Merge branch 'jc/upload-pack-send-symref' into maint
authorJunio C Hamano <gitster@pobox.com>
Fri, 8 Nov 2013 19:38:00 +0000 (11:38 -0800)
committerJunio C Hamano <gitster@pobox.com>
Fri, 8 Nov 2013 19:38:00 +0000 (11:38 -0800)
One long-standing flaw in the pack transfer protocol used by "git
clone" was that there was no way to tell the other end which branch
"HEAD" points at, and the receiving end needed to guess. A new
capability has been defined in the pack protocol to convey this
information so that cloning from a repository with more than one
branches pointing at the same commit where the HEAD is at now
reliably sets the initial branch in the resulting repository.

* jc/upload-pack-send-symref:
t5570: Update for clone-progress-to-stderr branch
t5570: Update for symref capability
clone: test the new HEAD detection logic
connect: annotate refs with their symref information in get_remote_head()
connect.c: make parse_feature_value() static
upload-pack: send non-HEAD symbolic refs
upload-pack: send symbolic ref information as capability
upload-pack.c: do not pass confusing cb_data to mark_our_ref()
t5505: fix "set-head --auto with ambiguous HEAD" test

1  2 
cache.h
upload-pack.c
diff --combined cache.h
index 88d373dfe729ef20cec73ee9e20b8b0975e22b6c,2c853ba856110ab09c6dbbaf2f07a49f4fde92d9..415d8830809cbb8a9651004184a01315ee8c7c3e
+++ b/cache.h
@@@ -966,15 -966,6 +966,15 @@@ struct ident_split 
   */
  extern int split_ident_line(struct ident_split *, const char *, int);
  
 +/*
 + * Compare split idents for equality or strict ordering. Note that we
 + * compare only the ident part of the line, ignoring any timestamp.
 + *
 + * Because there are two fields, we must choose one as the primary key; we
 + * currently arbitrarily pick the email.
 + */
 +extern int ident_cmp(const struct ident_split *, const struct ident_split *);
 +
  struct checkout {
        const char *base_dir;
        int base_dir_len;
@@@ -1107,7 -1098,6 +1107,6 @@@ extern struct ref **get_remote_heads(in
  extern int server_supports(const char *feature);
  extern int parse_feature_request(const char *features, const char *feature);
  extern const char *server_feature_value(const char *feature, int *len_ret);
- extern const char *parse_feature_value(const char *feature_list, const char *feature, int *len_ret);
  
  extern struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path);
  
diff --combined upload-pack.c
index 8327dc0b7c80b61fc24342a1816e323009818729,2826909eba69977caa783340c6a3a5290670e015..fd96f3be116fa3655d8a0f297bcd6c6c4fec5cb7
@@@ -40,7 -40,6 +40,7 @@@ static struct object_array have_obj
  static struct object_array want_obj;
  static struct object_array extra_edge_obj;
  static unsigned int timeout;
 +static int keepalive = 5;
  /* 0 for no sideband,
   * otherwise maximum packet size (up to 65520 bytes).
   */
@@@ -69,28 -68,87 +69,28 @@@ static ssize_t send_client_data(int fd
        return sz;
  }
  
 -static FILE *pack_pipe = NULL;
 -static void show_commit(struct commit *commit, void *data)
 -{
 -      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 *obj,
 -                      const struct name_path *path, const char *component,
 -                      void *cb_data)
 -{
 -      show_object_with_name(pack_pipe, obj, path, component);
 -}
 -
 -static void show_edge(struct commit *commit)
 -{
 -      fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
 -}
 -
 -static int do_rev_list(int in, int out, void *user_data)
 -{
 -      int i;
 -      struct rev_info revs;
 -
 -      pack_pipe = xfdopen(out, "w");
 -      init_revisions(&revs, NULL);
 -      revs.tag_objects = 1;
 -      revs.tree_objects = 1;
 -      revs.blob_objects = 1;
 -      if (use_thin_pack)
 -              revs.edge_hint = 1;
 -
 -      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);
 -      if (prepare_revision_walk(&revs))
 -              die("revision walk setup failed");
 -      mark_edges_uninteresting(revs.commits, &revs, show_edge);
 -      if (use_thin_pack)
 -              for (i = 0; i < extra_edge_obj.nr; i++)
 -                      fprintf(pack_pipe, "-%s\n", sha1_to_hex(
 -                                      extra_edge_obj.objects[i].item->sha1));
 -      traverse_commit_list(&revs, show_commit, show_object, NULL);
 -      fflush(pack_pipe);
 -      fclose(pack_pipe);
 -      return 0;
 -}
 -
  static void create_pack_file(void)
  {
 -      struct async rev_list;
        struct child_process pack_objects;
        char data[8193], progress[128];
        char abort_msg[] = "aborting due to possible repository "
                "corruption on the remote side.";
        int buffered = -1;
        ssize_t sz;
 -      const char *argv[10];
 -      int arg = 0;
 +      const char *argv[12];
 +      int i, arg = 0;
 +      FILE *pipe_fd;
 +      char *shallow_file = NULL;
  
 -      argv[arg++] = "pack-objects";
 -      if (!shallow_nr) {
 -              argv[arg++] = "--revs";
 -              if (use_thin_pack)
 -                      argv[arg++] = "--thin";
 +      if (shallow_nr) {
 +              shallow_file = setup_temporary_shallow();
 +              argv[arg++] = "--shallow-file";
 +              argv[arg++] = shallow_file;
        }
 +      argv[arg++] = "pack-objects";
 +      argv[arg++] = "--revs";
 +      if (use_thin_pack)
 +              argv[arg++] = "--thin";
  
        argv[arg++] = "--stdout";
        if (!no_progress)
        if (start_command(&pack_objects))
                die("git upload-pack: unable to fork git-pack-objects");
  
 -      if (shallow_nr) {
 -              memset(&rev_list, 0, sizeof(rev_list));
 -              rev_list.proc = do_rev_list;
 -              rev_list.out = pack_objects.in;
 -              if (start_async(&rev_list))
 -                      die("git upload-pack: unable to fork git-rev-list");
 -      }
 -      else {
 -              FILE *pipe_fd = xfdopen(pack_objects.in, "w");
 -              int i;
 -
 -              for (i = 0; i < want_obj.nr; i++)
 -                      fprintf(pipe_fd, "%s\n",
 -                              sha1_to_hex(want_obj.objects[i].item->sha1));
 -              fprintf(pipe_fd, "--not\n");
 -              for (i = 0; i < have_obj.nr; i++)
 -                      fprintf(pipe_fd, "%s\n",
 -                              sha1_to_hex(have_obj.objects[i].item->sha1));
 -              fprintf(pipe_fd, "\n");
 -              fflush(pipe_fd);
 -              fclose(pipe_fd);
 -      }
 -
 +      pipe_fd = xfdopen(pack_objects.in, "w");
 +
 +      for (i = 0; i < want_obj.nr; i++)
 +              fprintf(pipe_fd, "%s\n",
 +                      sha1_to_hex(want_obj.objects[i].item->sha1));
 +      fprintf(pipe_fd, "--not\n");
 +      for (i = 0; i < have_obj.nr; i++)
 +              fprintf(pipe_fd, "%s\n",
 +                      sha1_to_hex(have_obj.objects[i].item->sha1));
 +      for (i = 0; i < extra_edge_obj.nr; i++)
 +              fprintf(pipe_fd, "%s\n",
 +                      sha1_to_hex(extra_edge_obj.objects[i].item->sha1));
 +      fprintf(pipe_fd, "\n");
 +      fflush(pipe_fd);
 +      fclose(pipe_fd);
  
        /* We read from pack_objects.err to capture stderr output for
         * progress bar, and pack_objects.out to capture the pack data.
        while (1) {
                struct pollfd pfd[2];
                int pe, pu, pollsize;
 +              int ret;
  
                reset_timeout();
  
                if (!pollsize)
                        break;
  
 -              if (poll(pfd, pollsize, -1) < 0) {
 +              ret = poll(pfd, pollsize, 1000 * keepalive);
 +              if (ret < 0) {
                        if (errno != EINTR) {
                                error("poll failed, resuming: %s",
                                      strerror(errno));
                        if (sz < 0)
                                goto fail;
                }
 +
 +              /*
 +               * We hit the keepalive timeout without saying anything; send
 +               * an empty message on the data sideband just to let the other
 +               * side know we're still working on it, but don't have any data
 +               * yet.
 +               *
 +               * If we don't have a sideband channel, there's no room in the
 +               * protocol to say anything, so those clients are just out of
 +               * luck.
 +               */
 +              if (!ret && use_sideband) {
 +                      static const char buf[] = "0005\1";
 +                      write_or_die(1, buf, 5);
 +              }
        }
  
        if (finish_command(&pack_objects)) {
                error("git upload-pack: git-pack-objects died with error.");
                goto fail;
        }
 -      if (shallow_nr && finish_async(&rev_list))
 -              goto fail;      /* error was already reported */
 +      if (shallow_file) {
 +              if (*shallow_file)
 +                      unlink(shallow_file);
 +              free(shallow_file);
 +      }
  
        /* flush the data */
        if (0 <= buffered) {
@@@ -688,6 -734,16 +688,16 @@@ static int mark_our_ref(const char *ref
        return 0;
  }
  
+ static void format_symref_info(struct strbuf *buf, struct string_list *symref)
+ {
+       struct string_list_item *item;
+       if (!symref->nr)
+               return;
+       for_each_string_list_item(item, symref)
+               strbuf_addf(buf, " symref=%s:%s", item->string, (char *)item->util);
+ }
  static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
  {
        static const char *capabilities = "multi_ack thin-pack side-band"
        const char *refname_nons = strip_namespace(refname);
        unsigned char peeled[20];
  
-       if (mark_our_ref(refname, sha1, flag, cb_data))
+       if (mark_our_ref(refname, sha1, flag, NULL))
                return 0;
  
-       if (capabilities)
-               packet_write(1, "%s %s%c%s%s%s agent=%s\n",
+       if (capabilities) {
+               struct strbuf symref_info = STRBUF_INIT;
+               format_symref_info(&symref_info, cb_data);
+               packet_write(1, "%s %s%c%s%s%s%s agent=%s\n",
                             sha1_to_hex(sha1), refname_nons,
                             0, capabilities,
                             allow_tip_sha1_in_want ? " allow-tip-sha1-in-want" : "",
                             stateless_rpc ? " no-done" : "",
+                            symref_info.buf,
                             git_user_agent_sanitized());
-       else
+               strbuf_release(&symref_info);
+       } else {
                packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname_nons);
+       }
        capabilities = NULL;
        if (!peel_ref(refname, peeled))
                packet_write(1, "%s %s^{}\n", sha1_to_hex(peeled), refname_nons);
        return 0;
  }
  
+ static int find_symref(const char *refname, const unsigned char *sha1, int flag,
+                      void *cb_data)
+ {
+       const char *symref_target;
+       struct string_list_item *item;
+       unsigned char unused[20];
+       if ((flag & REF_ISSYMREF) == 0)
+               return 0;
+       symref_target = resolve_ref_unsafe(refname, unused, 0, &flag);
+       if (!symref_target || (flag & REF_ISSYMREF) == 0)
+               die("'%s' is a symref but it is not?", refname);
+       item = string_list_append(cb_data, refname);
+       item->util = xstrdup(symref_target);
+       return 0;
+ }
  static void upload_pack(void)
  {
+       struct string_list symref = STRING_LIST_INIT_DUP;
+       head_ref_namespaced(find_symref, &symref);
+       for_each_namespaced_ref(find_symref, &symref);
        if (advertise_refs || !stateless_rpc) {
                reset_timeout();
-               head_ref_namespaced(send_ref, NULL);
-               for_each_namespaced_ref(send_ref, NULL);
+               head_ref_namespaced(send_ref, &symref);
+               for_each_namespaced_ref(send_ref, &symref);
                packet_flush(1);
        } else {
                head_ref_namespaced(mark_our_ref, NULL);
                for_each_namespaced_ref(mark_our_ref, NULL);
        }
+       string_list_clear(&symref, 1);
        if (advertise_refs)
                return;
  
@@@ -739,11 -824,6 +778,11 @@@ static int upload_pack_config(const cha
  {
        if (!strcmp("uploadpack.allowtipsha1inwant", var))
                allow_tip_sha1_in_want = git_config_bool(var, value);
 +      else if (!strcmp("uploadpack.keepalive", var)) {
 +              keepalive = git_config_int(var, value);
 +              if (!keepalive)
 +                      keepalive = -1;
 +      }
        return parse_hide_refs_config(var, value, "uploadpack");
  }