i18n: git-add "Unstaged changes" message
[gitweb.git] / transport-helper.c
index f57e84c67641b5a03ba8d9ed5182507bb54dcd15..4e4754c32bd53f28f9335c2a4529f5804f3086f2 100644 (file)
 #include "cache.h"
 #include "transport.h"
-
+#include "quote.h"
 #include "run-command.h"
 #include "commit.h"
 #include "diff.h"
 #include "revision.h"
+#include "quote.h"
+#include "remote.h"
+#include "string-list.h"
+#include "thread-utils.h"
+
+static int debug;
 
 struct helper_data
 {
        const char *name;
        struct child_process *helper;
-       unsigned fetch : 1;
+       FILE *out;
+       unsigned fetch : 1,
+               import : 1,
+               export : 1,
+               option : 1,
+               push : 1,
+               connect : 1,
+               no_disconnect_req : 1;
+       /* These go from remote name (as in "list") to private name */
+       struct refspec *refspecs;
+       int refspec_nr;
+       /* Transport options for fetch-pack/send-pack (should one of
+        * those be invoked).
+        */
+       struct git_transport_options transport_options;
 };
 
+static void sendline(struct helper_data *helper, struct strbuf *buffer)
+{
+       if (debug)
+               fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
+       if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
+               != buffer->len)
+               die_errno("Full write to remote helper failed");
+}
+
+static int recvline_fh(FILE *helper, struct strbuf *buffer)
+{
+       strbuf_reset(buffer);
+       if (debug)
+               fprintf(stderr, "Debug: Remote helper: Waiting...\n");
+       if (strbuf_getline(buffer, helper, '\n') == EOF) {
+               if (debug)
+                       fprintf(stderr, "Debug: Remote helper quit.\n");
+               exit(128);
+       }
+
+       if (debug)
+               fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
+       return 0;
+}
+
+static int recvline(struct helper_data *helper, struct strbuf *buffer)
+{
+       return recvline_fh(helper->out, buffer);
+}
+
+static void xchgline(struct helper_data *helper, struct strbuf *buffer)
+{
+       sendline(helper, buffer);
+       recvline(helper, buffer);
+}
+
+static void write_constant(int fd, const char *str)
+{
+       if (debug)
+               fprintf(stderr, "Debug: Remote helper: -> %s", str);
+       if (write_in_full(fd, str, strlen(str)) != strlen(str))
+               die_errno("Full write to remote helper failed");
+}
+
+const char *remove_ext_force(const char *url)
+{
+       if (url) {
+               const char *colon = strchr(url, ':');
+               if (colon && colon[1] == ':')
+                       return colon + 2;
+       }
+       return url;
+}
+
+static void do_take_over(struct transport *transport)
+{
+       struct helper_data *data;
+       data = (struct helper_data *)transport->data;
+       transport_take_over(transport, data->helper);
+       fclose(data->out);
+       free(data);
+}
+
 static struct child_process *get_helper(struct transport *transport)
 {
        struct helper_data *data = transport->data;
        struct strbuf buf = STRBUF_INIT;
        struct child_process *helper;
-       FILE *file;
+       const char **refspecs = NULL;
+       int refspec_nr = 0;
+       int refspec_alloc = 0;
+       int duped;
+       int code;
 
        if (data->helper)
                return data->helper;
@@ -28,36 +115,107 @@ static struct child_process *get_helper(struct transport *transport)
        helper->out = -1;
        helper->err = 0;
        helper->argv = xcalloc(4, sizeof(*helper->argv));
-       strbuf_addf(&buf, "remote-%s", data->name);
+       strbuf_addf(&buf, "git-remote-%s", data->name);
        helper->argv[0] = strbuf_detach(&buf, NULL);
        helper->argv[1] = transport->remote->name;
-       helper->argv[2] = transport->url;
-       helper->git_cmd = 1;
-       if (start_command(helper))
-               die("Unable to run helper: git %s", helper->argv[0]);
+       helper->argv[2] = remove_ext_force(transport->url);
+       helper->git_cmd = 0;
+       helper->silent_exec_failure = 1;
+       code = start_command(helper);
+       if (code < 0 && errno == ENOENT)
+               die("Unable to find remote helper for '%s'", data->name);
+       else if (code != 0)
+               exit(code);
+
        data->helper = helper;
+       data->no_disconnect_req = 0;
 
-       write_str_in_full(helper->in, "capabilities\n");
+       /*
+        * Open the output as FILE* so strbuf_getline() can be used.
+        * Do this with duped fd because fclose() will close the fd,
+        * and stuff like taking over will require the fd to remain.
+        */
+       duped = dup(helper->out);
+       if (duped < 0)
+               die_errno("Can't dup helper output fd");
+       data->out = xfdopen(duped, "r");
+
+       write_constant(helper->in, "capabilities\n");
 
-       file = xfdopen(helper->out, "r");
        while (1) {
-               if (strbuf_getline(&buf, file, '\n') == EOF)
-                       exit(128); /* child died, message supplied already */
+               const char *capname;
+               int mandatory = 0;
+               recvline(data, &buf);
 
                if (!*buf.buf)
                        break;
-               if (!strcmp(buf.buf, "fetch"))
+
+               if (*buf.buf == '*') {
+                       capname = buf.buf + 1;
+                       mandatory = 1;
+               } else
+                       capname = buf.buf;
+
+               if (debug)
+                       fprintf(stderr, "Debug: Got cap %s\n", capname);
+               if (!strcmp(capname, "fetch"))
                        data->fetch = 1;
+               else if (!strcmp(capname, "option"))
+                       data->option = 1;
+               else if (!strcmp(capname, "push"))
+                       data->push = 1;
+               else if (!strcmp(capname, "import"))
+                       data->import = 1;
+               else if (!strcmp(capname, "export"))
+                       data->export = 1;
+               else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
+                       ALLOC_GROW(refspecs,
+                                  refspec_nr + 1,
+                                  refspec_alloc);
+                       refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
+               } else if (!strcmp(capname, "connect")) {
+                       data->connect = 1;
+               } else if (!strcmp(buf.buf, "gitdir")) {
+                       struct strbuf gitdir = STRBUF_INIT;
+                       strbuf_addf(&gitdir, "gitdir %s\n", get_git_dir());
+                       sendline(data, &gitdir);
+                       strbuf_release(&gitdir);
+               } else if (mandatory) {
+                       die("Unknown mandatory capability %s. This remote "
+                           "helper probably needs newer version of Git.\n",
+                           capname);
+               }
        }
+       if (refspecs) {
+               int i;
+               data->refspec_nr = refspec_nr;
+               data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
+               for (i = 0; i < refspec_nr; i++) {
+                       free((char *)refspecs[i]);
+               }
+               free(refspecs);
+       }
+       strbuf_release(&buf);
+       if (debug)
+               fprintf(stderr, "Debug: Capabilities complete.\n");
        return data->helper;
 }
 
 static int disconnect_helper(struct transport *transport)
 {
        struct helper_data *data = transport->data;
+       struct strbuf buf = STRBUF_INIT;
+
        if (data->helper) {
-               write_str_in_full(data->helper->in, "\n");
+               if (debug)
+                       fprintf(stderr, "Debug: Disconnecting.\n");
+               if (!data->no_disconnect_req) {
+                       strbuf_addf(&buf, "\n");
+                       sendline(data, &buf);
+               }
                close(data->helper->in);
+               close(data->helper->out);
+               fclose(data->out);
                finish_command(data->helper);
                free((char *)data->helper->argv[0]);
                free(data->helper->argv);
@@ -67,14 +225,98 @@ static int disconnect_helper(struct transport *transport)
        return 0;
 }
 
+static const char *unsupported_options[] = {
+       TRANS_OPT_UPLOADPACK,
+       TRANS_OPT_RECEIVEPACK,
+       TRANS_OPT_THIN,
+       TRANS_OPT_KEEP
+       };
+static const char *boolean_options[] = {
+       TRANS_OPT_THIN,
+       TRANS_OPT_KEEP,
+       TRANS_OPT_FOLLOWTAGS
+       };
+
+static int set_helper_option(struct transport *transport,
+                         const char *name, const char *value)
+{
+       struct helper_data *data = transport->data;
+       struct strbuf buf = STRBUF_INIT;
+       int i, ret, is_bool = 0;
+
+       get_helper(transport);
+
+       if (!data->option)
+               return 1;
+
+       for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
+               if (!strcmp(name, unsupported_options[i]))
+                       return 1;
+       }
+
+       for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
+               if (!strcmp(name, boolean_options[i])) {
+                       is_bool = 1;
+                       break;
+               }
+       }
+
+       strbuf_addf(&buf, "option %s ", name);
+       if (is_bool)
+               strbuf_addstr(&buf, value ? "true" : "false");
+       else
+               quote_c_style(value, &buf, NULL, 0);
+       strbuf_addch(&buf, '\n');
+
+       xchgline(data, &buf);
+
+       if (!strcmp(buf.buf, "ok"))
+               ret = 0;
+       else if (!prefixcmp(buf.buf, "error")) {
+               ret = -1;
+       } else if (!strcmp(buf.buf, "unsupported"))
+               ret = 1;
+       else {
+               warning("%s unexpectedly said: '%s'", data->name, buf.buf);
+               ret = 1;
+       }
+       strbuf_release(&buf);
+       return ret;
+}
+
+static void standard_options(struct transport *t)
+{
+       char buf[16];
+       int n;
+       int v = t->verbose;
+
+       set_helper_option(t, "progress", t->progress ? "true" : "false");
+
+       n = snprintf(buf, sizeof(buf), "%d", v + 1);
+       if (n >= sizeof(buf))
+               die("impossibly large verbosity value");
+       set_helper_option(t, "verbosity", buf);
+}
+
+static int release_helper(struct transport *transport)
+{
+       struct helper_data *data = transport->data;
+       free_refspec(data->refspec_nr, data->refspecs);
+       data->refspecs = NULL;
+       disconnect_helper(transport);
+       free(transport->data);
+       return 0;
+}
+
 static int fetch_with_fetch(struct transport *transport,
-                           int nr_heads, const struct ref **to_fetch)
+                           int nr_heads, struct ref **to_fetch)
 {
-       struct child_process *helper = get_helper(transport);
-       FILE *file = xfdopen(helper->out, "r");
+       struct helper_data *data = transport->data;
        int i;
        struct strbuf buf = STRBUF_INIT;
 
+       standard_options(transport);
+
        for (i = 0; i < nr_heads; i++) {
                const struct ref *posn = to_fetch[i];
                if (posn->status & REF_STATUS_UPTODATE)
@@ -82,21 +324,220 @@ static int fetch_with_fetch(struct transport *transport,
 
                strbuf_addf(&buf, "fetch %s %s\n",
                            sha1_to_hex(posn->old_sha1), posn->name);
-               write_in_full(helper->in, buf.buf, buf.len);
+       }
+
+       strbuf_addch(&buf, '\n');
+       sendline(data, &buf);
+
+       while (1) {
+               recvline(data, &buf);
+
+               if (!prefixcmp(buf.buf, "lock ")) {
+                       const char *name = buf.buf + 5;
+                       if (transport->pack_lockfile)
+                               warning("%s also locked %s", data->name, name);
+                       else
+                               transport->pack_lockfile = xstrdup(name);
+               }
+               else if (!buf.len)
+                       break;
+               else
+                       warning("%s unexpectedly said: '%s'", data->name, buf.buf);
+       }
+       strbuf_release(&buf);
+       return 0;
+}
+
+static int get_importer(struct transport *transport, struct child_process *fastimport)
+{
+       struct child_process *helper = get_helper(transport);
+       memset(fastimport, 0, sizeof(*fastimport));
+       fastimport->in = helper->out;
+       fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
+       fastimport->argv[0] = "fast-import";
+       fastimport->argv[1] = "--quiet";
+
+       fastimport->git_cmd = 1;
+       return start_command(fastimport);
+}
+
+static int get_exporter(struct transport *transport,
+                       struct child_process *fastexport,
+                       const char *export_marks,
+                       const char *import_marks,
+                       struct string_list *revlist_args)
+{
+       struct child_process *helper = get_helper(transport);
+       int argc = 0, i;
+       memset(fastexport, 0, sizeof(*fastexport));
+
+       /* we need to duplicate helper->in because we want to use it after
+        * fastexport is done with it. */
+       fastexport->out = dup(helper->in);
+       fastexport->argv = xcalloc(4 + revlist_args->nr, sizeof(*fastexport->argv));
+       fastexport->argv[argc++] = "fast-export";
+       if (export_marks)
+               fastexport->argv[argc++] = export_marks;
+       if (import_marks)
+               fastexport->argv[argc++] = import_marks;
+
+       for (i = 0; i < revlist_args->nr; i++)
+               fastexport->argv[argc++] = revlist_args->items[i].string;
+
+       fastexport->git_cmd = 1;
+       return start_command(fastexport);
+}
+
+static int fetch_with_import(struct transport *transport,
+                            int nr_heads, struct ref **to_fetch)
+{
+       struct child_process fastimport;
+       struct helper_data *data = transport->data;
+       int i;
+       struct ref *posn;
+       struct strbuf buf = STRBUF_INIT;
+
+       get_helper(transport);
+
+       if (get_importer(transport, &fastimport))
+               die("Couldn't run fast-import");
+
+       for (i = 0; i < nr_heads; i++) {
+               posn = to_fetch[i];
+               if (posn->status & REF_STATUS_UPTODATE)
+                       continue;
+
+               strbuf_addf(&buf, "import %s\n", posn->name);
+               sendline(data, &buf);
                strbuf_reset(&buf);
+       }
+       disconnect_helper(transport);
+       finish_command(&fastimport);
+       free(fastimport.argv);
+       fastimport.argv = NULL;
+
+       for (i = 0; i < nr_heads; i++) {
+               char *private;
+               posn = to_fetch[i];
+               if (posn->status & REF_STATUS_UPTODATE)
+                       continue;
+               if (data->refspecs)
+                       private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
+               else
+                       private = strdup(posn->name);
+               read_ref(private, posn->old_sha1);
+               free(private);
+       }
+       strbuf_release(&buf);
+       return 0;
+}
+
+static int process_connect_service(struct transport *transport,
+                                  const char *name, const char *exec)
+{
+       struct helper_data *data = transport->data;
+       struct strbuf cmdbuf = STRBUF_INIT;
+       struct child_process *helper;
+       int r, duped, ret = 0;
+       FILE *input;
+
+       helper = get_helper(transport);
+
+       /*
+        * Yes, dup the pipe another time, as we need unbuffered version
+        * of input pipe as FILE*. fclose() closes the underlying fd and
+        * stream buffering only can be changed before first I/O operation
+        * on it.
+        */
+       duped = dup(helper->out);
+       if (duped < 0)
+               die_errno("Can't dup helper output fd");
+       input = xfdopen(duped, "r");
+       setvbuf(input, NULL, _IONBF, 0);
 
-               if (strbuf_getline(&buf, file, '\n') == EOF)
-                       exit(128); /* child died, message supplied already */
+       /*
+        * Handle --upload-pack and friends. This is fire and forget...
+        * just warn if it fails.
+        */
+       if (strcmp(name, exec)) {
+               r = set_helper_option(transport, "servpath", exec);
+               if (r > 0)
+                       warning("Setting remote service path not supported by protocol.");
+               else if (r < 0)
+                       warning("Invalid remote service path.");
        }
+
+       if (data->connect)
+               strbuf_addf(&cmdbuf, "connect %s\n", name);
+       else
+               goto exit;
+
+       sendline(data, &cmdbuf);
+       recvline_fh(input, &cmdbuf);
+       if (!strcmp(cmdbuf.buf, "")) {
+               data->no_disconnect_req = 1;
+               if (debug)
+                       fprintf(stderr, "Debug: Smart transport connection "
+                               "ready.\n");
+               ret = 1;
+       } else if (!strcmp(cmdbuf.buf, "fallback")) {
+               if (debug)
+                       fprintf(stderr, "Debug: Falling back to dumb "
+                               "transport.\n");
+       } else
+               die("Unknown response to connect: %s",
+                       cmdbuf.buf);
+
+exit:
+       fclose(input);
+       return ret;
+}
+
+static int process_connect(struct transport *transport,
+                                    int for_push)
+{
+       struct helper_data *data = transport->data;
+       const char *name;
+       const char *exec;
+
+       name = for_push ? "git-receive-pack" : "git-upload-pack";
+       if (for_push)
+               exec = data->transport_options.receivepack;
+       else
+               exec = data->transport_options.uploadpack;
+
+       return process_connect_service(transport, name, exec);
+}
+
+static int connect_helper(struct transport *transport, const char *name,
+                  const char *exec, int fd[2])
+{
+       struct helper_data *data = transport->data;
+
+       /* Get_helper so connect is inited. */
+       get_helper(transport);
+       if (!data->connect)
+               die("Operation not supported by protocol.");
+
+       if (!process_connect_service(transport, name, exec))
+               die("Can't connect to subservice %s.", name);
+
+       fd[0] = data->helper->out;
+       fd[1] = data->helper->in;
        return 0;
 }
 
 static int fetch(struct transport *transport,
-                int nr_heads, const struct ref **to_fetch)
+                int nr_heads, struct ref **to_fetch)
 {
        struct helper_data *data = transport->data;
        int i, count;
 
+       if (process_connect(transport, 0)) {
+               do_take_over(transport);
+               return transport->fetch(transport, nr_heads, to_fetch);
+       }
+
        count = 0;
        for (i = 0; i < nr_heads; i++)
                if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
@@ -108,27 +549,268 @@ static int fetch(struct transport *transport,
        if (data->fetch)
                return fetch_with_fetch(transport, nr_heads, to_fetch);
 
+       if (data->import)
+               return fetch_with_import(transport, nr_heads, to_fetch);
+
+       return -1;
+}
+
+static int push_refs_with_push(struct transport *transport,
+               struct ref *remote_refs, int flags)
+{
+       int force_all = flags & TRANSPORT_PUSH_FORCE;
+       int mirror = flags & TRANSPORT_PUSH_MIRROR;
+       struct helper_data *data = transport->data;
+       struct strbuf buf = STRBUF_INIT;
+       struct child_process *helper;
+       struct ref *ref;
+
+       helper = get_helper(transport);
+       if (!data->push)
+               return 1;
+
+       for (ref = remote_refs; ref; ref = ref->next) {
+               if (!ref->peer_ref && !mirror)
+                       continue;
+
+               /* Check for statuses set by set_ref_status_for_push() */
+               switch (ref->status) {
+               case REF_STATUS_REJECT_NONFASTFORWARD:
+               case REF_STATUS_UPTODATE:
+                       continue;
+               default:
+                       ; /* do nothing */
+               }
+
+               if (force_all)
+                       ref->force = 1;
+
+               strbuf_addstr(&buf, "push ");
+               if (!ref->deletion) {
+                       if (ref->force)
+                               strbuf_addch(&buf, '+');
+                       if (ref->peer_ref)
+                               strbuf_addstr(&buf, ref->peer_ref->name);
+                       else
+                               strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
+               }
+               strbuf_addch(&buf, ':');
+               strbuf_addstr(&buf, ref->name);
+               strbuf_addch(&buf, '\n');
+       }
+       if (buf.len == 0)
+               return 0;
+
+       standard_options(transport);
+
+       if (flags & TRANSPORT_PUSH_DRY_RUN) {
+               if (set_helper_option(transport, "dry-run", "true") != 0)
+                       die("helper %s does not support dry-run", data->name);
+       }
+
+       strbuf_addch(&buf, '\n');
+       sendline(data, &buf);
+
+       ref = remote_refs;
+       while (1) {
+               char *refname, *msg;
+               int status;
+
+               recvline(data, &buf);
+               if (!buf.len)
+                       break;
+
+               if (!prefixcmp(buf.buf, "ok ")) {
+                       status = REF_STATUS_OK;
+                       refname = buf.buf + 3;
+               } else if (!prefixcmp(buf.buf, "error ")) {
+                       status = REF_STATUS_REMOTE_REJECT;
+                       refname = buf.buf + 6;
+               } else
+                       die("expected ok/error, helper said '%s'\n", buf.buf);
+
+               msg = strchr(refname, ' ');
+               if (msg) {
+                       struct strbuf msg_buf = STRBUF_INIT;
+                       const char *end;
+
+                       *msg++ = '\0';
+                       if (!unquote_c_style(&msg_buf, msg, &end))
+                               msg = strbuf_detach(&msg_buf, NULL);
+                       else
+                               msg = xstrdup(msg);
+                       strbuf_release(&msg_buf);
+
+                       if (!strcmp(msg, "no match")) {
+                               status = REF_STATUS_NONE;
+                               free(msg);
+                               msg = NULL;
+                       }
+                       else if (!strcmp(msg, "up to date")) {
+                               status = REF_STATUS_UPTODATE;
+                               free(msg);
+                               msg = NULL;
+                       }
+                       else if (!strcmp(msg, "non-fast forward")) {
+                               status = REF_STATUS_REJECT_NONFASTFORWARD;
+                               free(msg);
+                               msg = NULL;
+                       }
+               }
+
+               if (ref)
+                       ref = find_ref_by_name(ref, refname);
+               if (!ref)
+                       ref = find_ref_by_name(remote_refs, refname);
+               if (!ref) {
+                       warning("helper reported unexpected status of %s", refname);
+                       continue;
+               }
+
+               if (ref->status != REF_STATUS_NONE) {
+                       /*
+                        * Earlier, the ref was marked not to be pushed, so ignore the ref
+                        * status reported by the remote helper if the latter is 'no match'.
+                        */
+                       if (status == REF_STATUS_NONE)
+                               continue;
+               }
+
+               ref->status = status;
+               ref->remote_status = msg;
+       }
+       strbuf_release(&buf);
+       return 0;
+}
+
+static int push_refs_with_export(struct transport *transport,
+               struct ref *remote_refs, int flags)
+{
+       struct ref *ref;
+       struct child_process *helper, exporter;
+       struct helper_data *data = transport->data;
+       char *export_marks = NULL, *import_marks = NULL;
+       struct string_list revlist_args = STRING_LIST_INIT_NODUP;
+       struct strbuf buf = STRBUF_INIT;
+
+       helper = get_helper(transport);
+
+       write_constant(helper->in, "export\n");
+
+       recvline(data, &buf);
+       if (debug)
+               fprintf(stderr, "Debug: Got export_marks '%s'\n", buf.buf);
+       if (buf.len) {
+               struct strbuf arg = STRBUF_INIT;
+               strbuf_addstr(&arg, "--export-marks=");
+               strbuf_addbuf(&arg, &buf);
+               export_marks = strbuf_detach(&arg, NULL);
+       }
+
+       recvline(data, &buf);
+       if (debug)
+               fprintf(stderr, "Debug: Got import_marks '%s'\n", buf.buf);
+       if (buf.len) {
+               struct strbuf arg = STRBUF_INIT;
+               strbuf_addstr(&arg, "--import-marks=");
+               strbuf_addbuf(&arg, &buf);
+               import_marks = strbuf_detach(&arg, NULL);
+       }
+
+       strbuf_reset(&buf);
+
+       for (ref = remote_refs; ref; ref = ref->next) {
+               char *private;
+               unsigned char sha1[20];
+
+               if (!data->refspecs)
+                       continue;
+               private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
+               if (private && !get_sha1(private, sha1)) {
+                       strbuf_addf(&buf, "^%s", private);
+                       string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
+               }
+
+               string_list_append(&revlist_args, ref->name);
+
+       }
+
+       if (get_exporter(transport, &exporter,
+                        export_marks, import_marks, &revlist_args))
+               die("Couldn't run fast-export");
+
+       data->no_disconnect_req = 1;
+       finish_command(&exporter);
+       disconnect_helper(transport);
+       return 0;
+}
+
+static int push_refs(struct transport *transport,
+               struct ref *remote_refs, int flags)
+{
+       struct helper_data *data = transport->data;
+
+       if (process_connect(transport, 1)) {
+               do_take_over(transport);
+               return transport->push_refs(transport, remote_refs, flags);
+       }
+
+       if (!remote_refs) {
+               fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
+                       "Perhaps you should specify a branch such as 'master'.\n");
+               return 0;
+       }
+
+       if (data->push)
+               return push_refs_with_push(transport, remote_refs, flags);
+
+       if (data->export)
+               return push_refs_with_export(transport, remote_refs, flags);
+
        return -1;
 }
 
+
+static int has_attribute(const char *attrs, const char *attr) {
+       int len;
+       if (!attrs)
+               return 0;
+
+       len = strlen(attr);
+       for (;;) {
+               const char *space = strchrnul(attrs, ' ');
+               if (len == space - attrs && !strncmp(attrs, attr, len))
+                       return 1;
+               if (!*space)
+                       return 0;
+               attrs = space + 1;
+       }
+}
+
 static struct ref *get_refs_list(struct transport *transport, int for_push)
 {
+       struct helper_data *data = transport->data;
        struct child_process *helper;
        struct ref *ret = NULL;
        struct ref **tail = &ret;
        struct ref *posn;
        struct strbuf buf = STRBUF_INIT;
-       FILE *file;
 
        helper = get_helper(transport);
 
-       write_str_in_full(helper->in, "list\n");
+       if (process_connect(transport, for_push)) {
+               do_take_over(transport);
+               return transport->get_refs_list(transport, for_push);
+       }
+
+       if (data->push && for_push)
+               write_str_in_full(helper->in, "list for-push\n");
+       else
+               write_str_in_full(helper->in, "list\n");
 
-       file = xfdopen(helper->out, "r");
        while (1) {
                char *eov, *eon;
-               if (strbuf_getline(&buf, file, '\n') == EOF)
-                       exit(128); /* child died, message supplied already */
+               recvline(data, &buf);
 
                if (!*buf.buf)
                        break;
@@ -145,8 +827,16 @@ static struct ref *get_refs_list(struct transport *transport, int for_push)
                        (*tail)->symref = xstrdup(buf.buf + 1);
                else if (buf.buf[0] != '?')
                        get_sha1_hex(buf.buf, (*tail)->old_sha1);
+               if (eon) {
+                       if (has_attribute(eon + 1, "unchanged")) {
+                               (*tail)->status |= REF_STATUS_UPTODATE;
+                               read_ref((*tail)->name, (*tail)->old_sha1);
+                       }
+               }
                tail = &((*tail)->next);
        }
+       if (debug)
+               fprintf(stderr, "Debug: Read ref listing.\n");
        strbuf_release(&buf);
 
        for (posn = ret; posn; posn = posn->next)
@@ -160,9 +850,327 @@ int transport_helper_init(struct transport *transport, const char *name)
        struct helper_data *data = xcalloc(sizeof(*data), 1);
        data->name = name;
 
+       if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
+               debug = 1;
+
        transport->data = data;
+       transport->set_option = set_helper_option;
        transport->get_refs_list = get_refs_list;
        transport->fetch = fetch;
-       transport->disconnect = disconnect_helper;
+       transport->push_refs = push_refs;
+       transport->disconnect = release_helper;
+       transport->connect = connect_helper;
+       transport->smart_options = &(data->transport_options);
+       return 0;
+}
+
+/*
+ * Linux pipes can buffer 65536 bytes at once (and most platforms can
+ * buffer less), so attempt reads and writes with up to that size.
+ */
+#define BUFFERSIZE 65536
+/* This should be enough to hold debugging message. */
+#define PBUFFERSIZE 8192
+
+/* Print bidirectional transfer loop debug message. */
+static void transfer_debug(const char *fmt, ...)
+{
+       va_list args;
+       char msgbuf[PBUFFERSIZE];
+       static int debug_enabled = -1;
+
+       if (debug_enabled < 0)
+               debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
+       if (!debug_enabled)
+               return;
+
+       va_start(args, fmt);
+       vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
+       va_end(args);
+       fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
+}
+
+/* Stream state: More data may be coming in this direction. */
+#define SSTATE_TRANSFERING 0
+/*
+ * Stream state: No more data coming in this direction, flushing rest of
+ * data.
+ */
+#define SSTATE_FLUSHING 1
+/* Stream state: Transfer in this direction finished. */
+#define SSTATE_FINISHED 2
+
+#define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
+#define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
+#define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
+
+/* Unidirectional transfer. */
+struct unidirectional_transfer {
+       /* Source */
+       int src;
+       /* Destination */
+       int dest;
+       /* Is source socket? */
+       int src_is_sock;
+       /* Is destination socket? */
+       int dest_is_sock;
+       /* Transfer state (TRANSFERING/FLUSHING/FINISHED) */
+       int state;
+       /* Buffer. */
+       char buf[BUFFERSIZE];
+       /* Buffer used. */
+       size_t bufuse;
+       /* Name of source. */
+       const char *src_name;
+       /* Name of destination. */
+       const char *dest_name;
+};
+
+/* Closes the target (for writing) if transfer has finished. */
+static void udt_close_if_finished(struct unidirectional_transfer *t)
+{
+       if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
+               t->state = SSTATE_FINISHED;
+               if (t->dest_is_sock)
+                       shutdown(t->dest, SHUT_WR);
+               else
+                       close(t->dest);
+               transfer_debug("Closed %s.", t->dest_name);
+       }
+}
+
+/*
+ * Tries to read read data from source into buffer. If buffer is full,
+ * no data is read. Returns 0 on success, -1 on error.
+ */
+static int udt_do_read(struct unidirectional_transfer *t)
+{
+       ssize_t bytes;
+
+       if (t->bufuse == BUFFERSIZE)
+               return 0;       /* No space for more. */
+
+       transfer_debug("%s is readable", t->src_name);
+       bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
+       if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
+               errno != EINTR) {
+               error("read(%s) failed: %s", t->src_name, strerror(errno));
+               return -1;
+       } else if (bytes == 0) {
+               transfer_debug("%s EOF (with %i bytes in buffer)",
+                       t->src_name, t->bufuse);
+               t->state = SSTATE_FLUSHING;
+       } else if (bytes > 0) {
+               t->bufuse += bytes;
+               transfer_debug("Read %i bytes from %s (buffer now at %i)",
+                       (int)bytes, t->src_name, (int)t->bufuse);
+       }
+       return 0;
+}
+
+/* Tries to write data from buffer into destination. If buffer is empty,
+ * no data is written. Returns 0 on success, -1 on error.
+ */
+static int udt_do_write(struct unidirectional_transfer *t)
+{
+       size_t bytes;
+
+       if (t->bufuse == 0)
+               return 0;       /* Nothing to write. */
+
+       transfer_debug("%s is writable", t->dest_name);
+       bytes = write(t->dest, t->buf, t->bufuse);
+       if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
+               errno != EINTR) {
+               error("write(%s) failed: %s", t->dest_name, strerror(errno));
+               return -1;
+       } else if (bytes > 0) {
+               t->bufuse -= bytes;
+               if (t->bufuse)
+                       memmove(t->buf, t->buf + bytes, t->bufuse);
+               transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
+                       (int)bytes, t->dest_name, (int)t->bufuse);
+       }
+       return 0;
+}
+
+
+/* State of bidirectional transfer loop. */
+struct bidirectional_transfer_state {
+       /* Direction from program to git. */
+       struct unidirectional_transfer ptg;
+       /* Direction from git to program. */
+       struct unidirectional_transfer gtp;
+};
+
+static void *udt_copy_task_routine(void *udt)
+{
+       struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
+       while (t->state != SSTATE_FINISHED) {
+               if (STATE_NEEDS_READING(t->state))
+                       if (udt_do_read(t))
+                               return NULL;
+               if (STATE_NEEDS_WRITING(t->state))
+                       if (udt_do_write(t))
+                               return NULL;
+               if (STATE_NEEDS_CLOSING(t->state))
+                       udt_close_if_finished(t);
+       }
+       return udt;     /* Just some non-NULL value. */
+}
+
+#ifndef NO_PTHREADS
+
+/*
+ * Join thread, with apporiate errors on failure. Name is name for the
+ * thread (for error messages). Returns 0 on success, 1 on failure.
+ */
+static int tloop_join(pthread_t thread, const char *name)
+{
+       int err;
+       void *tret;
+       err = pthread_join(thread, &tret);
+       if (!tret) {
+               error("%s thread failed", name);
+               return 1;
+       }
+       if (err) {
+               error("%s thread failed to join: %s", name, strerror(err));
+               return 1;
+       }
+       return 0;
+}
+
+/*
+ * Spawn the transfer tasks and then wait for them. Returns 0 on success,
+ * -1 on failure.
+ */
+static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
+{
+       pthread_t gtp_thread;
+       pthread_t ptg_thread;
+       int err;
+       int ret = 0;
+       err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
+               &s->gtp);
+       if (err)
+               die("Can't start thread for copying data: %s", strerror(err));
+       err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
+               &s->ptg);
+       if (err)
+               die("Can't start thread for copying data: %s", strerror(err));
+
+       ret |= tloop_join(gtp_thread, "Git to program copy");
+       ret |= tloop_join(ptg_thread, "Program to git copy");
+       return ret;
+}
+#else
+
+/* Close the source and target (for writing) for transfer. */
+static void udt_kill_transfer(struct unidirectional_transfer *t)
+{
+       t->state = SSTATE_FINISHED;
+       /*
+        * Socket read end left open isn't a disaster if nobody
+        * attempts to read from it (mingw compat headers do not
+        * have SHUT_RD)...
+        *
+        * We can't fully close the socket since otherwise gtp
+        * task would first close the socket it sends data to
+        * while closing the ptg file descriptors.
+        */
+       if (!t->src_is_sock)
+               close(t->src);
+       if (t->dest_is_sock)
+               shutdown(t->dest, SHUT_WR);
+       else
+               close(t->dest);
+}
+
+/*
+ * Join process, with apporiate errors on failure. Name is name for the
+ * process (for error messages). Returns 0 on success, 1 on failure.
+ */
+static int tloop_join(pid_t pid, const char *name)
+{
+       int tret;
+       if (waitpid(pid, &tret, 0) < 0) {
+               error("%s process failed to wait: %s", name, strerror(errno));
+               return 1;
+       }
+       if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
+               error("%s process failed", name);
+               return 1;
+       }
        return 0;
 }
+
+/*
+ * Spawn the transfer tasks and then wait for them. Returns 0 on success,
+ * -1 on failure.
+ */
+static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
+{
+       pid_t pid1, pid2;
+       int ret = 0;
+
+       /* Fork thread #1: git to program. */
+       pid1 = fork();
+       if (pid1 < 0)
+               die_errno("Can't start thread for copying data");
+       else if (pid1 == 0) {
+               udt_kill_transfer(&s->ptg);
+               exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
+       }
+
+       /* Fork thread #2: program to git. */
+       pid2 = fork();
+       if (pid2 < 0)
+               die_errno("Can't start thread for copying data");
+       else if (pid2 == 0) {
+               udt_kill_transfer(&s->gtp);
+               exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
+       }
+
+       /*
+        * Close both streams in parent as to not interfere with
+        * end of file detection and wait for both tasks to finish.
+        */
+       udt_kill_transfer(&s->gtp);
+       udt_kill_transfer(&s->ptg);
+       ret |= tloop_join(pid1, "Git to program copy");
+       ret |= tloop_join(pid2, "Program to git copy");
+       return ret;
+}
+#endif
+
+/*
+ * Copies data from stdin to output and from input to stdout simultaneously.
+ * Additionally filtering through given filter. If filter is NULL, uses
+ * identity filter.
+ */
+int bidirectional_transfer_loop(int input, int output)
+{
+       struct bidirectional_transfer_state state;
+
+       /* Fill the state fields. */
+       state.ptg.src = input;
+       state.ptg.dest = 1;
+       state.ptg.src_is_sock = (input == output);
+       state.ptg.dest_is_sock = 0;
+       state.ptg.state = SSTATE_TRANSFERING;
+       state.ptg.bufuse = 0;
+       state.ptg.src_name = "remote input";
+       state.ptg.dest_name = "stdout";
+
+       state.gtp.src = 0;
+       state.gtp.dest = output;
+       state.gtp.src_is_sock = 0;
+       state.gtp.dest_is_sock = (input == output);
+       state.gtp.state = SSTATE_TRANSFERING;
+       state.gtp.bufuse = 0;
+       state.gtp.src_name = "stdin";
+       state.gtp.dest_name = "remote output";
+
+       return tloop_spawnwait_tasks(&state);
+}