Documentation: revise top of git man page

diff --git a/sha1_file.c b/sha1_file.c
index 1d799f793a936a696cea86deb36fa2bdb04c29f4..58edec0bb677e480552b9464e905ea983747c183 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -247,6 +247,7 @@ static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
                for ( ; cp < ep && *cp != sep; cp++)
                        ;
                if (last != cp) {
+                       struct stat st;
                        struct alternate_object_database *alt;
                        /* 43 = 40-byte + 2 '/' + terminating NUL */
                        int pfxlen = cp - last;
@@ -269,9 +270,19 @@ static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
                        }
                        else
                                memcpy(ent->base, last, pfxlen);
+
                        ent->name = ent->base + pfxlen + 1;
-                       ent->base[pfxlen] = ent->base[pfxlen + 3] = '/';
-                       ent->base[entlen-1] = 0;
+                       ent->base[pfxlen + 3] = '/';
+                       ent->base[pfxlen] = ent->base[entlen-1] = 0;
+
+                       /* Detect cases where alternate disappeared */
+                       if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
+                               error("object directory %s does not exist; "
+                                     "check .git/objects/info/alternates.",
+                                     ent->base);
+                               goto bad;
+                       }
+                       ent->base[pfxlen] = '/';
 
                        /* Prevent the common mistake of listing the same
                         * thing twice, or object directory itself.
@@ -552,7 +563,9 @@ static void prepare_packed_git_one(char *objdir, int local)
        len = strlen(path);
        dir = opendir(path);
        if (!dir) {
-               fprintf(stderr, "unable to open object pack directory: %s: %s\n", path, strerror(errno));
+               if (errno != ENOENT)
+                       error("unable to open object pack directory: %s: %s",
+                             path, strerror(errno));
                return;
        }
        path[len++] = '/';
@@ -828,6 +841,25 @@ static unsigned long unpack_object_header(struct packed_git *p, unsigned long of
        return offset;
 }
 
+int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
+                          unsigned char *base, unsigned long *sizep,
+                          enum object_type *kindp)
+{
+       unsigned long ptr;
+       int status = -1;
+
+       use_packed_git(p);
+       ptr = offset;
+       ptr = unpack_object_header(p, ptr, kindp, sizep);
+       if (*kindp != OBJ_DELTA)
+               goto done;
+       memcpy(base, p->pack_base + ptr, 20);
+       status = 0;
+ done:
+       unuse_packed_git(p);
+       return status;
+}
+
 void packed_object_info_detail(struct pack_entry *e,
                               char *type,
                               unsigned long *size,
@@ -941,6 +973,16 @@ static void *unpack_delta_entry(unsigned char *base_sha1,
 
        if (left < 20)
                die("truncated pack file");
+
+       /* The base entry _must_ be in the same pack */
+       if (!find_pack_entry_one(base_sha1, &base_ent, p))
+               die("failed to find delta-pack base object %s",
+                   sha1_to_hex(base_sha1));
+       base = unpack_entry_gently(&base_ent, type, &base_size);
+       if (!base)
+               die("failed to read delta-pack base object %s",
+                   sha1_to_hex(base_sha1));
+
        data = base_sha1 + 20;
        data_size = left - 20;
        delta_data = xmalloc(delta_size);
@@ -958,14 +1000,6 @@ static void *unpack_delta_entry(unsigned char *base_sha1,
        if ((st != Z_STREAM_END) || stream.total_out != delta_size)
                die("delta data unpack failed");
 
-       /* The base entry _must_ be in the same pack */
-       if (!find_pack_entry_one(base_sha1, &base_ent, p))
-               die("failed to find delta-pack base object %s",
-                   sha1_to_hex(base_sha1));
-       base = unpack_entry_gently(&base_ent, type, &base_size);
-       if (!base)
-               die("failed to read delta-pack base object %s",
-                   sha1_to_hex(base_sha1));
        result = patch_delta(base, base_size,
                             delta_data, delta_size,
                             &result_size);
@@ -1481,7 +1515,8 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
 
        local = mkstemp(tmpfile);
        if (local < 0)
-               return error("Couldn't open %s for %s\n", tmpfile, sha1_to_hex(sha1));
+               return error("Couldn't open %s for %s",
+                            tmpfile, sha1_to_hex(sha1));
 
        memset(&stream, 0, sizeof(stream));
 
@@ -1529,7 +1564,7 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
        }
        if (memcmp(sha1, real_sha1, 20)) {
                unlink(tmpfile);
-               return error("File %s has bad hash\n", sha1_to_hex(sha1));
+               return error("File %s has bad hash", sha1_to_hex(sha1));
        }
 
        return move_temp_to_file(tmpfile, sha1_file_name(sha1));