-void *xmmap(void *start, size_t length,
-       int prot, int flags, int fd, off_t offset)
+void *xmmap_gently(void *start, size_t length,
+                 int prot, int flags, int fd, off_t offset)
 {
        void *ret;
 
@@ -716,12 +741,19 @@ void *xmmap(void *start, size_t length,
                        return NULL;
                release_pack_memory(length);
                ret = mmap(start, length, prot, flags, fd, offset);
-               if (ret == MAP_FAILED)
-                       die_errno("Out of memory? mmap failed");
        }
        return ret;
 }
 
+void *xmmap(void *start, size_t length,
+       int prot, int flags, int fd, off_t offset)
+{
+       void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
+       if (ret == MAP_FAILED)
+               die_errno("mmap failed");
+       return ret;
+}
+
 void close_pack_windows(struct packed_git *p)
 {
        while (p->windows) {
@@ -738,6 +770,37 @@ void close_pack_windows(struct packed_git *p)
        }
 }
 
+static int close_pack_fd(struct packed_git *p)
+{
+       if (p->pack_fd < 0)
+               return 0;
+
+       close(p->pack_fd);
+       pack_open_fds--;
+       p->pack_fd = -1;
+
+       return 1;
+}
+
+static void close_pack(struct packed_git *p)
+{
+       close_pack_windows(p);
+       close_pack_fd(p);
+       close_pack_index(p);
+}
+
+void close_all_packs(void)
+{
+       struct packed_git *p;
+
+       for (p = packed_git; p; p = p->next)
+               if (p->do_not_close)
+                       die("BUG! Want to close pack marked 'do-not-close'");
+               else
+                       close_pack(p);
+}
+
+
 /*
  * The LRU pack is the one with the oldest MRU window, preferring packs
  * with no used windows, or the oldest mtime if it has no windows allocated.
@@ -805,12 +868,8 @@ static int close_one_pack(void)
                find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
        }
 
-       if (lru_p) {
-               close(lru_p->pack_fd);
-               pack_open_fds--;
-               lru_p->pack_fd = -1;
-               return 1;
-       }
+       if (lru_p)
+               return close_pack_fd(lru_p);
 
        return 0;
 }
@@ -850,12 +909,7 @@ void free_pack_by_name(const char *pack_name)
                p = *pp;
                if (strcmp(pack_name, p->pack_name) == 0) {
                        clear_delta_base_cache();
-                       close_pack_windows(p);
-                       if (p->pack_fd != -1) {
-                               close(p->pack_fd);
-                               pack_open_fds--;
-                       }
-                       close_pack_index(p);
+                       close_pack(p);
                        free(p->bad_object_sha1);
                        *pp = p->next;
                        if (last_found_pack == p)
@@ -989,11 +1043,7 @@ static int open_packed_git(struct packed_git *p)
 {
        if (!open_packed_git_1(p))
                return 0;
-       if (p->pack_fd != -1) {
-               close(p->pack_fd);
-               pack_open_fds--;
-               p->pack_fd = -1;
-       }
+       close_pack_fd(p);
        return -1;
 }
 
@@ -1026,6 +1076,8 @@ unsigned char *use_pack(struct packed_git *p,
                die("packfile %s cannot be accessed", p->pack_name);
        if (offset > (p->pack_size - 20))
                die("offset beyond end of packfile (truncated pack?)");
+       if (offset < 0)
+               die(_("offset before end of packfile (broken .idx?)"));
 
        if (!win || !in_window(win, offset)) {
                if (win)
@@ -1059,11 +1111,8 @@ unsigned char *use_pack(struct packed_git *p,
                                        p->pack_name,
                                        strerror(errno));
                        if (!win->offset && win->len == p->pack_size
-                               && !p->do_not_close) {
-                               close(p->pack_fd);
-                               pack_open_fds--;
-                               p->pack_fd = -1;
-                       }
+                               && !p->do_not_close)
+                               close_pack_fd(p);
                        pack_mmap_calls++;
                        pack_open_windows++;
                        if (pack_mapped > peak_pack_mapped)
@@ -1087,7 +1136,7 @@ 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;
@@ -1098,11 +1147,12 @@ 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;
@@ -1113,18 +1163,22 @@ 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 = st_add3(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;
@@ -1144,9 +1198,10 @@ struct packed_git *add_packed_git(const char *path, int path_len, int local)
 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
 {
        const char *path = sha1_pack_name(sha1);
-       struct packed_git *p = alloc_packed_git(strlen(path) + 1);
+       size_t alloc = st_add(strlen(path), 1);
+       struct packed_git *p = alloc_packed_git(alloc);
 
-       strcpy(p->pack_name, path);
+       memcpy(p->pack_name, path, alloc); /* includes NUL */
        hashcpy(p->sha1, sha1);
        if (check_packed_git_idx(idx_path, p)) {
                free(p);
@@ -1165,27 +1220,16 @@ void install_packed_git(struct packed_git *pack)
        packed_git = pack;
 }
 
-void (*report_garbage)(const char *desc, const char *path);
+void (*report_garbage)(unsigned seen_bits, const char *path);
 
 static void report_helper(const struct string_list *list,
                          int seen_bits, int first, int last)
 {
-       const char *msg;
-       switch (seen_bits) {
-       case 0:
-               msg = "no corresponding .idx or .pack";
-               break;
-       case 1:
-               msg = "no corresponding .idx";
-               break;
-       case 2:
-               msg = "no corresponding .pack";
-               break;
-       default:
+       if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
                return;
-       }
+
        for (; first < last; first++)
-               report_garbage(msg, list->items[first].string);
+               report_garbage(seen_bits, list->items[first].string);
 }
 
 static void report_pack_garbage(struct string_list *list)
@@ -1195,7 +1239,7 @@ static void report_pack_garbage(struct string_list *list)
        if (!report_garbage)
                return;
 
-       sort_string_list(list);
+       string_list_sort(list);
 
        for (i = 0; i < list->nr; i++) {
                const char *path = list->items[i].string;
@@ -1208,7 +1252,7 @@ static void report_pack_garbage(struct string_list *list)
                if (baselen == -1) {
                        const char *dot = strrchr(path, '.');
                        if (!dot) {
-                               report_garbage("garbage found", path);
+                               report_garbage(PACKDIR_FILE_GARBAGE, path);
                                continue;
                        }
                        baselen = dot - path + 1;
@@ -1280,7 +1324,7 @@ static void prepare_packed_git_one(char *objdir, int local)
                    ends_with(de->d_name, ".keep"))
                        string_list_append(&garbage, path.buf);
                else
-                       report_garbage("garbage found", path.buf);
+                       report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
        }
        closedir(dir);
        report_pack_garbage(&garbage);
@@ -1371,10 +1415,12 @@ 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++;
 }
 
@@ -1416,7 +1462,7 @@ int check_sha1_signature(const unsigned char *sha1, void *map,
                return -1;
 
        /* Generate the header */
-       hdrlen = sprintf(hdr, "%s %lu", typename(obj_type), size) + 1;
+       hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1;
 
        /* Sha1.. */
        git_SHA1_Init(&c);
@@ -1443,7 +1489,10 @@ int git_open_noatime(const char *name)
        static int sha1_file_open_flag = O_NOATIME;
 
        for (;;) {
-               int fd = open(name, O_RDONLY | sha1_file_open_flag);
+               int fd;
+
+               errno = 0;
+               fd = open(name, O_RDONLY | sha1_file_open_flag);
                if (fd >= 0)
                        return fd;
 
@@ -1561,6 +1610,40 @@ int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long ma
        return git_inflate(stream, 0);
 }
 
+static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
+                                       unsigned long mapsize, void *buffer,
+                                       unsigned long bufsiz, struct strbuf *header)
+{
+       int status;
+
+       status = unpack_sha1_header(stream, map, mapsize, buffer, bufsiz);
+
+       /*
+        * Check if entire header is unpacked in the first iteration.
+        */
+       if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
+               return 0;
+
+       /*
+        * buffer[0..bufsiz] was not large enough.  Copy the partial
+        * result out to header, and then append the result of further
+        * reading the stream.
+        */
+       strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
+       stream->next_out = buffer;
+       stream->avail_out = bufsiz;
+
+       do {
+               status = git_inflate(stream, 0);
+               strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
+               if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
+                       return 0;
+               stream->next_out = buffer;
+               stream->avail_out = bufsiz;
+       } while (status != Z_STREAM_END);
+       return -1;
+}
+
 static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
 {
        int bytes = strlen(buffer) + 1;
@@ -1611,27 +1694,38 @@ static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long s
  * too permissive for what we want to check. So do an anal
  * object header parse by hand.
  */
-int parse_sha1_header(const char *hdr, unsigned long *sizep)
+static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
+                              unsigned int flags)
 {
-       char type[10];
-       int i;
+       const char *type_buf = hdr;
        unsigned long size;
+       int type, type_len = 0;
 
        /*
-        * The type can be at most ten bytes (including the
-        * terminating '\0' that we add), and is followed by
+        * The type can be of any size but is followed by
         * a space.
         */
-       i = 0;
        for (;;) {
                char c = *hdr++;
                if (c == ' ')
                        break;
-               type[i++] = c;
-               if (i >= sizeof(type))
-                       return -1;
+               type_len++;
        }
-       type[i] = 0;
+
+       type = type_from_string_gently(type_buf, type_len, 1);
+       if (oi->typename)
+               strbuf_add(oi->typename, type_buf, type_len);
+       /*
+        * Set type to 0 if its an unknown object and
+        * we're obtaining the type using '--allow-unkown-type'
+        * option.
+        */
+       if ((flags & LOOKUP_UNKNOWN_OBJECT) && (type < 0))
+               type = 0;
+       else if (type < 0)
+               die("invalid object type");
+       if (oi->typep)
+               *oi->typep = type;
 
        /*
         * The length must follow immediately, and be in canonical
@@ -1649,12 +1743,24 @@ int parse_sha1_header(const char *hdr, unsigned long *sizep)
                        size = size * 10 + c;
                }
        }
-       *sizep = size;
+
+       if (oi->sizep)
+               *oi->sizep = size;
 
        /*
         * The length must be followed by a zero byte
         */
-       return *hdr ? -1 : type_from_string(type);
+       return *hdr ? -1 : type;
+}
+
+int parse_sha1_header(const char *hdr, unsigned long *sizep)
+{
+       struct object_info oi;
+
+       oi.sizep = sizep;
+       oi.typename = NULL;
+       oi.typep = NULL;
+       return parse_sha1_header_extended(hdr, &oi, LOOKUP_REPLACE_OBJECT);
 }
 
 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
@@ -1840,7 +1946,7 @@ 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);
@@ -2206,7 +2312,7 @@ 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 {
@@ -2344,6 +2450,20 @@ const unsigned char *nth_packed_object_sha1(struct packed_git *p,
        }
 }
 
+void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
+{
+       const unsigned char *ptr = vptr;
+       const unsigned char *start = p->index_data;
+       const unsigned char *end = start + p->index_size;
+       if (ptr < start)
+               die(_("offset before start of pack index for %s (corrupt index?)"),
+                   p->pack_name);
+       /* No need to check for underflow; .idx files must be at least 8 bytes */
+       if (ptr >= end - 8)
+               die(_("offset beyond end of pack index for %s (truncated index?)"),
+                   p->pack_name);
+}
+
 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
 {
        const unsigned char *index = p->index_data;
@@ -2357,6 +2477,7 @@ off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
                if (!(off & 0x80000000))
                        return off;
                index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
+               check_pack_index_ptr(p, index);
                return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
                                   ntohl(*((uint32_t *)(index + 4)));
        }
@@ -2470,10 +2591,8 @@ static int fill_pack_entry(const unsigned char *sha1,
         * answer, as it may have been deleted since the index was
         * loaded!
         */
-       if (!is_pack_valid(p)) {
-               warning("packfile %s cannot be accessed", p->pack_name);
+       if (!is_pack_valid(p))
                return 0;
-       }
        e->offset = offset;
        e->p = p;
        hashcpy(e->sha1, sha1);
@@ -2521,13 +2640,15 @@ struct packed_git *find_sha1_pack(const unsigned char *sha1,
 }
 
 static int sha1_loose_object_info(const unsigned char *sha1,
-                                 struct object_info *oi)
+                                 struct object_info *oi,
+                                 int flags)
 {
-       int status;
-       unsigned long mapsize, size;
+       int status = 0;
+       unsigned long mapsize;
        void *map;
        git_zstream stream;
        char hdr[32];
+       struct strbuf hdrbuf = STRBUF_INIT;
 
        if (oi->delta_base_sha1)
                hashclr(oi->delta_base_sha1);
@@ -2540,7 +2661,7 @@ static int sha1_loose_object_info(const unsigned char *sha1,
         * return value implicitly indicates whether the
         * object even exists.
         */
-       if (!oi->typep && !oi->sizep) {
+       if (!oi->typep && !oi->typename && !oi->sizep) {
                struct stat st;
                if (stat_sha1_file(sha1, &st) < 0)
                        return -1;
@@ -2554,17 +2675,26 @@ static int sha1_loose_object_info(const unsigned char *sha1,
                return -1;
        if (oi->disk_sizep)
                *oi->disk_sizep = mapsize;
-       if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
+       if ((flags & LOOKUP_UNKNOWN_OBJECT)) {
+               if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
+                       status = error("unable to unpack %s header with --allow-unknown-type",
+                                      sha1_to_hex(sha1));
+       } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
                status = error("unable to unpack %s header",
                               sha1_to_hex(sha1));
-       else if ((status = parse_sha1_header(hdr, &size)) < 0)
+       if (status < 0)
+               ; /* Do nothing */
+       else if (hdrbuf.len) {
+               if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
+                       status = error("unable to parse %s header with --allow-unknown-type",
+                                      sha1_to_hex(sha1));
+       } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
                status = error("unable to parse %s header", sha1_to_hex(sha1));
-       else if (oi->sizep)
-               *oi->sizep = size;
        git_inflate_end(&stream);
        munmap(map, mapsize);
-       if (oi->typep)
+       if (status && oi->typep)
                *oi->typep = status;
+       strbuf_release(&hdrbuf);
        return 0;
 }
 
@@ -2573,6 +2703,7 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
        struct cached_object *co;
        struct pack_entry e;
        int rtype;
+       enum object_type real_type;
        const unsigned char *real = lookup_replace_object_extended(sha1, flags);
 
        co = find_cached_object(real);
@@ -2585,13 +2716,15 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
                        *(oi->disk_sizep) = 0;
                if (oi->delta_base_sha1)
                        hashclr(oi->delta_base_sha1);
+               if (oi->typename)
+                       strbuf_addstr(oi->typename, typename(co->type));
                oi->whence = OI_CACHED;
                return 0;
        }
 
        if (!find_pack_entry(real, &e)) {
                /* Most likely it's a loose object. */
-               if (!sha1_loose_object_info(real, oi)) {
+               if (!sha1_loose_object_info(real, oi, flags)) {
                        oi->whence = OI_LOOSE;
                        return 0;
                }
@@ -2602,9 +2735,18 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
                        return -1;
        }
 
+       /*
+        * packed_object_info() does not follow the delta chain to
+        * find out the real type, unless it is given oi->typep.
+        */
+       if (oi->typename && !oi->typep)
+               oi->typep = &real_type;
+
        rtype = packed_object_info(e.p, e.offset, oi);
        if (rtype < 0) {
                mark_bad_packed_object(e.p, real);
+               if (oi->typep == &real_type)
+                       oi->typep = NULL;
                return sha1_object_info_extended(real, oi, 0);
        } else if (in_delta_base_cache(e.p, e.offset)) {
                oi->whence = OI_DBCACHED;
@@ -2615,6 +2757,10 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
                oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
                                         rtype == OBJ_OFS_DELTA);
        }
+       if (oi->typename)
+               strbuf_addstr(oi->typename, typename(*oi->typep));
+       if (oi->typep == &real_type)
+               oi->typep = NULL;
 
        return 0;
 }
@@ -2797,7 +2943,7 @@ static void write_sha1_file_prepare(const void *buf, unsigned long len,
        git_SHA_CTX c;
 
        /* Generate the header */
-       *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
+       *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
 
        /* Sha1.. */
        git_SHA1_Init(&c);
@@ -2808,11 +2954,8 @@ static void write_sha1_file_prepare(const void *buf, unsigned long len,
 
 /*
  * Move the just written object into its final resting place.
- * NEEDSWORK: this should be renamed to finalize_temp_file() as
- * "moving" is only a part of what it does, when no patch between
- * master to pu changes the call sites of this function.
  */
-int move_temp_to_file(const char *tmpfile, const char *filename)
+int finalize_object_file(const char *tmpfile, const char *filename)
 {
        int ret = 0;
 
@@ -2863,7 +3006,7 @@ int hash_sha1_file(const void *buf, unsigned long len, const char *type,
                    unsigned char *sha1)
 {
        char hdr[32];
-       int hdrlen;
+       int hdrlen = sizeof(hdr);
        write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
        return 0;
 }
@@ -2893,29 +3036,31 @@ static inline int directory_size(const char *filename)
  * We want to avoid cross-directory filename renames, because those
  * can have problems on various filesystems (FAT, NFS, Coda).
  */
-static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
+static int create_tmpfile(struct strbuf *tmp, const char *filename)
 {
        int fd, dirlen = directory_size(filename);
 
-       if (dirlen + 20 > bufsiz) {
-               errno = ENAMETOOLONG;
-               return -1;
-       }
-       memcpy(buffer, filename, dirlen);
-       strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
-       fd = git_mkstemp_mode(buffer, 0444);
+       strbuf_reset(tmp);
+       strbuf_add(tmp, filename, dirlen);
+       strbuf_addstr(tmp, "tmp_obj_XXXXXX");
+       fd = git_mkstemp_mode(tmp->buf, 0444);
        if (fd < 0 && dirlen && errno == ENOENT) {
-               /* Make sure the directory exists */
-               memcpy(buffer, filename, dirlen);
-               buffer[dirlen-1] = 0;
-               if (mkdir(buffer, 0777) && errno != EEXIST)
+               /*
+                * Make sure the directory exists; note that the contents
+                * of the buffer are undefined after mkstemp returns an
+                * error, so we have to rewrite the whole buffer from
+                * scratch.
+                */
+               strbuf_reset(tmp);
+               strbuf_add(tmp, filename, dirlen - 1);
+               if (mkdir(tmp->buf, 0777) && errno != EEXIST)
                        return -1;
-               if (adjust_shared_perm(buffer))
+               if (adjust_shared_perm(tmp->buf))
                        return -1;
 
                /* Try again */
-               strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
-               fd = git_mkstemp_mode(buffer, 0444);
+               strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
+               fd = git_mkstemp_mode(tmp->buf, 0444);
        }
        return fd;
 }
@@ -2928,10 +3073,10 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
        git_zstream stream;
        git_SHA_CTX c;
        unsigned char parano_sha1[20];
-       static char tmp_file[PATH_MAX];
+       static struct strbuf tmp_file = STRBUF_INIT;
        const char *filename = sha1_file_name(sha1);
 
-       fd = create_tmpfile(tmp_file, sizeof(tmp_file), filename);
+       fd = create_tmpfile(&tmp_file, filename);
        if (fd < 0) {
                if (errno == EACCES)
                        return error("insufficient permission for adding an object to repository database %s", get_object_directory());
@@ -2940,7 +3085,6 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
        }
 
        /* Set it up */
-       memset(&stream, 0, sizeof(stream));
        git_deflate_init(&stream, zlib_compression_level);
        stream.next_out = compressed;
        stream.avail_out = sizeof(compressed);
@@ -2981,12 +3125,12 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
                struct utimbuf utb;
                utb.actime = mtime;
                utb.modtime = mtime;
-               if (utime(tmp_file, &utb) < 0)
+               if (utime(tmp_file.buf, &utb) < 0)
                        warning("failed utime() on %s: %s",
-                               tmp_file, strerror(errno));
+                               tmp_file.buf, strerror(errno));
        }
 
-       return move_temp_to_file(tmp_file, filename);
+       return finalize_object_file(tmp_file.buf, filename);
 }
 
 static int freshen_loose_object(const unsigned char *sha1)
@@ -2997,26 +3141,52 @@ static int freshen_loose_object(const unsigned char *sha1)
 static int freshen_packed_object(const unsigned char *sha1)
 {
        struct pack_entry e;
-       return find_pack_entry(sha1, &e) && freshen_file(e.p->pack_name);
+       if (!find_pack_entry(sha1, &e))
+               return 0;
+       if (e.p->freshened)
+               return 1;
+       if (!freshen_file(e.p->pack_name))
+               return 0;
+       e.p->freshened = 1;
+       return 1;
 }
 
-int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
+int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
 {
-       unsigned char sha1[20];
        char hdr[32];
-       int hdrlen;
+       int hdrlen = sizeof(hdr);
 
        /* Normally if we have it in the pack then we do not bother writing
         * it out into .git/objects/??/?{38} file.
         */
        write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
-       if (returnsha1)
-               hashcpy(returnsha1, sha1);
-       if (freshen_loose_object(sha1) || freshen_packed_object(sha1))
+       if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
                return 0;
        return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
 }
 
+int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
+                            unsigned char *sha1, unsigned flags)
+{
+       char *header;
+       int hdrlen, status = 0;
+
+       /* type string, SP, %lu of the length plus NUL must fit this */
+       hdrlen = strlen(type) + 32;
+       header = xmalloc(hdrlen);
+       write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
+
+       if (!(flags & HASH_WRITE_OBJECT))
+               goto cleanup;
+       if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
+               goto cleanup;
+       status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
+
+cleanup:
+       free(header);
+       return status;
+}
+
 int force_object_loose(const unsigned char *sha1, time_t mtime)
 {
        void *buf;
@@ -3031,7 +3201,7 @@ int force_object_loose(const unsigned char *sha1, time_t mtime)
        buf = read_packed_sha1(sha1, &type, &len);
        if (!buf)
                return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
-       hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
+       hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), len) + 1;
        ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
        free(buf);
 
@@ -3052,7 +3222,7 @@ int has_sha1_pack(const unsigned char *sha1)
        return find_pack_entry(sha1, &e);
 }
 
-int has_sha1_file(const unsigned char *sha1)
+int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
 {
        struct pack_entry e;
 
@@ -3060,10 +3230,17 @@ int has_sha1_file(const unsigned char *sha1)
                return 1;
        if (has_loose_object(sha1))
                return 1;
+       if (flags & HAS_SHA1_QUICK)
+               return 0;
        reprepare_packed_git();
        return find_pack_entry(sha1, &e);
 }
 
+int has_object_file(const struct object_id *oid)
+{
+       return has_sha1_file(oid->hash);
+}
+
 static void check_tree(const void *buf, size_t size)
 {
        struct tree_desc desc;
@@ -3177,7 +3354,7 @@ static int index_core(unsigned char *sha1, int fd, size_t size,
        int ret;
 
        if (!size) {
-               ret = index_mem(sha1, NULL, size, type, path, flags);
+               ret = index_mem(sha1, "", size, type, path, flags);
        } else if (size <= SMALL_FILE_SIZE) {
                char *buf = xmalloc(size);
                if (size == read_in_full(fd, buf, size))
@@ -3347,40 +3524,51 @@ static int for_each_file_in_obj_subdir(int subdir_nr,
                                break;
                }
        }
-       strbuf_setlen(path, baselen);
+       closedir(dir);
 
+       strbuf_setlen(path, baselen);
        if (!r && subdir_cb)
                r = subdir_cb(subdir_nr, path->buf, data);
 
-       closedir(dir);
        return r;
 }
 
-int for_each_loose_file_in_objdir(const char *path,
+int for_each_loose_file_in_objdir_buf(struct strbuf *path,
                            each_loose_object_fn obj_cb,
                            each_loose_cruft_fn cruft_cb,
                            each_loose_subdir_fn subdir_cb,
                            void *data)
 {
-       struct strbuf buf = STRBUF_INIT;
-       size_t baselen;
+       size_t baselen = path->len;
        int r = 0;
        int i;
 
-       strbuf_addstr(&buf, path);
-       strbuf_addch(&buf, '/');
-       baselen = buf.len;
-
        for (i = 0; i < 256; i++) {
-               strbuf_addf(&buf, "%02x", i);
-               r = for_each_file_in_obj_subdir(i, &buf, obj_cb, cruft_cb,
+               strbuf_addf(path, "/%02x", i);
+               r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
                                                subdir_cb, data);
-               strbuf_setlen(&buf, baselen);
+               strbuf_setlen(path, baselen);
                if (r)
                        break;
        }
 
+       return r;
+}
+
+int for_each_loose_file_in_objdir(const char *path,
+                                 each_loose_object_fn obj_cb,
+                                 each_loose_cruft_fn cruft_cb,
+                                 each_loose_subdir_fn subdir_cb,
+                                 void *data)
+{
+       struct strbuf buf = STRBUF_INIT;
+       int r;
+
+       strbuf_addstr(&buf, path);
+       r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
+                                             subdir_cb, data);
        strbuf_release(&buf);
+
        return r;
 }
 
@@ -3393,12 +3581,19 @@ static int loose_from_alt_odb(struct alternate_object_database *alt,
                              void *vdata)
 {
        struct loose_alt_odb_data *data = vdata;
-       return for_each_loose_file_in_objdir(alt->base,
-                                            data->cb, NULL, NULL,
-                                            data->data);
+       struct strbuf buf = STRBUF_INIT;
+       int r;
+
+       /* copy base not including trailing '/' */
+       strbuf_add(&buf, alt->base, alt->name - alt->base - 1);
+       r = for_each_loose_file_in_objdir_buf(&buf,
+                                             data->cb, NULL, NULL,
+                                             data->data);
+       strbuf_release(&buf);
+       return r;
 }
 
-int for_each_loose_object(each_loose_object_fn cb, void *data)
+int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
 {
        struct loose_alt_odb_data alt;
        int r;
@@ -3408,6 +3603,9 @@ int for_each_loose_object(each_loose_object_fn cb, void *data)
        if (r)
                return r;
 
+       if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
+               return 0;
+
        alt.cb = cb;
        alt.data = data;
        return foreach_alt_odb(loose_from_alt_odb, &alt);
@@ -3432,16 +3630,23 @@ static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn c
        return r;
 }
 
-int for_each_packed_object(each_packed_object_fn cb, void *data)
+int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
 {
        struct packed_git *p;
        int r = 0;
+       int pack_errors = 0;
 
        prepare_packed_git();
        for (p = packed_git; p; p = p->next) {
+               if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
+                       continue;
+               if (open_pack_index(p)) {
+                       pack_errors = 1;
+                       continue;
+               }
                r = for_each_object_in_pack(p, cb, data);
                if (r)
                        break;
        }
-       return r;
+       return r ? r : pack_errors;
 }