Fix parsing of @{-1}@{1}
[gitweb.git] / sha1_file.c
index 445a871db31673af20017d36ff22fd106f77f510..f08493f039fa28c90e3edc708bbcf0a527e4f659 100644 (file)
@@ -15,6 +15,7 @@
 #include "tree.h"
 #include "refs.h"
 #include "pack-revindex.h"
+#include "sha1-lookup.h"
 
 #ifndef O_NOATIME
 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
@@ -34,8 +35,6 @@ static size_t sz_fmt(size_t s) { return s; }
 
 const unsigned char null_sha1[20];
 
-static unsigned int sha1_file_open_flag = O_NOATIME;
-
 const signed char hexval_table[256] = {
         -1, -1, -1, -1, -1, -1, -1, -1,                /* 00-07 */
         -1, -1, -1, -1, -1, -1, -1, -1,                /* 08-0f */
@@ -84,19 +83,27 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
        return 0;
 }
 
+static inline int offset_1st_component(const char *path)
+{
+       if (has_dos_drive_prefix(path))
+               return 2 + (path[2] == '/');
+       return *path == '/';
+}
+
 int safe_create_leading_directories(char *path)
 {
-       char *pos = path;
+       char *pos = path + offset_1st_component(path);
        struct stat st;
 
-       if (is_absolute_path(path))
-               pos++;
-
        while (pos) {
                pos = strchr(pos, '/');
                if (!pos)
                        break;
-               *pos = 0;
+               while (*++pos == '/')
+                       ;
+               if (!*pos)
+                       break;
+               *--pos = '\0';
                if (!stat(path, &st)) {
                        /* path exists */
                        if (!S_ISDIR(st.st_mode)) {
@@ -117,7 +124,16 @@ int safe_create_leading_directories(char *path)
        return 0;
 }
 
-char * sha1_to_hex(const unsigned char *sha1)
+int safe_create_leading_directories_const(const char *path)
+{
+       /* path points to cache entries, so xstrdup before messing with it */
+       char *buf = xstrdup(path);
+       int result = safe_create_leading_directories(buf);
+       free(buf);
+       return result;
+}
+
+char *sha1_to_hex(const unsigned char *sha1)
 {
        static int bufno;
        static char hexbuffer[4][50];
@@ -175,21 +191,23 @@ char *sha1_file_name(const unsigned char *sha1)
        return base;
 }
 
-char *sha1_pack_name(const unsigned char *sha1)
+static char *sha1_get_pack_name(const unsigned char *sha1,
+                               char **name, char **base, const char *which)
 {
        static const char hex[] = "0123456789abcdef";
-       static char *name, *base, *buf;
+       char *buf;
        int i;
 
-       if (!base) {
+       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.pack", sha1_file_directory);
-               name = base + len + 11;
+               *base = xmalloc(len + 60);
+               sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
+                       sha1_file_directory, which);
+               *name = *base + len + 11;
        }
 
-       buf = name;
+       buf = *name;
 
        for (i = 0; i < 20; i++) {
                unsigned int val = *sha1++;
@@ -197,32 +215,21 @@ char *sha1_pack_name(const unsigned char *sha1)
                *buf++ = hex[val & 0xf];
        }
 
-       return base;
+       return *base;
 }
 
-char *sha1_pack_index_name(const unsigned char *sha1)
+char *sha1_pack_name(const unsigned char *sha1)
 {
-       static const char hex[] = "0123456789abcdef";
-       static char *name, *base, *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.idx", sha1_file_directory);
-               name = base + len + 11;
-       }
+       static char *name, *base;
 
-       buf = name;
+       return sha1_get_pack_name(sha1, &name, &base, "pack");
+}
 
-       for (i = 0; i < 20; i++) {
-               unsigned int val = *sha1++;
-               *buf++ = hex[val >> 4];
-               *buf++ = hex[val & 0xf];
-       }
+char *sha1_pack_index_name(const unsigned char *sha1)
+{
+       static char *name, *base;
 
-       return base;
+       return sha1_get_pack_name(sha1, &name, &base, "idx");
 }
 
 struct alternate_object_database *alt_odb_list;
@@ -247,7 +254,6 @@ static void read_info_alternates(const char * alternates, int depth);
  */
 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
 {
-       struct stat st;
        const char *objdir = get_object_directory();
        struct alternate_object_database *ent;
        struct alternate_object_database *alt;
@@ -278,7 +284,7 @@ static int link_alt_odb_entry(const char * entry, int len, const char * relative
        ent->base[pfxlen] = ent->base[entlen-1] = 0;
 
        /* Detect cases where alternate disappeared */
-       if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
+       if (!is_directory(ent->base)) {
                error("object directory %s does not exist; "
                      "check .git/objects/info/alternates.",
                      ent->base);
@@ -379,6 +385,28 @@ static void read_info_alternates(const char * relative_base, int depth)
        munmap(map, mapsz);
 }
 
+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/objects\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, alt + strlen(alt), '\n', NULL, 0);
+}
+
+void foreach_alt_odb(alt_odb_fn fn, void *cb)
+{
+       struct alternate_object_database *ent;
+
+       prepare_alt_odb();
+       for (ent = alt_odb_list; ent; ent = ent->next)
+               if (fn(ent, cb))
+                       return;
+}
+
 void prepare_alt_odb(void)
 {
        const char *alt;
@@ -390,26 +418,33 @@ void prepare_alt_odb(void)
        if (!alt) alt = "";
 
        alt_odb_tail = &alt_odb_list;
-       link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
+       link_alt_odb_entries(alt, alt + strlen(alt), PATH_SEP, NULL, 0);
 
        read_info_alternates(get_object_directory(), 0);
 }
 
-static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
+static int has_loose_object_local(const unsigned char *sha1)
 {
        char *name = sha1_file_name(sha1);
-       struct alternate_object_database *alt;
+       return !access(name, F_OK);
+}
 
-       if (!stat(name, st))
-               return name;
+int has_loose_object_nonlocal(const unsigned char *sha1)
+{
+       struct alternate_object_database *alt;
        prepare_alt_odb();
        for (alt = alt_odb_list; alt; alt = alt->next) {
-               name = alt->name;
-               fill_sha1_path(name, sha1);
-               if (!stat(alt->base, st))
-                       return alt->base;
+               fill_sha1_path(alt->name, sha1);
+               if (!access(alt->base, F_OK))
+                       return 1;
        }
-       return NULL;
+       return 0;
+}
+
+static int has_loose_object(const unsigned char *sha1)
+{
+       return has_loose_object_local(sha1) ||
+              has_loose_object_nonlocal(sha1);
 }
 
 static unsigned int pack_used_ctr;
@@ -469,7 +504,7 @@ static int check_packed_git_idx(const char *path,  struct packed_git *p)
                version = ntohl(hdr->idx_version);
                if (version < 2 || version > 2) {
                        munmap(idx_map, idx_size);
-                       return error("index file %s is version %d"
+                       return error("index file %s is version %"PRIu32
                                     " and is not supported by this binary"
                                     " (try upgrading GIT to a newer version)",
                                     path, version);
@@ -637,6 +672,37 @@ void unuse_pack(struct pack_window **w_cursor)
        }
 }
 
+/*
+ * This is used by git-repack in case a newly created pack happens to
+ * contain the same set of objects as an existing one.  In that case
+ * the resulting file might be different even if its name would be the
+ * same.  It is best to close any reference to the old pack before it is
+ * replaced on disk.  Of course no index pointers nor windows for given pack
+ * must subsist at this point.  If ever objects from this pack are requested
+ * again, the new version of the pack will be reinitialized through
+ * reprepare_packed_git().
+ */
+void free_pack_by_name(const char *pack_name)
+{
+       struct packed_git *p, **pp = &packed_git;
+
+       while (*pp) {
+               p = *pp;
+               if (strcmp(pack_name, p->pack_name) == 0) {
+                       close_pack_windows(p);
+                       if (p->pack_fd != -1)
+                               close(p->pack_fd);
+                       if (p->index_data)
+                               munmap((void *)p->index_data, p->index_size);
+                       free(p->bad_object_sha1);
+                       *pp = p->next;
+                       free(p);
+                       return;
+               }
+               pp = &p->next;
+       }
+}
+
 /*
  * Do not call this directly as this leaks p->pack_fd on error return;
  * call open_packed_git() instead.
@@ -680,14 +746,14 @@ static int open_packed_git_1(struct packed_git *p)
        if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
                return error("file %s is not a GIT packfile", p->pack_name);
        if (!pack_version_ok(hdr.hdr_version))
-               return error("packfile %s is version %u and not supported"
-                       " (try upgrading GIT to a newer version)",
+               return error("packfile %s is version %"PRIu32" and not"
+                       " supported (try upgrading GIT to a newer version)",
                        p->pack_name, ntohl(hdr.hdr_version));
 
        /* Verify the pack matches its index. */
        if (p->num_objects != ntohl(hdr.hdr_entries))
-               return error("packfile %s claims to have %u objects"
-                            " while index indicates %u objects",
+               return error("packfile %s claims to have %"PRIu32" objects"
+                            " while index indicates %"PRIu32" objects",
                             p->pack_name, ntohl(hdr.hdr_entries),
                             p->num_objects);
        if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
@@ -790,19 +856,34 @@ unsigned char* use_pack(struct packed_git *p,
        return win->base + offset;
 }
 
+static struct packed_git *alloc_packed_git(int extra)
+{
+       struct packed_git *p = xmalloc(sizeof(*p) + extra);
+       memset(p, 0, sizeof(*p));
+       p->pack_fd = -1;
+       return p;
+}
+
 struct packed_git *add_packed_git(const char *path, int path_len, int local)
 {
        struct stat st;
-       struct packed_git *p = xmalloc(sizeof(*p) + path_len + 2);
+       struct packed_git *p = alloc_packed_git(path_len + 2);
 
        /*
         * Make sure a corresponding .pack file exists and that
         * the index looks sane.
         */
        path_len -= strlen(".idx");
-       if (path_len < 1)
+       if (path_len < 1) {
+               free(p);
                return NULL;
+       }
        memcpy(p->pack_name, path, path_len);
+
+       strcpy(p->pack_name + path_len, ".keep");
+       if (!access(p->pack_name, F_OK))
+               p->pack_keep = 1;
+
        strcpy(p->pack_name + path_len, ".pack");
        if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
                free(p);
@@ -812,14 +893,7 @@ struct packed_git *add_packed_git(const char *path, int path_len, int local)
        /* ok, it looks sane as far as we can check without
         * actually mapping the pack file.
         */
-       p->index_version = 0;
-       p->index_data = NULL;
-       p->index_size = 0;
-       p->num_objects = 0;
        p->pack_size = st.st_size;
-       p->next = NULL;
-       p->windows = NULL;
-       p->pack_fd = -1;
        p->pack_local = local;
        p->mtime = st.st_mtime;
        if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
@@ -829,27 +903,17 @@ struct packed_git *add_packed_git(const char *path, int path_len, int local)
 
 struct packed_git *parse_pack_index(unsigned char *sha1)
 {
-       char *path = sha1_pack_index_name(sha1);
-       return parse_pack_index_file(sha1, path);
-}
-
-struct packed_git *parse_pack_index_file(const unsigned char *sha1,
-                                        const char *idx_path)
-{
+       const char *idx_path = sha1_pack_index_name(sha1);
        const char *path = sha1_pack_name(sha1);
-       struct packed_git *p = xmalloc(sizeof(*p) + strlen(path) + 2);
+       struct packed_git *p = alloc_packed_git(strlen(path) + 1);
 
+       strcpy(p->pack_name, path);
+       hashcpy(p->sha1, sha1);
        if (check_packed_git_idx(idx_path, p)) {
                free(p);
                return NULL;
        }
 
-       strcpy(p->pack_name, path);
-       p->pack_size = 0;
-       p->next = NULL;
-       p->windows = NULL;
-       p->pack_fd = -1;
-       hashcpy(p->sha1, sha1);
        return p;
 }
 
@@ -982,10 +1046,35 @@ void prepare_packed_git(void)
 
 void reprepare_packed_git(void)
 {
+       discard_revindex();
        prepare_packed_git_run_once = 0;
        prepare_packed_git();
 }
 
+static void mark_bad_packed_object(struct packed_git *p,
+                                  const unsigned char *sha1)
+{
+       unsigned i;
+       for (i = 0; i < p->num_bad_objects; i++)
+               if (!hashcmp(sha1, p->bad_object_sha1 + 20 * 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->num_bad_objects++;
+}
+
+static int has_packed_and_bad(const unsigned char *sha1)
+{
+       struct packed_git *p;
+       unsigned i;
+
+       for (p = packed_git; p; p = p->next)
+               for (i = 0; i < p->num_bad_objects; i++)
+                       if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
+                               return 1;
+       return 0;
+}
+
 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
 {
        unsigned char real_sha1[20];
@@ -993,38 +1082,58 @@ int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long siz
        return hashcmp(sha1, real_sha1) ? -1 : 0;
 }
 
+static int git_open_noatime(const char *name)
+{
+       static int sha1_file_open_flag = O_NOATIME;
+       int fd = open(name, O_RDONLY | sha1_file_open_flag);
+
+       /* Might the failure be due to O_NOATIME? */
+       if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
+               fd = open(name, O_RDONLY);
+               if (fd >= 0)
+                       sha1_file_open_flag = 0;
+       }
+       return fd;
+}
+
+static int open_sha1_file(const unsigned char *sha1)
+{
+       int fd;
+       char *name = sha1_file_name(sha1);
+       struct alternate_object_database *alt;
+
+       fd = git_open_noatime(name);
+       if (fd >= 0)
+               return fd;
+
+       prepare_alt_odb();
+       errno = ENOENT;
+       for (alt = alt_odb_list; alt; alt = alt->next) {
+               name = alt->name;
+               fill_sha1_path(name, sha1);
+               fd = git_open_noatime(alt->base);
+               if (fd >= 0)
+                       return fd;
+       }
+       return -1;
+}
+
 static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
 {
-       struct stat st;
        void *map;
        int fd;
-       char *filename = find_sha1_file(sha1, &st);
 
-       if (!filename) {
-               return NULL;
-       }
+       fd = open_sha1_file(sha1);
+       map = NULL;
+       if (fd >= 0) {
+               struct stat st;
 
-       fd = open(filename, O_RDONLY | sha1_file_open_flag);
-       if (fd < 0) {
-               /* See if it works without O_NOATIME */
-               switch (sha1_file_open_flag) {
-               default:
-                       fd = open(filename, O_RDONLY);
-                       if (fd >= 0)
-                               break;
-               /* Fallthrough */
-               case 0:
-                       return NULL;
+               if (!fstat(fd, &st)) {
+                       *size = xsize_t(st.st_size);
+                       map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
                }
-
-               /* If it failed once, it will probably fail again.
-                * Stop using O_NOATIME
-                */
-               sha1_file_open_flag = 0;
+               close(fd);
        }
-       *size = xsize_t(st.st_size);
-       map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
-       close(fd);
        return map;
 }
 
@@ -1044,7 +1153,8 @@ static int legacy_loose_object(unsigned char *map)
                return 0;
 }
 
-unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
+unsigned long unpack_object_header_buffer(const unsigned char *buf,
+               unsigned long len, enum object_type *type, unsigned long *sizep)
 {
        unsigned shift;
        unsigned char c;
@@ -1056,10 +1166,10 @@ unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned lon
        size = c & 15;
        shift = 4;
        while (c & 0x80) {
-               if (len <= used)
-                       return 0;
-               if (sizeof(long) * 8 <= shift)
+               if (len <= used || sizeof(long) * 8 <= shift) {
+                       error("bad object header");
                        return 0;
+               }
                c = buf[used++];
                size += (c & 0x7f) << shift;
                shift += 7;
@@ -1098,7 +1208,7 @@ static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned lon
         * really worth it and we don't write it any longer.  But we
         * can still read it.
         */
-       used = unpack_object_header_gently(map, mapsize, &type, &size);
+       used = unpack_object_header_buffer(map, mapsize, &type, &size);
        if (!used || !valid_loose_object_type[type])
                return -1;
        map += used;
@@ -1247,8 +1357,10 @@ unsigned long get_size_from_delta(struct packed_git *p,
        } while ((st == Z_OK || st == Z_BUF_ERROR) &&
                 stream.total_out < sizeof(delta_head));
        inflateEnd(&stream);
-       if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
-               die("delta data unpack-initial failed");
+       if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
+               error("delta data unpack-initial failed");
+               return 0;
+       }
 
        /* Examine the initial part of the delta to figure out
         * the result size.
@@ -1284,20 +1396,17 @@ static off_t get_delta_base(struct packed_git *p,
                while (c & 128) {
                        base_offset += 1;
                        if (!base_offset || MSB(base_offset, 7))
-                               die("offset value overflow for delta base object");
+                               return 0;  /* overflow */
                        c = base_info[used++];
                        base_offset = (base_offset << 7) + (c & 127);
                }
                base_offset = delta_obj_offset - base_offset;
-               if (base_offset >= delta_obj_offset)
-                       die("delta base offset out of bound");
+               if (base_offset <= 0 || base_offset >= delta_obj_offset)
+                       return 0;  /* out of bound */
                *curpos += used;
        } else if (type == OBJ_REF_DELTA) {
                /* The base entry _must_ be in the same pack */
                base_offset = find_pack_entry_one(base_info, p);
-               if (!base_offset)
-                       die("failed to find delta-pack base object %s",
-                               sha1_to_hex(base_info));
                *curpos += 20;
        } else
                die("I am totally screwed");
@@ -1318,15 +1427,32 @@ static int packed_delta_info(struct packed_git *p,
        off_t base_offset;
 
        base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
+       if (!base_offset)
+               return OBJ_BAD;
        type = packed_object_info(p, base_offset, NULL);
+       if (type <= OBJ_NONE) {
+               struct revindex_entry *revidx;
+               const unsigned char *base_sha1;
+               revidx = find_pack_revindex(p, base_offset);
+               if (!revidx)
+                       return OBJ_BAD;
+               base_sha1 = nth_packed_object_sha1(p, revidx->nr);
+               mark_bad_packed_object(p, base_sha1);
+               type = sha1_object_info(base_sha1, NULL);
+               if (type <= OBJ_NONE)
+                       return OBJ_BAD;
+       }
 
        /* We choose to only get the type of the base object and
         * ignore potentially corrupt pack file that expects the delta
         * based on a base with a wrong size.  This saves tons of
         * inflate() calls.
         */
-       if (sizep)
+       if (sizep) {
                *sizep = get_size_from_delta(p, w_curs, curpos);
+               if (*sizep == 0)
+                       type = OBJ_BAD;
+       }
 
        return type;
 }
@@ -1348,10 +1474,11 @@ static int unpack_object_header(struct packed_git *p,
         * insane, so we know won't exceed what we have been given.
         */
        base = use_pack(p, w_curs, *curpos, &left);
-       used = unpack_object_header_gently(base, left, &type, sizep);
-       if (!used)
-               die("object offset outside of pack file");
-       *curpos += used;
+       used = unpack_object_header_buffer(base, left, &type, sizep);
+       if (!used) {
+               type = OBJ_BAD;
+       } else
+               *curpos += used;
 
        return type;
 }
@@ -1390,6 +1517,9 @@ const char *packed_object_info_detail(struct packed_git *p,
                        return typename(type);
                case OBJ_OFS_DELTA:
                        obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
+                       if (!obj_offset)
+                               die("pack %s contains bad delta base reference of type %s",
+                                   p->pack_name, typename(type));
                        if (*delta_chain_length == 0) {
                                revidx = find_pack_revindex(p, obj_offset);
                                hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
@@ -1432,8 +1562,9 @@ static int packed_object_info(struct packed_git *p, off_t obj_offset,
                        *sizep = size;
                break;
        default:
-               die("pack %s contains unknown object type %d",
-                   p->pack_name, type);
+               error("unknown object type %i at offset %"PRIuMAX" in %s",
+                     type, (uintmax_t)obj_offset, p->pack_name);
+               type = OBJ_BAD;
        }
        unuse_pack(&w_curs);
        return type;
@@ -1505,11 +1636,9 @@ static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
        struct delta_base_cache_entry *ent = delta_base_cache + hash;
 
        ret = ent->data;
-       if (ret && ent->p == p && ent->base_offset == base_offset)
-               goto found_cache_entry;
-       return unpack_entry(p, base_offset, type, base_size);
+       if (!ret || ent->p != p || ent->base_offset != base_offset)
+               return unpack_entry(p, base_offset, type, base_size);
 
-found_cache_entry:
        if (!keep_cache) {
                ent->data = NULL;
                ent->lru.next->prev = ent->lru.prev;
@@ -1571,6 +1700,9 @@ static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
        delta_base_cache_lru.prev = &ent->lru;
 }
 
+static void *read_object(const unsigned char *sha1, enum object_type *type,
+                        unsigned long *size);
+
 static void *unpack_delta_entry(struct packed_git *p,
                                struct pack_window **w_curs,
                                off_t curpos,
@@ -1584,17 +1716,45 @@ static void *unpack_delta_entry(struct packed_git *p,
        off_t base_offset;
 
        base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
+       if (!base_offset) {
+               error("failed to validate delta base reference "
+                     "at offset %"PRIuMAX" from %s",
+                     (uintmax_t)curpos, p->pack_name);
+               return NULL;
+       }
+       unuse_pack(w_curs);
        base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
-       if (!base)
-               die("failed to read delta base object"
-                   " at %"PRIuMAX" from %s",
-                   (uintmax_t)base_offset, p->pack_name);
+       if (!base) {
+               /*
+                * We're probably in deep shit, but let's try to fetch
+                * the required base anyway from another pack or loose.
+                * This is costly but should happen only in the presence
+                * of a corrupted pack, and is better than failing outright.
+                */
+               struct revindex_entry *revidx;
+               const unsigned char *base_sha1;
+               revidx = find_pack_revindex(p, base_offset);
+               if (!revidx)
+                       return NULL;
+               base_sha1 = nth_packed_object_sha1(p, revidx->nr);
+               error("failed to read delta base object %s"
+                     " at offset %"PRIuMAX" from %s",
+                     sha1_to_hex(base_sha1), (uintmax_t)base_offset,
+                     p->pack_name);
+               mark_bad_packed_object(p, base_sha1);
+               base = read_object(base_sha1, type, &base_size);
+               if (!base)
+                       return NULL;
+       }
 
        delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
-       if (!delta_data)
-               die("failed to unpack compressed delta"
-                   " at %"PRIuMAX" from %s",
-                   (uintmax_t)curpos, p->pack_name);
+       if (!delta_data) {
+               error("failed to unpack compressed delta "
+                     "at offset %"PRIuMAX" from %s",
+                     (uintmax_t)curpos, p->pack_name);
+               free(base);
+               return NULL;
+       }
        result = patch_delta(base, base_size,
                             delta_data, delta_size,
                             sizep);
@@ -1605,6 +1765,8 @@ static void *unpack_delta_entry(struct packed_git *p,
        return result;
 }
 
+int do_check_packed_object_crc;
+
 void *unpack_entry(struct packed_git *p, off_t obj_offset,
                   enum object_type *type, unsigned long *sizep)
 {
@@ -1612,6 +1774,20 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
        off_t curpos = obj_offset;
        void *data;
 
+       if (do_check_packed_object_crc && p->index_version > 1) {
+               struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
+               unsigned long len = revidx[1].offset - obj_offset;
+               if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
+                       const unsigned char *sha1 =
+                               nth_packed_object_sha1(p, revidx->nr);
+                       error("bad packed object CRC for %s",
+                             sha1_to_hex(sha1));
+                       mark_bad_packed_object(p, sha1);
+                       unuse_pack(&w_curs);
+                       return NULL;
+               }
+       }
+
        *type = unpack_object_header(p, &w_curs, &curpos, sizep);
        switch (*type) {
        case OBJ_OFS_DELTA:
@@ -1626,7 +1802,9 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
                data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
                break;
        default:
-               die("unknown object type %i in %s", *type, p->pack_name);
+               data = NULL;
+               error("unknown object type %i at offset %"PRIuMAX" in %s",
+                     *type, (uintmax_t)obj_offset, p->pack_name);
        }
        unuse_pack(&w_curs);
        return data;
@@ -1652,7 +1830,7 @@ const unsigned char *nth_packed_object_sha1(struct packed_git *p,
        }
 }
 
-static off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
+off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
 {
        const unsigned char *index = p->index_data;
        index += 4 * 256;
@@ -1675,7 +1853,12 @@ off_t find_pack_entry_one(const unsigned char *sha1,
 {
        const uint32_t *level1_ofs = p->index_data;
        const unsigned char *index = p->index_data;
-       unsigned hi, lo;
+       unsigned hi, lo, stride;
+       static int use_lookup = -1;
+       static int debug_lookup = -1;
+
+       if (debug_lookup < 0)
+               debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
 
        if (!index) {
                if (open_pack_index(p))
@@ -1690,11 +1873,34 @@ off_t find_pack_entry_one(const unsigned char *sha1,
        index += 4 * 256;
        hi = ntohl(level1_ofs[*sha1]);
        lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
+       if (p->index_version > 1) {
+               stride = 20;
+       } else {
+               stride = 24;
+               index += 4;
+       }
+
+       if (debug_lookup)
+               printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
+                      sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
+
+       if (use_lookup < 0)
+               use_lookup = !!getenv("GIT_USE_LOOKUP");
+       if (use_lookup) {
+               int pos = sha1_entry_pos(index, stride, 0,
+                                        lo, hi, p->num_objects, sha1);
+               if (pos < 0)
+                       return 0;
+               return nth_packed_object_offset(p, pos);
+       }
 
        do {
                unsigned mi = (lo + hi) / 2;
-               unsigned x = (p->index_version > 1) ? (mi * 20) : (mi * 24 + 4);
-               int cmp = hashcmp(index + x, sha1);
+               int cmp = hashcmp(index + mi * stride, sha1);
+
+               if (debug_lookup)
+                       printf("lo %u hi %u rg %u mi %u\n",
+                              lo, hi, hi - lo, mi);
                if (!cmp)
                        return nth_packed_object_offset(p, mi);
                if (cmp > 0)
@@ -1744,6 +1950,13 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, cons
                                goto next;
                }
 
+               if (p->num_bad_objects) {
+                       unsigned i;
+                       for (i = 0; i < p->num_bad_objects; i++)
+                               if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
+                                       goto next;
+               }
+
                offset = find_pack_entry_one(sha1, p);
                if (offset) {
                        /*
@@ -1815,24 +2028,51 @@ static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *size
 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
 {
        struct pack_entry e;
+       int status;
 
        if (!find_pack_entry(sha1, &e, NULL)) {
+               /* Most likely it's a loose object. */
+               status = sha1_loose_object_info(sha1, sizep);
+               if (status >= 0)
+                       return status;
+
+               /* Not a loose object; someone else may have just packed it. */
                reprepare_packed_git();
                if (!find_pack_entry(sha1, &e, NULL))
-                       return sha1_loose_object_info(sha1, sizep);
+                       return status;
        }
-       return packed_object_info(e.p, e.offset, sizep);
+
+       status = packed_object_info(e.p, e.offset, sizep);
+       if (status < 0) {
+               mark_bad_packed_object(e.p, sha1);
+               status = sha1_object_info(sha1, sizep);
+       }
+
+       return status;
 }
 
 static void *read_packed_sha1(const unsigned char *sha1,
                              enum object_type *type, unsigned long *size)
 {
        struct pack_entry e;
+       void *data;
 
        if (!find_pack_entry(sha1, &e, NULL))
                return NULL;
-       else
-               return cache_or_unpack_entry(e.p, e.offset, size, type, 1);
+       data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
+       if (!data) {
+               /*
+                * We're probably in deep shit, but let's try to fetch
+                * the required object anyway from another pack or loose.
+                * This should happen only in the presence of a corrupted
+                * pack, and is better than failing outright.
+                */
+               error("failed to read object %s at offset %"PRIuMAX" from %s",
+                     sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
+               mark_bad_packed_object(e.p, sha1);
+               data = read_object(sha1, type, size);
+       }
+       return data;
 }
 
 /*
@@ -1850,9 +2090,7 @@ static struct cached_object {
 static int cached_object_nr, cached_object_alloc;
 
 static struct cached_object empty_tree = {
-       /* empty tree sha1: 4b825dc642cb6eb9a060e54bf8d69288fbee4904 */
-       "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60"
-       "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04",
+       EMPTY_TREE_SHA1_BIN,
        OBJ_TREE,
        "",
        0
@@ -1895,8 +2133,8 @@ int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
        return 0;
 }
 
-void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
-                    unsigned long *size)
+static void *read_object(const unsigned char *sha1, enum object_type *type,
+                        unsigned long *size)
 {
        unsigned long mapsize;
        void *map, *buf;
@@ -1922,6 +2160,16 @@ void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
        return read_packed_sha1(sha1, type, size);
 }
 
+void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
+                    unsigned long *size)
+{
+       void *data = read_object(sha1, type, size);
+       /* legacy behavior is to die on corrupted objects */
+       if (!data && (has_loose_object(sha1) || has_packed_and_bad(sha1)))
+               die("object %s is corrupted", sha1_to_hex(sha1));
+       return data;
+}
+
 void *read_object_with_reference(const unsigned char *sha1,
                                 const char *required_type_name,
                                 unsigned long *size,
@@ -1974,53 +2222,16 @@ static void write_sha1_file_prepare(const void *buf, unsigned long len,
                                     const char *type, unsigned char *sha1,
                                     char *hdr, int *hdrlen)
 {
-       SHA_CTX c;
+       git_SHA_CTX c;
 
        /* Generate the header */
        *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
 
        /* Sha1.. */
-       SHA1_Init(&c);
-       SHA1_Update(&c, hdr, *hdrlen);
-       SHA1_Update(&c, buf, len);
-       SHA1_Final(sha1, &c);
-}
-
-/*
- * Link the tempfile to the final place, possibly creating the
- * last directory level as you do so.
- *
- * Returns the errno on failure, 0 on success.
- */
-static int link_temp_to_file(const char *tmpfile, const char *filename)
-{
-       int ret;
-       char *dir;
-
-       if (!link(tmpfile, filename))
-               return 0;
-
-       /*
-        * Try to mkdir the last path component if that failed.
-        *
-        * Re-try the "link()" regardless of whether the mkdir
-        * succeeds, since a race might mean that somebody
-        * else succeeded.
-        */
-       ret = errno;
-       dir = strrchr(filename, '/');
-       if (dir) {
-               *dir = 0;
-               if (!mkdir(filename, 0777) && adjust_shared_perm(filename)) {
-                       *dir = '/';
-                       return -2;
-               }
-               *dir = '/';
-               if (!link(tmpfile, filename))
-                       return 0;
-               ret = errno;
-       }
-       return ret;
+       git_SHA1_Init(&c);
+       git_SHA1_Update(&c, hdr, *hdrlen);
+       git_SHA1_Update(&c, buf, len);
+       git_SHA1_Final(sha1, &c);
 }
 
 /*
@@ -2028,7 +2239,9 @@ static int link_temp_to_file(const char *tmpfile, const char *filename)
  */
 int move_temp_to_file(const char *tmpfile, const char *filename)
 {
-       int ret = link_temp_to_file(tmpfile, filename);
+       int ret = 0;
+       if (link(tmpfile, filename))
+               ret = errno;
 
        /*
         * Coda hack - coda doesn't like cross-directory links,
@@ -2073,45 +2286,70 @@ int hash_sha1_file(const void *buf, unsigned long len, const char *type,
        return 0;
 }
 
-int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
+/* Finalize a file on disk, and close it. */
+static void close_sha1_file(int fd)
 {
-       int size, ret;
-       unsigned char *compressed;
-       z_stream stream;
-       unsigned char sha1[20];
-       char *filename;
-       static char tmpfile[PATH_MAX];
-       char hdr[32];
-       int fd, hdrlen;
+       if (fsync_object_files)
+               fsync_or_die(fd, "sha1 file");
+       fchmod(fd, 0444);
+       if (close(fd) != 0)
+               die("unable to write sha1 file");
+}
 
-       /* 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);
-       filename = sha1_file_name(sha1);
-       if (returnsha1)
-               hashcpy(returnsha1, sha1);
-       if (has_sha1_file(sha1))
-               return 0;
-       fd = open(filename, O_RDONLY);
-       if (fd >= 0) {
-               /*
-                * FIXME!!! We might do collision checking here, but we'd
-                * need to uncompress the old file and check it. Later.
-                */
-               close(fd);
+/* Size of directory component, including the ending '/' */
+static inline int directory_size(const char *filename)
+{
+       const char *s = strrchr(filename, '/');
+       if (!s)
                return 0;
+       return s - filename + 1;
+}
+
+/*
+ * This creates a temporary file in the same directory as the final
+ * '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)
+{
+       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 = mkstemp(buffer);
+       if (fd < 0 && dirlen && errno == ENOENT) {
+               /* Make sure the directory exists */
+               memcpy(buffer, filename, dirlen);
+               buffer[dirlen-1] = 0;
+               if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
+                       return -1;
 
-       if (errno != ENOENT) {
-               return error("sha1 file %s: %s\n", filename, strerror(errno));
+               /* Try again */
+               strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
+               fd = mkstemp(buffer);
        }
+       return fd;
+}
 
-       snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
+static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
+                             void *buf, unsigned long len, time_t mtime)
+{
+       int fd, size, ret;
+       unsigned char *compressed;
+       z_stream stream;
+       char *filename;
+       static char tmpfile[PATH_MAX];
 
-       fd = mkstemp(tmpfile);
+       filename = sha1_file_name(sha1);
+       fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
        if (fd < 0) {
-               if (errno == EPERM)
+               if (errno == EACCES)
                        return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
                else
                        return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
@@ -2148,156 +2386,57 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
 
        if (write_buffer(fd, compressed, size) < 0)
                die("unable to write sha1 file");
-       fchmod(fd, 0444);
-       if (close(fd))
-               die("unable to write sha1 file");
+       close_sha1_file(fd);
        free(compressed);
 
+       if (mtime) {
+               struct utimbuf utb;
+               utb.actime = mtime;
+               utb.modtime = mtime;
+               if (utime(tmpfile, &utb) < 0)
+                       warning("failed utime() on %s: %s",
+                               tmpfile, strerror(errno));
+       }
+
        return move_temp_to_file(tmpfile, filename);
 }
 
-/*
- * We need to unpack and recompress the object for writing
- * it out to a different file.
- */
-static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
+int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
 {
-       size_t size;
-       z_stream stream;
-       unsigned char *unpacked;
-       unsigned long len;
-       enum object_type type;
+       unsigned char sha1[20];
        char hdr[32];
        int hdrlen;
-       void *buf;
-
-       /* need to unpack and recompress it by itself */
-       unpacked = read_packed_sha1(sha1, &type, &len);
-       if (!unpacked)
-               error("cannot read sha1_file for %s", sha1_to_hex(sha1));
-
-       hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
-
-       /* Set it up */
-       memset(&stream, 0, sizeof(stream));
-       deflateInit(&stream, zlib_compression_level);
-       size = deflateBound(&stream, len + hdrlen);
-       buf = xmalloc(size);
-
-       /* Compress it */
-       stream.next_out = buf;
-       stream.avail_out = size;
-
-       /* First header.. */
-       stream.next_in = (void *)hdr;
-       stream.avail_in = hdrlen;
-       while (deflate(&stream, 0) == Z_OK)
-               /* nothing */;
-
-       /* Then the data itself.. */
-       stream.next_in = unpacked;
-       stream.avail_in = len;
-       while (deflate(&stream, Z_FINISH) == Z_OK)
-               /* nothing */;
-       deflateEnd(&stream);
-       free(unpacked);
-
-       *objsize = stream.total_out;
-       return buf;
-}
-
-int write_sha1_to_fd(int fd, const unsigned char *sha1)
-{
-       int retval;
-       unsigned long objsize;
-       void *buf = map_sha1_file(sha1, &objsize);
 
-       if (buf) {
-               retval = write_buffer(fd, buf, objsize);
-               munmap(buf, objsize);
-               return retval;
-       }
-
-       buf = repack_object(sha1, &objsize);
-       retval = write_buffer(fd, buf, objsize);
-       free(buf);
-       return retval;
+       /* 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 (has_sha1_file(sha1))
+               return 0;
+       return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
 }
 
-int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
-                      size_t bufsize, size_t *bufposn)
+int force_object_loose(const unsigned char *sha1, time_t mtime)
 {
-       char tmpfile[PATH_MAX];
-       int local;
-       z_stream stream;
-       unsigned char real_sha1[20];
-       unsigned char discard[4096];
+       void *buf;
+       unsigned long len;
+       enum object_type type;
+       char hdr[32];
+       int hdrlen;
        int ret;
-       SHA_CTX c;
-
-       snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
-
-       local = mkstemp(tmpfile);
-       if (local < 0) {
-               if (errno == EPERM)
-                       return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
-               else
-                       return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
-       }
-
-       memset(&stream, 0, sizeof(stream));
-
-       inflateInit(&stream);
-
-       SHA1_Init(&c);
-
-       do {
-               ssize_t size;
-               if (*bufposn) {
-                       stream.avail_in = *bufposn;
-                       stream.next_in = (unsigned char *) buffer;
-                       do {
-                               stream.next_out = discard;
-                               stream.avail_out = sizeof(discard);
-                               ret = inflate(&stream, Z_SYNC_FLUSH);
-                               SHA1_Update(&c, discard, sizeof(discard) -
-                                           stream.avail_out);
-                       } while (stream.avail_in && ret == Z_OK);
-                       if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
-                               die("unable to write sha1 file");
-                       memmove(buffer, buffer + *bufposn - stream.avail_in,
-                               stream.avail_in);
-                       *bufposn = stream.avail_in;
-                       if (ret != Z_OK)
-                               break;
-               }
-               size = xread(fd, buffer + *bufposn, bufsize - *bufposn);
-               if (size <= 0) {
-                       close(local);
-                       unlink(tmpfile);
-                       if (!size)
-                               return error("Connection closed?");
-                       perror("Reading from connection");
-                       return -1;
-               }
-               *bufposn += size;
-       } while (1);
-       inflateEnd(&stream);
 
-       fchmod(local, 0444);
-       if (close(local) != 0)
-               die("unable to write sha1 file");
-       SHA1_Final(real_sha1, &c);
-       if (ret != Z_STREAM_END) {
-               unlink(tmpfile);
-               return error("File %s corrupted", sha1_to_hex(sha1));
-       }
-       if (hashcmp(sha1, real_sha1)) {
-               unlink(tmpfile);
-               return error("File %s has bad hash", sha1_to_hex(sha1));
-       }
+       if (has_loose_object(sha1))
+               return 0;
+       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;
+       ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
+       free(buf);
 
-       return move_temp_to_file(tmpfile, sha1_file_name(sha1));
+       return ret;
 }
 
 int has_pack_index(const unsigned char *sha1)
@@ -2324,59 +2463,28 @@ int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
 
 int has_sha1_file(const unsigned char *sha1)
 {
-       struct stat st;
        struct pack_entry e;
 
        if (find_pack_entry(sha1, &e, NULL))
                return 1;
-       return find_sha1_file(sha1, &st) ? 1 : 0;
-}
-
-int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
-{
-       struct strbuf buf;
-       int ret;
-
-       strbuf_init(&buf, 0);
-       if (strbuf_read(&buf, fd, 4096) < 0) {
-               strbuf_release(&buf);
-               return -1;
-       }
-
-       if (!type)
-               type = blob_type;
-       if (write_object)
-               ret = write_sha1_file(buf.buf, buf.len, type, sha1);
-       else
-               ret = hash_sha1_file(buf.buf, buf.len, type, sha1);
-       strbuf_release(&buf);
-
-       return ret;
+       return has_loose_object(sha1);
 }
 
-int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
-            enum object_type type, const char *path)
+static int index_mem(unsigned char *sha1, void *buf, size_t size,
+                    int write_object, enum object_type type, const char *path)
 {
-       size_t size = xsize_t(st->st_size);
-       void *buf = NULL;
        int ret, re_allocated = 0;
 
-       if (size)
-               buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
-       close(fd);
-
        if (!type)
                type = OBJ_BLOB;
 
        /*
         * Convert blobs to git internal format
         */
-       if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
-               struct strbuf nbuf;
-               strbuf_init(&nbuf, 0);
+       if ((type == OBJ_BLOB) && path) {
+               struct strbuf nbuf = STRBUF_INIT;
                if (convert_to_git(path, buf, size, &nbuf,
                                   write_object ? safe_crlf : 0)) {
-                       munmap(buf, size);
                        buf = strbuf_detach(&nbuf, &size);
                        re_allocated = 1;
                }
@@ -2386,20 +2494,39 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
                ret = write_sha1_file(buf, size, typename(type), sha1);
        else
                ret = hash_sha1_file(buf, size, typename(type), sha1);
-       if (re_allocated) {
+       if (re_allocated)
                free(buf);
-               return ret;
-       }
-       if (size)
+       return ret;
+}
+
+int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
+            enum object_type type, const char *path)
+{
+       int ret;
+       size_t size = xsize_t(st->st_size);
+
+       if (!S_ISREG(st->st_mode)) {
+               struct strbuf sbuf = STRBUF_INIT;
+               if (strbuf_read(&sbuf, fd, 4096) >= 0)
+                       ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object,
+                                       type, path);
+               else
+                       ret = -1;
+               strbuf_release(&sbuf);
+       } else if (size) {
+               void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+               ret = index_mem(sha1, buf, size, write_object, type, path);
                munmap(buf, size);
+       } else
+               ret = index_mem(sha1, NULL, size, write_object, type, path);
+       close(fd);
        return ret;
 }
 
 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
 {
        int fd;
-       char *target;
-       size_t len;
+       struct strbuf sb = STRBUF_INIT;
 
        switch (st->st_mode & S_IFMT) {
        case S_IFREG:
@@ -2412,20 +2539,17 @@ int index_path(unsigned char *sha1, const char *path, struct stat *st, int write
                                     path);
                break;
        case S_IFLNK:
-               len = xsize_t(st->st_size);
-               target = xmalloc(len + 1);
-               if (readlink(path, target, len + 1) != st->st_size) {
+               if (strbuf_readlink(&sb, path, st->st_size)) {
                        char *errstr = strerror(errno);
-                       free(target);
                        return error("readlink(\"%s\"): %s", path,
                                     errstr);
                }
                if (!write_object)
-                       hash_sha1_file(target, len, blob_type, sha1);
-               else if (write_sha1_file(target, len, blob_type, sha1))
+                       hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
+               else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
                        return error("%s: failed to insert into database",
                                     path);
-               free(target);
+               strbuf_release(&sb);
                break;
        case S_IFDIR:
                return resolve_gitlink_ref(path, "HEAD", sha1);
@@ -2437,16 +2561,10 @@ int index_path(unsigned char *sha1, const char *path, struct stat *st, int write
 
 int read_pack_header(int fd, struct pack_header *header)
 {
-       char *c = (char*)header;
-       ssize_t remaining = sizeof(struct pack_header);
-       do {
-               ssize_t r = xread(fd, c, remaining);
-               if (r <= 0)
-                       /* "eof before pack header was fully read" */
-                       return PH_ERROR_EOF;
-               remaining -= r;
-               c += r;
-       } while (remaining > 0);
+       if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
+               /* "eof before pack header was fully read" */
+               return PH_ERROR_EOF;
+
        if (header->hdr_signature != htonl(PACK_SIGNATURE))
                /* "protocol error (pack signature mismatch detected)" */
                return PH_ERROR_PACK_SIGNATURE;