Fix botched "leak fix"
[gitweb.git] / upload-pack.c
index 47560c9527b9c17db34f10e78d7c1f0d99b746e1..3648aae1a777aec4bba77b40b9cf6da484190441 100644 (file)
@@ -1,23 +1,39 @@
 #include "cache.h"
 #include "refs.h"
 #include "pkt-line.h"
+#include "sideband.h"
 #include "tag.h"
 #include "object.h"
 #include "commit.h"
 #include "exec_cmd.h"
+#include "diff.h"
+#include "revision.h"
+#include "list-objects.h"
 
 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
 
-#define THEY_HAVE (1U << 0)
-#define OUR_REF (1U << 1)
-#define WANTED (1U << 2)
-#define MAX_HAS 256
-#define MAX_NEEDS 256
-static int nr_has = 0, nr_needs = 0, multi_ack = 0, nr_our_refs = 0;
-static int use_thin_pack = 0;
-static unsigned char has_sha1[MAX_HAS][20];
-static unsigned char needs_sha1[MAX_NEEDS][20];
-static unsigned int timeout = 0;
+/* bits #0..7 in revision.h, #8..10 in commit.c */
+#define THEY_HAVE      (1u << 11)
+#define OUR_REF                (1u << 12)
+#define WANTED         (1u << 13)
+#define COMMON_KNOWN   (1u << 14)
+#define REACHABLE      (1u << 15)
+
+#define SHALLOW                (1u << 16)
+#define NOT_SHALLOW    (1u << 17)
+#define CLIENT_SHALLOW (1u << 18)
+
+static unsigned long oldest_have;
+
+static int multi_ack, nr_our_refs;
+static int use_thin_pack, use_ofs_delta;
+static struct object_array have_obj;
+static struct object_array want_obj;
+static unsigned int timeout;
+/* 0 for no sideband,
+ * otherwise maximum packet size (up to 65520 bytes).
+ */
+static int use_sideband;
 
 static void reset_timeout(void)
 {
@@ -31,91 +47,390 @@ static int strip(char *line, int len)
        return len;
 }
 
+static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
+{
+       if (use_sideband)
+               return send_sideband(1, fd, data, sz, use_sideband);
+       if (fd == 3)
+               /* emergency quit */
+               fd = 2;
+       if (fd == 2) {
+               /* XXX: are we happy to lose stuff here? */
+               xwrite(fd, data, sz);
+               return sz;
+       }
+       return safe_write(fd, data, sz);
+}
+
+FILE *pack_pipe = NULL;
+static void show_commit(struct commit *commit)
+{
+       if (commit->object.flags & BOUNDARY)
+               fputc('-', pack_pipe);
+       if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
+               die("broken output pipe");
+       fputc('\n', pack_pipe);
+       fflush(pack_pipe);
+       free(commit->buffer);
+       commit->buffer = NULL;
+}
+
+static void show_object(struct object_array_entry *p)
+{
+       /* An object with name "foo\n0000000..." can be used to
+        * confuse downstream git-pack-objects very badly.
+        */
+       const char *ep = strchr(p->name, '\n');
+       if (ep) {
+               fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(p->item->sha1),
+                      (int) (ep - p->name),
+                      p->name);
+       }
+       else
+               fprintf(pack_pipe, "%s %s\n",
+                               sha1_to_hex(p->item->sha1), p->name);
+}
+
+static void show_edge(struct commit *commit)
+{
+       fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
+}
+
 static void create_pack_file(void)
 {
-       int fd[2];
-       pid_t pid;
-       int create_full_pack = (nr_our_refs == nr_needs && !nr_has);
+       /* Pipes between rev-list to pack-objects, pack-objects to us
+        * and pack-objects error stream for progress bar.
+        */
+       int lp_pipe[2], pu_pipe[2], pe_pipe[2];
+       pid_t pid_rev_list, pid_pack_objects;
+       int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
+       char data[8193], progress[128];
+       char abort_msg[] = "aborting due to possible repository "
+               "corruption on the remote side.";
+       int buffered = -1;
 
-       if (pipe(fd) < 0)
+       if (pipe(lp_pipe) < 0)
                die("git-upload-pack: unable to create pipe");
-       pid = fork();
-       if (pid < 0)
+       pid_rev_list = fork();
+       if (pid_rev_list < 0)
                die("git-upload-pack: unable to fork git-rev-list");
 
-       if (!pid) {
+       if (!pid_rev_list) {
                int i;
-               int args;
-               const char **argv;
-               char *buf;
-               char **p;
+               struct rev_info revs;
 
-               if (create_full_pack) {
-                       args = 10;
+               pack_pipe = fdopen(lp_pipe[1], "w");
+
+               if (create_full_pack)
                        use_thin_pack = 0; /* no point doing it */
+               init_revisions(&revs, NULL);
+               revs.tag_objects = 1;
+               revs.tree_objects = 1;
+               revs.blob_objects = 1;
+               if (use_thin_pack)
+                       revs.edge_hint = 1;
+
+               if (create_full_pack) {
+                       const char *args[] = {"rev-list", "--all", NULL};
+                       setup_revisions(2, args, &revs, NULL);
+               } else {
+                       for (i = 0; i < want_obj.nr; i++) {
+                               struct object *o = want_obj.objects[i].item;
+                               /* why??? */
+                               o->flags &= ~UNINTERESTING;
+                               add_pending_object(&revs, o, NULL);
+                       }
+                       for (i = 0; i < have_obj.nr; i++) {
+                               struct object *o = have_obj.objects[i].item;
+                               o->flags |= UNINTERESTING;
+                               add_pending_object(&revs, o, NULL);
+                       }
+                       setup_revisions(0, NULL, &revs, NULL);
                }
-               else
-                       args = nr_has + nr_needs + 5;
-               p = xmalloc(args * sizeof(char *));
-               argv = (const char **) p;
-               buf = xmalloc(args * 45);
-
-               dup2(fd[1], 1);
-               close(0);
-               close(fd[0]);
-               close(fd[1]);
-               *p++ = "rev-list";
-               *p++ = use_thin_pack ? "--objects-edge" : "--objects";
-               if (create_full_pack || MAX_NEEDS <= nr_needs)
-                       *p++ = "--all";
-               else {
-                       for (i = 0; i < nr_needs; i++) {
-                               *p++ = buf;
-                               memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
-                               buf += 41;
+               prepare_revision_walk(&revs);
+               mark_edges_uninteresting(revs.commits, &revs, show_edge);
+               traverse_commit_list(&revs, show_commit, show_object);
+               exit(0);
+       }
+
+       if (pipe(pu_pipe) < 0)
+               die("git-upload-pack: unable to create pipe");
+       if (pipe(pe_pipe) < 0)
+               die("git-upload-pack: unable to create pipe");
+       pid_pack_objects = fork();
+       if (pid_pack_objects < 0) {
+               /* daemon sets things up to ignore TERM */
+               kill(pid_rev_list, SIGKILL);
+               die("git-upload-pack: unable to fork git-pack-objects");
+       }
+       if (!pid_pack_objects) {
+               dup2(lp_pipe[0], 0);
+               dup2(pu_pipe[1], 1);
+               dup2(pe_pipe[1], 2);
+
+               close(lp_pipe[0]);
+               close(lp_pipe[1]);
+               close(pu_pipe[0]);
+               close(pu_pipe[1]);
+               close(pe_pipe[0]);
+               close(pe_pipe[1]);
+               execl_git_cmd("pack-objects", "--stdout", "--progress",
+                             use_ofs_delta ? "--delta-base-offset" : NULL,
+                             NULL);
+               kill(pid_rev_list, SIGKILL);
+               die("git-upload-pack: unable to exec git-pack-objects");
+       }
+
+       close(lp_pipe[0]);
+       close(lp_pipe[1]);
+
+       /* We read from pe_pipe[0] to capture stderr output for
+        * progress bar, and pu_pipe[0] to capture the pack data.
+        */
+       close(pe_pipe[1]);
+       close(pu_pipe[1]);
+
+       while (1) {
+               const char *who;
+               struct pollfd pfd[2];
+               pid_t pid;
+               int status;
+               ssize_t sz;
+               int pe, pu, pollsize;
+
+               reset_timeout();
+
+               pollsize = 0;
+               pe = pu = -1;
+
+               if (0 <= pu_pipe[0]) {
+                       pfd[pollsize].fd = pu_pipe[0];
+                       pfd[pollsize].events = POLLIN;
+                       pu = pollsize;
+                       pollsize++;
+               }
+               if (0 <= pe_pipe[0]) {
+                       pfd[pollsize].fd = pe_pipe[0];
+                       pfd[pollsize].events = POLLIN;
+                       pe = pollsize;
+                       pollsize++;
+               }
+
+               if (pollsize) {
+                       if (poll(pfd, pollsize, -1) < 0) {
+                               if (errno != EINTR) {
+                                       error("poll failed, resuming: %s",
+                                             strerror(errno));
+                                       sleep(1);
+                               }
+                               continue;
+                       }
+                       if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
+                               /* Data ready; we keep the last byte
+                                * to ourselves in case we detect
+                                * broken rev-list, so that we can
+                                * leave the stream corrupted.  This
+                                * is unfortunate -- unpack-objects
+                                * would happily accept a valid pack
+                                * data with trailing garbage, so
+                                * appending garbage after we pass all
+                                * the pack data is not good enough to
+                                * signal breakage to downstream.
+                                */
+                               char *cp = data;
+                               ssize_t outsz = 0;
+                               if (0 <= buffered) {
+                                       *cp++ = buffered;
+                                       outsz++;
+                               }
+                               sz = xread(pu_pipe[0], cp,
+                                         sizeof(data) - outsz);
+                               if (0 < sz)
+                                               ;
+                               else if (sz == 0) {
+                                       close(pu_pipe[0]);
+                                       pu_pipe[0] = -1;
+                               }
+                               else
+                                       goto fail;
+                               sz += outsz;
+                               if (1 < sz) {
+                                       buffered = data[sz-1] & 0xFF;
+                                       sz--;
+                               }
+                               else
+                                       buffered = -1;
+                               sz = send_client_data(1, data, sz);
+                               if (sz < 0)
+                                       goto fail;
+                       }
+                       if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
+                               /* Status ready; we ship that in the side-band
+                                * or dump to the standard error.
+                                */
+                               sz = xread(pe_pipe[0], progress,
+                                         sizeof(progress));
+                               if (0 < sz)
+                                       send_client_data(2, progress, sz);
+                               else if (sz == 0) {
+                                       close(pe_pipe[0]);
+                                       pe_pipe[0] = -1;
+                               }
+                               else
+                                       goto fail;
                        }
                }
-               if (!create_full_pack)
-                       for (i = 0; i < nr_has; i++) {
-                               *p++ = buf;
-                               *buf++ = '^';
-                               memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
-                               buf += 41;
+
+               /* See if the children are still there */
+               if (pid_rev_list || pid_pack_objects) {
+                       pid = waitpid(-1, &status, WNOHANG);
+                       if (!pid)
+                               continue;
+                       who = ((pid == pid_rev_list) ? "git-rev-list" :
+                              (pid == pid_pack_objects) ? "git-pack-objects" :
+                              NULL);
+                       if (!who) {
+                               if (pid < 0) {
+                                       error("git-upload-pack: %s",
+                                             strerror(errno));
+                                       goto fail;
+                               }
+                               error("git-upload-pack: we weren't "
+                                     "waiting for %d", pid);
+                               continue;
+                       }
+                       if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
+                               error("git-upload-pack: %s died with error.",
+                                     who);
+                               goto fail;
                        }
-               *p++ = NULL;
-               execv_git_cmd(argv);
-               die("git-upload-pack: unable to exec git-rev-list");
+                       if (pid == pid_rev_list)
+                               pid_rev_list = 0;
+                       if (pid == pid_pack_objects)
+                               pid_pack_objects = 0;
+                       if (pid_rev_list || pid_pack_objects)
+                               continue;
+               }
+
+               /* both died happily */
+               if (pollsize)
+                       continue;
+
+               /* flush the data */
+               if (0 <= buffered) {
+                       data[0] = buffered;
+                       sz = send_client_data(1, data, 1);
+                       if (sz < 0)
+                               goto fail;
+                       fprintf(stderr, "flushed.\n");
+               }
+               if (use_sideband)
+                       packet_flush(1);
+               return;
        }
-       dup2(fd[0], 0);
-       close(fd[0]);
-       close(fd[1]);
-       execl_git_cmd("pack-objects", "--stdout", NULL);
-       die("git-upload-pack: unable to exec git-pack-objects");
+ fail:
+       if (pid_pack_objects)
+               kill(pid_pack_objects, SIGKILL);
+       if (pid_rev_list)
+               kill(pid_rev_list, SIGKILL);
+       send_client_data(3, abort_msg, sizeof(abort_msg));
+       die("git-upload-pack: %s", abort_msg);
 }
 
 static int got_sha1(char *hex, unsigned char *sha1)
 {
+       struct object *o;
+       int we_knew_they_have = 0;
+
        if (get_sha1_hex(hex, sha1))
                die("git-upload-pack: expected SHA1 object, got '%s'", hex);
        if (!has_sha1_file(sha1))
-               return 0;
-       if (nr_has < MAX_HAS) {
-               struct object *o = lookup_object(sha1);
-               if (!(o && o->parsed))
-                       o = parse_object(sha1);
-               if (!o)
-                       die("oops (%s)", sha1_to_hex(sha1));
-               if (o->type == commit_type) {
-                       struct commit_list *parents;
-                       if (o->flags & THEY_HAVE)
-                               return 0;
+               return -1;
+
+       o = lookup_object(sha1);
+       if (!(o && o->parsed))
+               o = parse_object(sha1);
+       if (!o)
+               die("oops (%s)", sha1_to_hex(sha1));
+       if (o->type == OBJ_COMMIT) {
+               struct commit_list *parents;
+               struct commit *commit = (struct commit *)o;
+               if (o->flags & THEY_HAVE)
+                       we_knew_they_have = 1;
+               else
                        o->flags |= THEY_HAVE;
-                       for (parents = ((struct commit*)o)->parents;
-                            parents;
-                            parents = parents->next)
-                               parents->item->object.flags |= THEY_HAVE;
+               if (!oldest_have || (commit->date < oldest_have))
+                       oldest_have = commit->date;
+               for (parents = commit->parents;
+                    parents;
+                    parents = parents->next)
+                       parents->item->object.flags |= THEY_HAVE;
+       }
+       if (!we_knew_they_have) {
+               add_object_array(o, NULL, &have_obj);
+               return 1;
+       }
+       return 0;
+}
+
+static int reachable(struct commit *want)
+{
+       struct commit_list *work = NULL;
+
+       insert_by_date(want, &work);
+       while (work) {
+               struct commit_list *list = work->next;
+               struct commit *commit = work->item;
+               free(work);
+               work = list;
+
+               if (commit->object.flags & THEY_HAVE) {
+                       want->object.flags |= COMMON_KNOWN;
+                       break;
+               }
+               if (!commit->object.parsed)
+                       parse_object(commit->object.sha1);
+               if (commit->object.flags & REACHABLE)
+                       continue;
+               commit->object.flags |= REACHABLE;
+               if (commit->date < oldest_have)
+                       continue;
+               for (list = commit->parents; list; list = list->next) {
+                       struct commit *parent = list->item;
+                       if (!(parent->object.flags & REACHABLE))
+                               insert_by_date(parent, &work);
                }
-               memcpy(has_sha1[nr_has++], sha1, 20);
+       }
+       want->object.flags |= REACHABLE;
+       clear_commit_marks(want, REACHABLE);
+       free_commit_list(work);
+       return (want->object.flags & COMMON_KNOWN);
+}
+
+static int ok_to_give_up(void)
+{
+       int i;
+
+       if (!have_obj.nr)
+               return 0;
+
+       for (i = 0; i < want_obj.nr; i++) {
+               struct object *want = want_obj.objects[i].item;
+
+               if (want->flags & COMMON_KNOWN)
+                       continue;
+               want = deref_tag(want, "a want line", 0);
+               if (!want || want->type != OBJ_COMMIT) {
+                       /* no way to tell if this is reachable by
+                        * looking at the ancestry chain alone, so
+                        * leave a note to ourselves not to worry about
+                        * this object anymore.
+                        */
+                       want_obj.objects[i].item->flags |= COMMON_KNOWN;
+                       continue;
+               }
+               if (!reachable((struct commit *)want))
+                       return 0;
        }
        return 1;
 }
@@ -123,7 +438,8 @@ static int got_sha1(char *hex, unsigned char *sha1)
 static int get_common_commits(void)
 {
        static char line[1000];
-       unsigned char sha1[20], last_sha1[20];
+       unsigned char sha1[20];
+       char hex[41], last_hex[41];
        int len;
 
        track_object_refs = 0;
@@ -134,29 +450,35 @@ static int get_common_commits(void)
                reset_timeout();
 
                if (!len) {
-                       if (nr_has == 0 || multi_ack)
+                       if (have_obj.nr == 0 || multi_ack)
                                packet_write(1, "NAK\n");
                        continue;
                }
                len = strip(line, len);
                if (!strncmp(line, "have ", 5)) {
-                       if (got_sha1(line+5, sha1) &&
-                                       (multi_ack || nr_has == 1)) {
-                               if (nr_has >= MAX_HAS)
-                                       multi_ack = 0;
-                               packet_write(1, "ACK %s%s\n",
-                                       sha1_to_hex(sha1),
-                                       multi_ack ?  " continue" : "");
-                               if (multi_ack)
-                                       memcpy(last_sha1, sha1, 20);
+                       switch (got_sha1(line+5, sha1)) {
+                       case -1: /* they have what we do not */
+                               if (multi_ack && ok_to_give_up())
+                                       packet_write(1, "ACK %s continue\n",
+                                                    sha1_to_hex(sha1));
+                               break;
+                       default:
+                               memcpy(hex, sha1_to_hex(sha1), 41);
+                               if (multi_ack) {
+                                       const char *msg = "ACK %s continue\n";
+                                       packet_write(1, msg, hex);
+                                       memcpy(last_hex, hex, 41);
+                               }
+                               else if (have_obj.nr == 1)
+                                       packet_write(1, "ACK %s\n", hex);
+                               break;
                        }
                        continue;
                }
                if (!strcmp(line, "done")) {
-                       if (nr_has > 0) {
+                       if (have_obj.nr > 0) {
                                if (multi_ack)
-                                       packet_write(1, "ACK %s\n",
-                                                       sha1_to_hex(last_sha1));
+                                       packet_write(1, "ACK %s\n", last_hex);
                                return 0;
                        }
                        packet_write(1, "NAK\n");
@@ -166,37 +488,55 @@ static int get_common_commits(void)
        }
 }
 
-static int receive_needs(void)
+static void receive_needs(void)
 {
+       struct object_array shallows = {0, 0, NULL};
        static char line[1000];
-       int len, needs;
+       int len, depth = 0;
 
-       needs = 0;
        for (;;) {
                struct object *o;
-               unsigned char dummy[20], *sha1_buf;
+               unsigned char sha1_buf[20];
                len = packet_read_line(0, line, sizeof(line));
                reset_timeout();
                if (!len)
-                       return needs;
-
-               sha1_buf = dummy;
-               if (needs == MAX_NEEDS) {
-                       fprintf(stderr,
-                               "warning: supporting only a max of %d requests. "
-                               "sending everything instead.\n",
-                               MAX_NEEDS);
-               }
-               else if (needs < MAX_NEEDS)
-                       sha1_buf = needs_sha1[needs];
+                       break;
 
-               if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
+               if (!strncmp("shallow ", line, 8)) {
+                       unsigned char sha1[20];
+                       struct object *object;
+                       use_thin_pack = 0;
+                       if (get_sha1(line + 8, sha1))
+                               die("invalid shallow line: %s", line);
+                       object = parse_object(sha1);
+                       if (!object)
+                               die("did not find object for %s", line);
+                       object->flags |= CLIENT_SHALLOW;
+                       add_object_array(object, NULL, &shallows);
+                       continue;
+               }
+               if (!strncmp("deepen ", line, 7)) {
+                       char *end;
+                       use_thin_pack = 0;
+                       depth = strtol(line + 7, &end, 0);
+                       if (end == line + 7 || depth <= 0)
+                               die("Invalid deepen: %s", line);
+                       continue;
+               }
+               if (strncmp("want ", line, 5) ||
+                   get_sha1_hex(line+5, sha1_buf))
                        die("git-upload-pack: protocol error, "
                            "expected to get sha, not '%s'", line);
                if (strstr(line+45, "multi_ack"))
                        multi_ack = 1;
                if (strstr(line+45, "thin-pack"))
                        use_thin_pack = 1;
+               if (strstr(line+45, "ofs-delta"))
+                       use_ofs_delta = 1;
+               if (strstr(line+45, "side-band-64k"))
+                       use_sideband = LARGE_PACKET_MAX;
+               else if (strstr(line+45, "side-band"))
+                       use_sideband = DEFAULT_PACKET_MAX;
 
                /* We have sent all our refs already, and the other end
                 * should have chosen out of them; otherwise they are
@@ -211,14 +551,61 @@ static int receive_needs(void)
                        die("git-upload-pack: not our ref %s", line+5);
                if (!(o->flags & WANTED)) {
                        o->flags |= WANTED;
-                       needs++;
+                       add_object_array(o, NULL, &want_obj);
                }
        }
+       if (depth == 0 && shallows.nr == 0)
+               return;
+       if (depth > 0) {
+               struct commit_list *result, *backup;
+               int i;
+               backup = result = get_shallow_commits(&want_obj, depth,
+                       SHALLOW, NOT_SHALLOW);
+               while (result) {
+                       struct object *object = &result->item->object;
+                       if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
+                               packet_write(1, "shallow %s",
+                                               sha1_to_hex(object->sha1));
+                               register_shallow(object->sha1);
+                       }
+                       result = result->next;
+               }
+               free_commit_list(backup);
+               for (i = 0; i < shallows.nr; i++) {
+                       struct object *object = shallows.objects[i].item;
+                       if (object->flags & NOT_SHALLOW) {
+                               struct commit_list *parents;
+                               packet_write(1, "unshallow %s",
+                                       sha1_to_hex(object->sha1));
+                               object->flags &= ~CLIENT_SHALLOW;
+                               /* make sure the real parents are parsed */
+                               unregister_shallow(object->sha1);
+                               object->parsed = 0;
+                               parse_commit((struct commit *)object);
+                               parents = ((struct commit *)object)->parents;
+                               while (parents) {
+                                       add_object_array(&parents->item->object,
+                                                       NULL, &want_obj);
+                                       parents = parents->next;
+                               }
+                       }
+                       /* make sure commit traversal conforms to client */
+                       register_shallow(object->sha1);
+               }
+               packet_flush(1);
+       } else
+               if (shallows.nr > 0) {
+                       int i;
+                       for (i = 0; i < shallows.nr; i++)
+                               register_shallow(shallows.objects[i].item->sha1);
+               }
+       free(shallows.objects);
 }
 
-static int send_ref(const char *refname, const unsigned char *sha1)
+static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
-       static char *capabilities = "multi_ack thin-pack";
+       static const char *capabilities = "multi_ack thin-pack side-band"
+               " side-band-64k ofs-delta shallow";
        struct object *o = parse_object(sha1);
 
        if (!o)
@@ -234,25 +621,24 @@ static int send_ref(const char *refname, const unsigned char *sha1)
                o->flags |= OUR_REF;
                nr_our_refs++;
        }
-       if (o->type == tag_type) {
+       if (o->type == OBJ_TAG) {
                o = deref_tag(o, refname, 0);
                packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
        }
        return 0;
 }
 
-static int upload_pack(void)
+static void upload_pack(void)
 {
        reset_timeout();
-       head_ref(send_ref);
-       for_each_ref(send_ref);
+       head_ref(send_ref, NULL);
+       for_each_ref(send_ref, NULL);
        packet_flush(1);
-       nr_needs = receive_needs();
-       if (!nr_needs)
-               return 0;
-       get_common_commits();
-       create_pack_file();
-       return 0;
+       receive_needs();
+       if (want_obj.nr) {
+               get_common_commits();
+               create_pack_file();
+       }
 }
 
 int main(int argc, char **argv)
@@ -286,7 +672,8 @@ int main(int argc, char **argv)
 
        if (!enter_repo(dir, strict))
                die("'%s': unable to chdir or not a git archive", dir);
-
+       if (is_repository_shallow())
+               die("attempt to fetch/clone from a shallow repository");
        upload_pack();
        return 0;
 }