Merge in http-push first stage.

3 files changed, 1911 insertions, 2 deletions

diff --git a/Documentation/git-http-push.txt b/Documentation/git-http-push.txt
new file mode 100644
index 000000000..c7066d66f
--- /dev/null
+++ b/Documentation/git-http-push.txt
@@ -0,0 +1,89 @@
+git-http-push(1)
+================
+
+NAME
+----
+git-http-push - Push missing objects using HTTP/DAV.
+
+
+SYNOPSIS
+--------
+'git-http-push' [--complete] [--force] [--verbose] <url> <ref> [<ref>...]
+
+DESCRIPTION
+-----------
+Sends missing objects to remote repository, and updates the
+remote branch.
+
+
+OPTIONS
+-------
+--complete::
+	Do not assume that the remote repository is complete in its
+	current state, and verify all objects in the entire local
+	ref's history exist in the remote repository.
+
+--force::
+	Usually, the command refuses to update a remote ref that
+	is not an ancestor of the local ref used to overwrite it.
+	This flag disables the check.  What this means is that
+	the remote repository can lose commits; use it with
+	care.
+
+--verbose::
+	Report the list of objects being walked locally and the
+	list of objects successfully sent to the remote repository.
+
+<ref>...:
+	The remote refs to update.
+
+
+Specifying the Refs
+-------------------
+
+A '<ref>' specification can be either a single pattern, or a pair
+of such patterns separated by a colon ":" (this means that a ref name
+cannot have a colon in it).  A single pattern '<name>' is just a 
+shorthand for '<name>:<name>'.
+
+Each pattern pair consists of the source side (before the colon)
+and the destination side (after the colon).  The ref to be
+pushed is determined by finding a match that matches the source
+side, and where it is pushed is determined by using the
+destination side.
+
+ - It is an error if <src> does not match exactly one of the
+   local refs.
+
+ - If <dst> does not match any remote ref, either
+
+   * it has to start with "refs/"; <dst> is used as the
+     destination literally in this case.
+
+   * <src> == <dst> and the ref that matched the <src> must not
+     exist in the set of remote refs; the ref matched <src>
+     locally is used as the name of the destination.
+
+Without '--force', the <src> ref is stored at the remote only if
+<dst> does not exist, or <dst> is a proper subset (i.e. an
+ancestor) of <src>.  This check, known as "fast forward check",
+is performed in order to avoid accidentally overwriting the
+remote ref and lose other peoples' commits from there.
+
+With '--force', the fast forward check is disabled for all refs.
+
+Optionally, a <ref> parameter can be prefixed with a plus '+' sign
+to disable the fast-forward check only on that ref.
+
+
+Author
+------
+Written by Nick Hengeveld <nickh@reactrix.com>
+
+Documentation
+--------------
+Documentation by Nick Hengeveld
+
+GIT
+---
+Part of the gitlink:git[7] suite
diff --git a/Makefile b/Makefile
index 76d33b44f..6f9b0d185 100644
--- a/Makefile
+++ b/Makefile
@@ -6,12 +6,16 @@
 # Define NO_OPENSSL environment variable if you do not have OpenSSL. You will
 # miss out git-rev-list --merge-order. This also implies MOZILLA_SHA1.
 #
-# Define NO_CURL if you do not have curl installed.  git-http-pull is not
-# built, and you cannot use http:// and https:// transports.
+# Define NO_CURL if you do not have curl installed.  git-http-pull and
+# git-http-push are not built, and you cannot use http:// and https://
+# transports.
 #
 # Define CURLDIR=/foo/bar if your curl header and library files are in
 # /foo/bar/include and /foo/bar/lib directories.
 #
+# Define NO_EXPAT if you do not have expat installed.  git-http-push is
+# not built, and you cannot push using http:// and https:// transports.
+#
 # Define NO_STRCASESTR if you don't have strcasestr.
 #
 # Define PPC_SHA1 environment variable when running make to make use of
@@ -219,6 +223,10 @@ ifndef NO_CURL
 		CURL_LIBCURL = -lcurl
 	endif
 	PROGRAMS += git-http-fetch$X
+	ifndef NO_EXPAT
+		EXPAT_LIBEXPAT = -lexpat
+		PROGRAMS += git-http-push$X
+	endif
 endif
 
 ifndef SHELL_PATH
@@ -371,6 +379,7 @@ git-ssh-pull$X: rsh.o fetch.o
 git-ssh-push$X: rsh.o
 
 git-http-fetch$X: LIBS += $(CURL_LIBCURL)
+git-http-push$X: LIBS += $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
 git-rev-list$X: LIBS += $(OPENSSL_LIBSSL)
 
 init-db.o: init-db.c
diff --git a/http-push.c b/http-push.c
new file mode 100644
index 000000000..c10067c17
--- /dev/null
+++ b/http-push.c
@@ -0,0 +1,1811 @@
+#include "cache.h"
+#include "commit.h"
+#include "pack.h"
+#include "fetch.h"
+#include "tag.h"
+#include "blob.h"
+
+#include <curl/curl.h>
+#include <curl/easy.h>
+#include "expat.h"
+
+static const char http_push_usage[] =
+"git-http-push [--complete] [--force] [--verbose] <url> <ref> [<ref>...]\n";
+
+#if LIBCURL_VERSION_NUM >= 0x070908
+#define USE_CURL_MULTI
+#define DEFAULT_MAX_REQUESTS 5
+#endif
+
+#if LIBCURL_VERSION_NUM < 0x070704
+#define curl_global_cleanup() do { /* nothing */ } while(0)
+#endif
+#if LIBCURL_VERSION_NUM < 0x070800
+#define curl_global_init(a) do { /* nothing */ } while(0)
+#endif
+
+#if LIBCURL_VERSION_NUM < 0x070c04
+#define NO_CURL_EASY_DUPHANDLE
+#endif
+
+#define RANGE_HEADER_SIZE 30
+
+/* DAV method names and request body templates */
+#define DAV_LOCK "LOCK"
+#define DAV_MKCOL "MKCOL"
+#define DAV_MOVE "MOVE"
+#define DAV_PROPFIND "PROPFIND"
+#define DAV_PUT "PUT"
+#define DAV_UNLOCK "UNLOCK"
+#define PROPFIND_REQUEST "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:prop xmlns:R=\"%s\">\n<D:supportedlock/>\n</D:prop>\n</D:propfind>"
+#define LOCK_REQUEST "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:lockinfo xmlns:D=\"DAV:\">\n<D:lockscope><D:exclusive/></D:lockscope>\n<D:locktype><D:write/></D:locktype>\n<D:owner>\n<D:href>mailto:%s</D:href>\n</D:owner>\n</D:lockinfo>"
+
+#define LOCK_TIME 600
+#define LOCK_REFRESH 30
+
+static int active_requests = 0;
+static int data_received;
+static int pushing = 0;
+static int aborted = 0;
+
+#ifdef USE_CURL_MULTI
+static int max_requests = -1;
+static CURLM *curlm;
+#endif
+#ifndef NO_CURL_EASY_DUPHANDLE
+static CURL *curl_default;
+#endif
+static struct curl_slist *no_pragma_header;
+static struct curl_slist *default_headers;
+static char curl_errorstr[CURL_ERROR_SIZE];
+
+static int push_verbosely = 0;
+static int push_all = 0;
+static int force_all = 0;
+
+struct buffer
+{
+        size_t posn;
+        size_t size;
+        void *buffer;
+};
+
+struct repo
+{
+	char *url;
+	struct packed_git *packs;
+};
+
+static struct repo *remote = NULL;
+
+enum transfer_state {
+	NEED_CHECK,
+	RUN_HEAD,
+	NEED_PUSH,
+	RUN_MKCOL,
+	RUN_PUT,
+	RUN_MOVE,
+	ABORTED,
+	COMPLETE,
+};
+
+struct transfer_request
+{
+	unsigned char sha1[20];
+	char *url;
+	char *dest;
+	struct active_lock *lock;
+	struct curl_slist *headers;
+	struct buffer buffer;
+	char filename[PATH_MAX];
+	char tmpfile[PATH_MAX];
+	enum transfer_state state;
+	CURLcode curl_result;
+	char errorstr[CURL_ERROR_SIZE];
+	long http_code;
+	unsigned char real_sha1[20];
+	SHA_CTX c;
+	z_stream stream;
+	int zret;
+	int rename;
+	struct active_request_slot *slot;
+	struct transfer_request *next;
+};
+
+struct active_request_slot
+{
+	CURL *curl;
+	FILE *local;
+	int in_use;
+	int done;
+	CURLcode curl_result;
+	long http_code;
+	struct active_request_slot *next;
+};
+
+static struct transfer_request *request_queue_head = NULL;
+static struct active_request_slot *active_queue_head = NULL;
+
+static int curl_ssl_verify = -1;
+static char *ssl_cert = NULL;
+#if LIBCURL_VERSION_NUM >= 0x070902
+static char *ssl_key = NULL;
+#endif
+#if LIBCURL_VERSION_NUM >= 0x070908
+static char *ssl_capath = NULL;
+#endif
+static char *ssl_cainfo = NULL;
+static long curl_low_speed_limit = -1;
+static long curl_low_speed_time = -1;
+
+struct active_lock
+{
+	int ctx_activelock;
+	int ctx_owner;
+	int ctx_owner_href;
+	int ctx_timeout;
+	int ctx_locktoken;
+	int ctx_locktoken_href;
+	char *url;
+	char *owner;
+	char *token;
+	time_t start_time;
+	long timeout;
+	int refreshing;
+};
+
+struct lockprop
+{
+	int supported_lock;
+	int lock_entry;
+	int lock_scope;
+	int lock_type;
+	int lock_exclusive;
+	int lock_exclusive_write;
+};
+
+static int http_options(const char *var, const char *value)
+{
+	if (!strcmp("http.sslverify", var)) {
+		if (curl_ssl_verify == -1) {
+			curl_ssl_verify = git_config_bool(var, value);
+		}
+		return 0;
+	}
+
+	if (!strcmp("http.sslcert", var)) {
+		if (ssl_cert == NULL) {
+			ssl_cert = xmalloc(strlen(value)+1);
+			strcpy(ssl_cert, value);
+		}
+		return 0;
+	}
+#if LIBCURL_VERSION_NUM >= 0x070902
+	if (!strcmp("http.sslkey", var)) {
+		if (ssl_key == NULL) {
+			ssl_key = xmalloc(strlen(value)+1);
+			strcpy(ssl_key, value);
+		}
+		return 0;
+	}
+#endif
+#if LIBCURL_VERSION_NUM >= 0x070908
+	if (!strcmp("http.sslcapath", var)) {
+		if (ssl_capath == NULL) {
+			ssl_capath = xmalloc(strlen(value)+1);
+			strcpy(ssl_capath, value);
+		}
+		return 0;
+	}
+#endif
+	if (!strcmp("http.sslcainfo", var)) {
+		if (ssl_cainfo == NULL) {
+			ssl_cainfo = xmalloc(strlen(value)+1);
+			strcpy(ssl_cainfo, value);
+		}
+		return 0;
+	}
+
+#ifdef USE_CURL_MULTI	
+	if (!strcmp("http.maxrequests", var)) {
+		if (max_requests == -1)
+			max_requests = git_config_int(var, value);
+		return 0;
+	}
+#endif
+
+	if (!strcmp("http.lowspeedlimit", var)) {
+		if (curl_low_speed_limit == -1)
+			curl_low_speed_limit = (long)git_config_int(var, value);
+		return 0;
+	}
+	if (!strcmp("http.lowspeedtime", var)) {
+		if (curl_low_speed_time == -1)
+			curl_low_speed_time = (long)git_config_int(var, value);
+		return 0;
+	}
+
+	/* Fall back on the default ones */
+	return git_default_config(var, value);
+}
+
+static size_t fread_buffer(void *ptr, size_t eltsize, size_t nmemb,
+			   struct buffer *buffer)
+{
+	size_t size = eltsize * nmemb;
+	if (size > buffer->size - buffer->posn)
+		size = buffer->size - buffer->posn;
+	memcpy(ptr, buffer->buffer + buffer->posn, size);
+	buffer->posn += size;
+	return size;
+}
+
+static size_t fwrite_buffer_dynamic(const void *ptr, size_t eltsize,
+				    size_t nmemb, struct buffer *buffer)
+{
+	size_t size = eltsize * nmemb;
+	if (size > buffer->size - buffer->posn) {
+		buffer->size = buffer->size * 3 / 2;
+		if (buffer->size < buffer->posn + size)
+			buffer->size = buffer->posn + size;
+		buffer->buffer = xrealloc(buffer->buffer, buffer->size);
+	}
+	memcpy(buffer->buffer + buffer->posn, ptr, size);
+	buffer->posn += size;
+	data_received++;
+	return size;
+}
+
+static size_t fwrite_null(const void *ptr, size_t eltsize,
+			  size_t nmemb, struct buffer *buffer)
+{
+	data_received++;
+	return eltsize * nmemb;
+}
+
+#ifdef USE_CURL_MULTI
+static void process_curl_messages(void);
+static void process_request_queue(void);
+#endif
+
+static CURL* get_curl_handle(void)
+{
+	CURL* result = curl_easy_init();
+
+	curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
+#if LIBCURL_VERSION_NUM >= 0x070907
+	curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
+#endif
+
+	if (ssl_cert != NULL)
+		curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
+#if LIBCURL_VERSION_NUM >= 0x070902
+	if (ssl_key != NULL)
+		curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
+#endif
+#if LIBCURL_VERSION_NUM >= 0x070908
+	if (ssl_capath != NULL)
+		curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
+#endif
+	if (ssl_cainfo != NULL)
+		curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
+	curl_easy_setopt(result, CURLOPT_FAILONERROR, 1);
+
+	if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
+		curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
+				 curl_low_speed_limit);
+		curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
+				 curl_low_speed_time);
+	}
+
+	return result;
+}
+
+static struct active_request_slot *get_active_slot(void)
+{
+	struct active_request_slot *slot = active_queue_head;
+	struct active_request_slot *newslot;
+
+#ifdef USE_CURL_MULTI
+	int num_transfers;
+
+	/* Wait for a slot to open up if the queue is full */
+	while (active_requests >= max_requests) {
+		curl_multi_perform(curlm, &num_transfers);
+		if (num_transfers < active_requests) {
+			process_curl_messages();
+		}
+	}
+#endif
+
+	while (slot != NULL && slot->in_use) {
+		slot = slot->next;
+	}
+	if (slot == NULL) {
+		newslot = xmalloc(sizeof(*newslot));
+		newslot->curl = NULL;
+		newslot->in_use = 0;
+		newslot->next = NULL;
+
+		slot = active_queue_head;
+		if (slot == NULL) {
+			active_queue_head = newslot;
+		} else {
+			while (slot->next != NULL) {
+				slot = slot->next;
+			}
+			slot->next = newslot;
+		}
+		slot = newslot;
+	}
+
+	if (slot->curl == NULL) {
+#ifdef NO_CURL_EASY_DUPHANDLE
+		slot->curl = get_curl_handle();
+#else
+		slot->curl = curl_easy_duphandle(curl_default);
+#endif
+	}
+
+	active_requests++;
+	slot->in_use = 1;
+	slot->done = 0;
+	slot->local = NULL;
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, default_headers);
+	curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
+
+	return slot;
+}
+
+static int start_active_slot(struct active_request_slot *slot)
+{
+#ifdef USE_CURL_MULTI
+	CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
+
+	if (curlm_result != CURLM_OK &&
+	    curlm_result != CURLM_CALL_MULTI_PERFORM) {
+		active_requests--;
+		slot->in_use = 0;
+		return 0;
+	}
+#endif
+	return 1;
+}
+
+static void run_active_slot(struct active_request_slot *slot)
+{
+#ifdef USE_CURL_MULTI
+	int num_transfers;
+	long last_pos = 0;
+	long current_pos;
+	fd_set readfds;
+	fd_set writefds;
+	fd_set excfds;
+	int max_fd;
+	struct timeval select_timeout;
+	CURLMcode curlm_result;
+
+	while (!slot->done) {
+		data_received = 0;
+		do {
+			curlm_result = curl_multi_perform(curlm,
+							  &num_transfers);
+		} while (curlm_result == CURLM_CALL_MULTI_PERFORM);
+		if (num_transfers < active_requests) {
+			process_curl_messages();
+			process_request_queue();
+		}
+
+		if (!data_received && slot->local != NULL) {
+			current_pos = ftell(slot->local);
+			if (current_pos > last_pos)
+				data_received++;
+			last_pos = current_pos;
+		}
+
+		if (!slot->done && !data_received) {
+			max_fd = 0;
+			FD_ZERO(&readfds);
+			FD_ZERO(&writefds);
+			FD_ZERO(&excfds);
+			select_timeout.tv_sec = 0;
+			select_timeout.tv_usec = 50000;
+			select(max_fd, &readfds, &writefds,
+			       &excfds, &select_timeout);
+		}
+	}
+#else
+	slot->curl_result = curl_easy_perform(slot->curl);
+	active_requests--;
+#endif
+}
+
+static void start_check(struct transfer_request *request)
+{
+	char *hex = sha1_to_hex(request->sha1);
+	struct active_request_slot *slot;
+	char *posn;
+
+	request->url = xmalloc(strlen(remote->url) + 55);
+	strcpy(request->url, remote->url);
+	posn = request->url + strlen(remote->url);
+	strcpy(posn, "objects/");
+	posn += 8;
+	memcpy(posn, hex, 2);
+	posn += 2;
+	*(posn++) = '/';
+	strcpy(posn, hex + 2);
+
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, request->errorstr);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, request->url);
+	curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
+
+	if (start_active_slot(slot)) {
+		request->slot = slot;
+		request->state = RUN_HEAD;
+	} else {
+		request->state = ABORTED;
+		free(request->url);
+	}
+}
+
+static void start_mkcol(struct transfer_request *request)
+{
+	char *hex = sha1_to_hex(request->sha1);
+	struct active_request_slot *slot;
+	char *posn;
+
+	request->url = xmalloc(strlen(remote->url) + 13);
+	strcpy(request->url, remote->url);
+	posn = request->url + strlen(remote->url);
+	strcpy(posn, "objects/");
+	posn += 8;
+	memcpy(posn, hex, 2);
+	posn += 2;
+	strcpy(posn, "/");
+
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1); /* undo PUT setup */
+	curl_easy_setopt(slot->curl, CURLOPT_URL, request->url);
+	curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, request->errorstr);
+	curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, DAV_MKCOL);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_null);
+
+	if (start_active_slot(slot)) {
+		request->slot = slot;
+		request->state = RUN_MKCOL;
+	} else {
+		request->state = ABORTED;
+		free(request->url);
+	}
+}
+
+static void start_put(struct transfer_request *request)
+{
+	char *hex = sha1_to_hex(request->sha1);
+	struct active_request_slot *slot;
+	char *posn;
+	char type[20];
+	char hdr[50];
+	void *unpacked;
+	unsigned long len;
+	int hdrlen;
+	ssize_t size;
+	z_stream stream;
+
+	unpacked = read_sha1_file(request->sha1, type, &len);
+	hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
+
+	/* Set it up */
+	memset(&stream, 0, sizeof(stream));
+	deflateInit(&stream, Z_BEST_COMPRESSION);
+	size = deflateBound(&stream, len + hdrlen);
+	request->buffer.buffer = xmalloc(size);
+
+	/* Compress it */
+	stream.next_out = request->buffer.buffer;
+	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);
+
+	request->buffer.size = stream.total_out;
+	request->buffer.posn = 0;
+
+	if (request->url != NULL)
+		free(request->url);
+	request->url = xmalloc(strlen(remote->url) + 
+			       strlen(request->lock->token) + 51);
+	strcpy(request->url, remote->url);
+	posn = request->url + strlen(remote->url);
+	strcpy(posn, "objects/");
+	posn += 8;
+	memcpy(posn, hex, 2);
+	posn += 2;
+	*(posn++) = '/';
+	strcpy(posn, hex + 2);
+	request->dest = xmalloc(strlen(request->url) + 14);
+	sprintf(request->dest, "Destination: %s", request->url);
+	posn += 38;
+	*(posn++) = '.';
+	strcpy(posn, request->lock->token);
+
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_INFILE, &request->buffer);
+	curl_easy_setopt(slot->curl, CURLOPT_INFILESIZE, request->buffer.size);
+	curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, fread_buffer);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_null);
+	curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, DAV_PUT);
+	curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 1);
+	curl_easy_setopt(slot->curl, CURLOPT_PUT, 1);
+	curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, request->url);
+
+	if (start_active_slot(slot)) {
+		request->slot = slot;
+		request->state = RUN_PUT;
+	} else {
+		request->state = ABORTED;
+		free(request->url);
+	}
+}
+
+static void start_move(struct transfer_request *request)
+{
+	struct active_request_slot *slot;
+	struct curl_slist *dav_headers = NULL;
+
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1); /* undo PUT setup */
+	curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, DAV_MOVE);
+	dav_headers = curl_slist_append(dav_headers, request->dest);
+	dav_headers = curl_slist_append(dav_headers, "Overwrite: T");
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_null);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, request->url);
+
+	if (start_active_slot(slot)) {
+		request->slot = slot;
+		request->state = RUN_MOVE;
+	} else {
+		request->state = ABORTED;
+		free(request->url);
+	}
+}
+
+int refresh_lock(struct active_lock *lock)
+{
+	struct active_request_slot *slot;
+	char *if_header;
+	char timeout_header[25];
+	struct curl_slist *dav_headers = NULL;
+	int rc = 0;
+
+	lock->refreshing = 1;
+
+	if_header = xmalloc(strlen(lock->token) + 25);
+	sprintf(if_header, "If: (<opaquelocktoken:%s>)", lock->token);
+	sprintf(timeout_header, "Timeout: Second-%ld", lock->timeout);
+	dav_headers = curl_slist_append(dav_headers, if_header);
+	dav_headers = curl_slist_append(dav_headers, timeout_header);
+
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_null);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, lock->url);
+	curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, DAV_LOCK);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
+
+	if (start_active_slot(slot)) {
+		run_active_slot(slot);
+		if (slot->curl_result != CURLE_OK) {
+			fprintf(stderr, "Got HTTP error %ld\n", slot->http_code);
+		} else {
+			lock->start_time = time(NULL);
+			rc = 1;
+		}
+	}
+
+	lock->refreshing = 0;
+	curl_slist_free_all(dav_headers);
+	free(if_header);
+
+	return rc;
+}
+
+static void finish_request(struct transfer_request *request)
+{
+	time_t current_time = time(NULL);
+	int time_remaining;
+
+	request->curl_result =	request->slot->curl_result;
+	request->http_code = request->slot->http_code;
+	request->slot = NULL;
+
+	/* Refresh the lock if it is close to timing out */
+	time_remaining = request->lock->start_time + request->lock->timeout
+		- current_time;
+	if (time_remaining < LOCK_REFRESH && !request->lock->refreshing) {
+		if (!refresh_lock(request->lock)) {
+			fprintf(stderr, "Unable to refresh remote lock\n");
+			aborted = 1;
+		}
+	}
+
+	if (request->headers != NULL)
+		curl_slist_free_all(request->headers);
+	if (request->state == RUN_HEAD) {
+		if (request->http_code == 404) {
+			request->state = NEED_PUSH;
+		} else if (request->curl_result == CURLE_OK) {
+			request->state = COMPLETE;
+		} else {
+			fprintf(stderr, "HEAD %s failed, aborting (%d/%ld)\n",
+				sha1_to_hex(request->sha1),
+				request->curl_result, request->http_code);
+			request->state = ABORTED;
+			aborted = 1;
+		}
+	} else if (request->state == RUN_MKCOL) {
+		if (request->curl_result == CURLE_OK ||
+		    request->http_code == 405) {
+			start_put(request);
+		} else {
+			fprintf(stderr, "MKCOL %s failed, aborting (%d/%ld)\n",
+				sha1_to_hex(request->sha1),
+				request->curl_result, request->http_code);
+			request->state = ABORTED;
+			aborted = 1;
+		}
+	} else if (request->state == RUN_PUT) {
+		if (request->curl_result == CURLE_OK) {
+			start_move(request);
+		} else {
+			fprintf(stderr,	"PUT %s failed, aborting (%d/%ld)\n",
+				sha1_to_hex(request->sha1),
+				request->curl_result, request->http_code);
+			request->state = ABORTED;
+			aborted = 1;
+		}
+	} else if (request->state == RUN_MOVE) {
+		if (request->curl_result == CURLE_OK) {
+			if (push_verbosely)
+				fprintf(stderr,
+					"sent %s\n",
+					sha1_to_hex(request->sha1));
+			request->state = COMPLETE;
+		} else {
+			fprintf(stderr, "MOVE %s failed, aborting (%d/%ld)\n",
+				sha1_to_hex(request->sha1),
+				request->curl_result, request->http_code);
+			request->state = ABORTED;
+			aborted = 1;
+		}
+	}
+}
+
+static void release_request(struct transfer_request *request)
+{
+	struct transfer_request *entry = request_queue_head;
+
+	if (request == request_queue_head) {
+		request_queue_head = request->next;
+	} else {
+		while (entry->next != NULL && entry->next != request)
+			entry = entry->next;
+		if (entry->next == request)
+			entry->next = entry->next->next;
+	}
+
+	free(request->url);
+	free(request);
+}
+
+#ifdef USE_CURL_MULTI
+void process_curl_messages(void)
+{
+	int num_messages;
+	struct active_request_slot *slot;
+	struct transfer_request *request = NULL;
+	CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
+
+	while (curl_message != NULL) {
+		if (curl_message->msg == CURLMSG_DONE) {
+			slot = active_queue_head;
+			while (slot != NULL &&
+			       slot->curl != curl_message->easy_handle)
+				slot = slot->next;
+			if (slot != NULL) {
+				curl_multi_remove_handle(curlm, slot->curl);
+				active_requests--;
+				slot->done = 1;
+				slot->in_use = 0;
+				slot->curl_result = curl_message->data.result;
+				curl_easy_getinfo(slot->curl,
+						  CURLINFO_HTTP_CODE,
+						  &slot->http_code);
+				request = request_queue_head;
+				while (request != NULL &&
+				       request->slot != slot)
+					request = request->next;
+				if (request != NULL)
+					finish_request(request);
+			} else {
+				fprintf(stderr, "Received DONE message for unknown request!\n");
+			}
+		} else {
+			fprintf(stderr, "Unknown CURL message received: %d\n",
+				(int)curl_message->msg);
+		}
+		curl_message = curl_multi_info_read(curlm, &num_messages);
+	}
+}
+
+void process_request_queue(void)
+{
+	struct transfer_request *request = request_queue_head;
+	struct active_request_slot *slot = active_queue_head;
+	int num_transfers;
+
+	if (aborted)
+		return;
+
+	while (active_requests < max_requests && request != NULL) {
+		if (!pushing && request->state == NEED_CHECK) {
+			start_check(request);
+			curl_multi_perform(curlm, &num_transfers);
+		} else if (pushing && request->state == NEED_PUSH) {
+			start_mkcol(request);
+			curl_multi_perform(curlm, &num_transfers);
+		}
+		request = request->next;
+	}
+
+	while (slot != NULL) {
+		if (!slot->in_use && slot->curl != NULL) {
+			curl_easy_cleanup(slot->curl);
+			slot->curl = NULL;
+		}
+		slot = slot->next;
+	}				
+}
+#endif
+
+void process_waiting_requests(void)
+{
+	struct active_request_slot *slot = active_queue_head;
+
+	while (slot != NULL)
+		if (slot->in_use) {
+			run_active_slot(slot);
+			slot = active_queue_head;
+		} else {
+			slot = slot->next;
+		}
+}
+
+void add_request(unsigned char *sha1, struct active_lock *lock)
+{
+	struct transfer_request *request = request_queue_head;
+	struct packed_git *target;
+	
+	while (request != NULL && memcmp(request->sha1, sha1, 20))
+		request = request->next;
+	if (request != NULL)
+		return;
+
+	target = find_sha1_pack(sha1, remote->packs);
+	if (target)
+		return;
+
+	request = xmalloc(sizeof(*request));
+	memcpy(request->sha1, sha1, 20);
+	request->url = NULL;
+	request->lock = lock;
+	request->headers = NULL;
+	request->state = NEED_CHECK;
+	request->next = request_queue_head;
+	request_queue_head = request;
+#ifdef USE_CURL_MULTI
+	process_request_queue();
+	process_curl_messages();
+#endif
+}
+
+static int fetch_index(unsigned char *sha1)
+{
+	char *hex = sha1_to_hex(sha1);
+	char *filename;
+	char *url;
+	char tmpfile[PATH_MAX];
+	long prev_posn = 0;
+	char range[RANGE_HEADER_SIZE];
+	struct curl_slist *range_header = NULL;
+
+	FILE *indexfile;
+	struct active_request_slot *slot;
+
+	/* Don't use the index if the pack isn't there */
+	url = xmalloc(strlen(remote->url) + 65);
+	sprintf(url, "%s/objects/pack/pack-%s.pack", remote->url, hex);
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+	curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
+	if (start_active_slot(slot)) {
+		run_active_slot(slot);
+		if (slot->curl_result != CURLE_OK) {
+			free(url);
+			return error("Unable to verify pack %s is available",
+				     hex);
+		}
+	} else {
+		return error("Unable to start request");
+	}
+
+	if (has_pack_index(sha1))
+		return 0;
+
+	if (push_verbosely)
+		fprintf(stderr, "Getting index for pack %s\n", hex);
+	
+	sprintf(url, "%s/objects/pack/pack-%s.idx", remote->url, hex);
+	
+	filename = sha1_pack_index_name(sha1);
+	snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
+	indexfile = fopen(tmpfile, "a");
+	if (!indexfile)
+		return error("Unable to open local file %s for pack index",
+			     filename);
+
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
+	curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
+	slot->local = indexfile;
+
+	/* If there is data present from a previous transfer attempt,
+	   resume where it left off */
+	prev_posn = ftell(indexfile);
+	if (prev_posn>0) {
+		if (push_verbosely)
+			fprintf(stderr,
+				"Resuming fetch of index for pack %s at byte %ld\n",
+				hex, prev_posn);
+		sprintf(range, "Range: bytes=%ld-", prev_posn);
+		range_header = curl_slist_append(range_header, range);
+		curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
+	}
+
+	if (start_active_slot(slot)) {
+		run_active_slot(slot);
+		if (slot->curl_result != CURLE_OK) {
+			free(url);
+			fclose(indexfile);
+			return error("Unable to get pack index %s\n%s", url,
+				     curl_errorstr);
+		}
+	} else {
+		free(url);
+		return error("Unable to start request");
+	}
+
+	free(url);
+	fclose(indexfile);
+
+	return move_temp_to_file(tmpfile, filename);
+}
+
+static int setup_index(unsigned char *sha1)
+{
+	struct packed_git *new_pack;
+
+	if (fetch_index(sha1))
+		return -1;
+
+	new_pack = parse_pack_index(sha1);
+	new_pack->next = remote->packs;
+	remote->packs = new_pack;
+	return 0;
+}
+
+static int fetch_indices()
+{
+	unsigned char sha1[20];
+	char *url;
+	struct buffer buffer;
+	char *data;
+	int i = 0;
+
+	struct active_request_slot *slot;
+
+	data = xmalloc(4096);
+	memset(data, 0, 4096);
+	buffer.size = 4096;
+	buffer.posn = 0;
+	buffer.buffer = data;
+
+	if (push_verbosely)
+		fprintf(stderr, "Getting pack list\n");
+	
+	url = xmalloc(strlen(remote->url) + 21);
+	sprintf(url, "%s/objects/info/packs", remote->url);
+
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+			 fwrite_buffer_dynamic);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
+	if (start_active_slot(slot)) {
+		run_active_slot(slot);
+		if (slot->curl_result != CURLE_OK) {
+			free(buffer.buffer);
+			free(url);
+			if (slot->http_code == 404)
+				return 0;
+			else
+				return error("%s", curl_errorstr);
+		}
+	} else {
+		free(buffer.buffer);
+		free(url);
+		return error("Unable to start request");
+	}
+	free(url);
+
+	data = buffer.buffer;
+	while (i < buffer.posn) {
+		switch (data[i]) {
+		case 'P':
+			i++;
+			if (i + 52 < buffer.posn &&
+			    !strncmp(data + i, " pack-", 6) &&
+			    !strncmp(data + i + 46, ".pack\n", 6)) {
+				get_sha1_hex(data + i + 6, sha1);
+				setup_index(sha1);
+				i += 51;
+				break;
+			}
+		default:
+			while (data[i] != '\n')
+				i++;
+		}
+		i++;
+	}
+
+	free(buffer.buffer);
+	return 0;
+}
+
+static inline int needs_quote(int ch)
+{
+	switch (ch) {
+	case '/': case '-': case '.':
+	case 'A'...'Z':	case 'a'...'z':	case '0'...'9':
+		return 0;
+	default:
+		return 1;
+	}
+}
+
+static inline int hex(int v)
+{
+	if (v < 10) return '0' + v;
+	else return 'A' + v - 10;
+}
+
+static char *quote_ref_url(const char *base, const char *ref)
+{
+	const char *cp;
+	char *dp, *qref;
+	int len, baselen, ch;
+
+	baselen = strlen(base);
+	len = baselen + 12; /* "refs/heads/" + NUL */
+	for (cp = ref; (ch = *cp) != 0; cp++, len++)
+		if (needs_quote(ch))
+			len += 2; /* extra two hex plus replacement % */
+	qref = xmalloc(len);
+	memcpy(qref, base, baselen);
+	memcpy(qref + baselen, "refs/heads/", 11);
+	for (cp = ref, dp = qref + baselen + 11; (ch = *cp) != 0; cp++) {
+		if (needs_quote(ch)) {
+			*dp++ = '%';
+			*dp++ = hex((ch >> 4) & 0xF);
+			*dp++ = hex(ch & 0xF);
+		}
+		else
+			*dp++ = ch;
+	}
+	*dp = 0;
+
+	return qref;
+}
+
+int fetch_ref(char *ref, unsigned char *sha1)
+{
+        char *url;
+        char hex[42];
+        struct buffer buffer;
+	char *base = remote->url;
+	struct active_request_slot *slot;
+        buffer.size = 41;
+        buffer.posn = 0;
+        buffer.buffer = hex;
+        hex[41] = '\0';
+        
+	url = quote_ref_url(base, ref);
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+			 fwrite_buffer_dynamic);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+	if (start_active_slot(slot)) {
+		run_active_slot(slot);
+		if (slot->curl_result != CURLE_OK)
+			return error("Couldn't get %s for %s\n%s",
+				     url, ref, curl_errorstr);
+	} else {
+		return error("Unable to start request");
+	}
+
+        hex[40] = '\0';
+        get_sha1_hex(hex, sha1);
+        return 0;
+}
+
+static void
+start_activelock_element(void *userData, const char *name, const char **atts)
+{
+	struct active_lock *lock = (struct active_lock *)userData;
+
+	if (lock->ctx_activelock && !strcmp(name, "D:timeout"))
+		lock->ctx_timeout = 1;
+	else if (lock->ctx_owner && strstr(name, "href"))
+		lock->ctx_owner_href = 1;
+	else if (lock->ctx_activelock && strstr(name, "owner"))
+		lock->ctx_owner = 1;
+	else if (lock->ctx_locktoken && !strcmp(name, "D:href"))
+		lock->ctx_locktoken_href = 1;
+	else if (lock->ctx_activelock && !strcmp(name, "D:locktoken"))
+		lock->ctx_locktoken = 1;
+	else if (!strcmp(name, "D:activelock"))
+		lock->ctx_activelock = 1;
+}
+
+static void
+end_activelock_element(void *userData, const char *name)
+{
+	struct active_lock *lock = (struct active_lock *)userData;
+
+	if (lock->ctx_timeout && !strcmp(name, "D:timeout")) {
+		lock->ctx_timeout = 0;
+	} else if (lock->ctx_owner_href && strstr(name, "href")) {
+		lock->ctx_owner_href = 0;
+	} else if (lock->ctx_owner && strstr(name, "owner")) {
+		lock->ctx_owner = 0;
+	} else if (lock->ctx_locktoken_href && !strcmp(name, "D:href")) {
+		lock->ctx_locktoken_href = 0;
+	} else if (lock->ctx_locktoken && !strcmp(name, "D:locktoken")) {
+		lock->ctx_locktoken = 0;
+	} else if (lock->ctx_activelock && !strcmp(name, "D:activelock")) {
+		lock->ctx_activelock = 0;
+	}
+}
+
+static void
+activelock_cdata(void *userData, const XML_Char *s, int len)
+{
+	struct active_lock *lock = (struct active_lock *)userData;
+	char *this = malloc(len+1);
+	strncpy(this, s, len);
+
+	if (lock->ctx_owner_href) {
+		lock->owner = malloc(len+1);
+		strcpy(lock->owner, this);
+	} else if (lock->ctx_locktoken_href) {
+		if (!strncmp(this, "opaquelocktoken:", 16)) {
+			lock->token = malloc(len-15);
+			strcpy(lock->token, this+16);
+		}
+	} else if (lock->ctx_timeout) {
+		if (!strncmp(this, "Second-", 7))
+			lock->timeout = strtol(this+7, NULL, 10);
+	}
+
+	free(this);
+}
+
+static void
+start_lockprop_element(void *userData, const char *name, const char **atts)
+{
+	struct lockprop *prop = (struct lockprop *)userData;
+
+	if (prop->lock_type && !strcmp(name, "D:write")) {
+		if (prop->lock_exclusive) {
+			prop->lock_exclusive_write = 1;
+		}
+	} else if (prop->lock_scope && !strcmp(name, "D:exclusive")) {
+		prop->lock_exclusive = 1;
+	} else if (prop->lock_entry) {
+		if (!strcmp(name, "D:lockscope")) {
+			prop->lock_scope = 1;
+		} else if (!strcmp(name, "D:locktype")) {
+			prop->lock_type = 1;
+		}
+	} else if (prop->supported_lock) {
+		if (!strcmp(name, "D:lockentry")) {
+			prop->lock_entry = 1;
+		}
+	} else if (!strcmp(name, "D:supportedlock")) {
+		prop->supported_lock = 1;
+	}
+}
+
+static void
+end_lockprop_element(void *userData, const char *name)
+{
+	struct lockprop *prop = (struct lockprop *)userData;
+
+	if (!strcmp(name, "D:lockentry")) {
+		prop->lock_entry = 0;
+		prop->lock_scope = 0;
+		prop->lock_type = 0;
+		prop->lock_exclusive = 0;
+	} else if (!strcmp(name, "D:supportedlock")) {
+		prop->supported_lock = 0;
+	}
+}
+
+struct active_lock *lock_remote(char *file, long timeout)
+{
+	struct active_request_slot *slot;
+	struct buffer out_buffer;
+	struct buffer in_buffer;
+	char *out_data;
+	char *in_data;
+	char *url;
+	char *ep;
+	char timeout_header[25];
+	struct active_lock *new_lock;
+	XML_Parser parser = XML_ParserCreate(NULL);
+	enum XML_Status result;
+	struct curl_slist *dav_headers = NULL;
+
+	url = xmalloc(strlen(remote->url) + strlen(file) + 1);
+	sprintf(url, "%s%s", remote->url, file);
+
+	/* Make sure leading directories exist for the remote ref */
+	ep = strchr(url + strlen(remote->url) + 11, '/');
+	while (ep) {
+		*ep = 0;
+		slot = get_active_slot();
+		curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
+		curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+		curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, DAV_MKCOL);
+		curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_null);
+		if (start_active_slot(slot)) {
+			run_active_slot(slot);
+			if (slot->curl_result != CURLE_OK &&
+			    slot->http_code != 405) {
+				fprintf(stderr,
+					"Unable to create branch path %s\n",
+					url);
+				free(url);
+				return NULL;
+			}
+		} else {
+			fprintf(stderr, "Unable to start request\n");
+			free(url);
+			return NULL;
+		}
+		*ep = '/';
+		ep = strchr(ep + 1, '/');
+	}
+
+	out_buffer.size = strlen(LOCK_REQUEST) + strlen(git_default_email) - 2;
+	out_data = xmalloc(out_buffer.size + 1);
+	snprintf(out_data, out_buffer.size + 1, LOCK_REQUEST, git_default_email);
+	out_buffer.posn = 0;
+	out_buffer.buffer = out_data;
+
+	in_buffer.size = 4096;
+	in_data = xmalloc(in_buffer.size);
+	in_buffer.posn = 0;
+	in_buffer.buffer = in_data;
+
+	new_lock = xmalloc(sizeof(*new_lock));
+	new_lock->owner = NULL;
+	new_lock->token = NULL;
+	new_lock->timeout = -1;
+	new_lock->refreshing = 0;
+
+	sprintf(timeout_header, "Timeout: Second-%ld", timeout);
+	dav_headers = curl_slist_append(dav_headers, timeout_header);
+	dav_headers = curl_slist_append(dav_headers, "Content-Type: text/xml");
+
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_INFILE, &out_buffer);
+	curl_easy_setopt(slot->curl, CURLOPT_INFILESIZE, out_buffer.size);
+	curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, fread_buffer);
+	curl_easy_setopt(slot->curl, CURLOPT_FILE, &in_buffer);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+			 fwrite_buffer_dynamic);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+	curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 1);
+	curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, DAV_LOCK);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
+
+	if (start_active_slot(slot)) {
+		run_active_slot(slot);
+		if (slot->curl_result != CURLE_OK) {
+			fprintf(stderr, "Got HTTP error %ld\n", slot->http_code);
+			free(new_lock);
+			free(url);
+			free(out_data);
+			free(in_data);
+			return NULL;
+		}
+	} else {
+		free(new_lock);
+		free(url);
+		free(out_data);
+		free(in_data);
+		fprintf(stderr, "Unable to start request\n");
+		return NULL;
+	}
+
+	free(out_data);
+
+	XML_SetUserData(parser, new_lock);
+	XML_SetElementHandler(parser, start_activelock_element,
+				      end_activelock_element);
+	XML_SetCharacterDataHandler(parser, activelock_cdata);
+	result = XML_Parse(parser, in_buffer.buffer, in_buffer.posn, 1);
+	free(in_data);
+	if (result != XML_STATUS_OK) {
+		fprintf(stderr, "%s", XML_ErrorString(
+				XML_GetErrorCode(parser)));
+		free(url);
+		free(new_lock);
+		return NULL;
+	}
+
+	if (new_lock->token == NULL || new_lock->timeout <= 0) {
+		if (new_lock->token != NULL)
+			free(new_lock->token);
+		if (new_lock->owner != NULL)
+			free(new_lock->owner);
+		free(url);
+		free(new_lock);
+		return NULL;
+	}
+
+	new_lock->url = url;
+	new_lock->start_time = time(NULL);
+	return new_lock;
+}
+
+int unlock_remote(struct active_lock *lock)
+{
+	struct active_request_slot *slot;
+	char *lock_token_header;
+	struct curl_slist *dav_headers = NULL;
+	int rc = 0;
+
+	lock_token_header = xmalloc(strlen(lock->token) + 31);
+	sprintf(lock_token_header, "Lock-Token: <opaquelocktoken:%s>",
+		lock->token);
+	dav_headers = curl_slist_append(dav_headers, lock_token_header);
+
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_null);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, lock->url);
+	curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, DAV_UNLOCK);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
+
+	if (start_active_slot(slot)) {
+		run_active_slot(slot);
+		if (slot->curl_result == CURLE_OK)
+			rc = 1;
+		else
+			fprintf(stderr, "Got HTTP error %ld\n",
+				slot->http_code);
+	} else {
+		fprintf(stderr, "Unable to start request\n");
+	}
+
+	curl_slist_free_all(dav_headers);
+	free(lock_token_header);
+
+	if (lock->owner != NULL)
+		free(lock->owner);
+	free(lock->url);
+	free(lock->token);
+	free(lock);
+
+	return rc;
+}
+
+int check_locking()
+{
+	struct active_request_slot *slot;
+	struct buffer in_buffer;
+	struct buffer out_buffer;
+	char *in_data;
+	char *out_data;
+	XML_Parser parser = XML_ParserCreate(NULL);
+	enum XML_Status result;
+	struct lockprop supported_lock;
+	struct curl_slist *dav_headers = NULL;
+
+	out_buffer.size = strlen(PROPFIND_REQUEST) + strlen(remote->url) - 2;
+	out_data = xmalloc(out_buffer.size + 1);
+	snprintf(out_data, out_buffer.size + 1, PROPFIND_REQUEST, remote->url);
+	out_buffer.posn = 0;
+	out_buffer.buffer = out_data;
+
+	in_buffer.size = 4096;
+	in_data = xmalloc(in_buffer.size);
+	in_buffer.posn = 0;
+	in_buffer.buffer = in_data;
+
+	dav_headers = curl_slist_append(dav_headers, "Depth: 0");
+	dav_headers = curl_slist_append(dav_headers, "Content-Type: text/xml");
+	
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_INFILE, &out_buffer);
+	curl_easy_setopt(slot->curl, CURLOPT_INFILESIZE, out_buffer.size);
+	curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, fread_buffer);
+	curl_easy_setopt(slot->curl, CURLOPT_FILE, &in_buffer);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+			 fwrite_buffer_dynamic);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, remote->url);
+	curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 1);
+	curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, DAV_PROPFIND);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
+
+	if (start_active_slot(slot)) {
+		run_active_slot(slot);
+		free(out_data);
+		if (slot->curl_result != CURLE_OK) {
+			free(in_buffer.buffer);
+			return -1;
+		}
+
+		XML_SetUserData(parser, &supported_lock);
+		XML_SetElementHandler(parser, start_lockprop_element,
+				      end_lockprop_element);
+		result = XML_Parse(parser, in_buffer.buffer, in_buffer.posn, 1);
+		free(in_buffer.buffer);
+		if (result != XML_STATUS_OK)
+			return error("%s", XML_ErrorString(
+					     XML_GetErrorCode(parser)));
+	} else {
+		free(out_data);
+		free(in_buffer.buffer);
+		return error("Unable to start request");
+	}
+
+	if (supported_lock.lock_exclusive_write)
+		return 0;
+	else
+		return 1;
+}
+
+int is_ancestor(unsigned char *sha1, struct commit *commit)
+{
+	struct commit_list *parents;
+
+	if (parse_commit(commit))
+		return 0;
+	parents = commit->parents;
+	for (; parents; parents = parents->next) {
+		if (!memcmp(sha1, parents->item->object.sha1, 20)) {
+			return 1;
+		} else if (parents->item->object.type == commit_type) {
+			if (is_ancestor(
+				    sha1,
+				    (struct commit *)&parents->item->object
+				    ))
+				return 1;
+		}
+	}
+	return 0;
+}
+
+void get_delta(unsigned char *sha1, struct object *obj,
+	       struct active_lock *lock)
+{
+	struct commit *commit;
+	struct commit_list *parents;
+	struct tree *tree;
+	struct tree_entry_list *entry;
+
+	if (sha1 && !memcmp(sha1, obj->sha1, 20))
+		return;
+
+	if (aborted)
+		return;
+
+	if (obj->type == commit_type) {
+		if (push_verbosely)
+			fprintf(stderr, "walk %s\n", sha1_to_hex(obj->sha1));
+		add_request(obj->sha1, lock);
+		commit = (struct commit *)obj;
+		if (parse_commit(commit)) {
+			fprintf(stderr, "Error parsing commit %s\n",
+				sha1_to_hex(obj->sha1));
+			aborted = 1;
+			return;
+		}
+		parents = commit->parents;
+		for (; parents; parents = parents->next)
+			if (sha1 == NULL ||
+			    memcmp(sha1, parents->item->object.sha1, 20))
+				get_delta(sha1, &parents->item->object,
+					  lock);
+		get_delta(sha1, &commit->tree->object, lock);
+	} else if (obj->type == tree_type) {
+		if (push_verbosely)
+			fprintf(stderr, "walk %s\n", sha1_to_hex(obj->sha1));
+		add_request(obj->sha1, lock);
+		tree = (struct tree *)obj;
+		if (parse_tree(tree)) {
+			fprintf(stderr, "Error parsing tree %s\n",
+				sha1_to_hex(obj->sha1));
+			aborted = 1;
+			return;
+		}
+		entry = tree->entries;
+		tree->entries = NULL;
+		while (entry) {
+			struct tree_entry_list *next = entry->next;
+			get_delta(sha1, entry->item.any, lock);
+			free(entry->name);
+			free(entry);
+			entry = next;
+		}
+	} else if (obj->type == blob_type || obj->type == tag_type) {
+		add_request(obj->sha1, lock);
+	}
+}
+
+int update_remote(unsigned char *sha1, struct active_lock *lock)
+{
+	struct active_request_slot *slot;
+	char *out_data;
+	char *if_header;
+	struct buffer out_buffer;
+	struct curl_slist *dav_headers = NULL;
+	int i;
+
+	if_header = xmalloc(strlen(lock->token) + 25);
+	sprintf(if_header, "If: (<opaquelocktoken:%s>)", lock->token);
+	dav_headers = curl_slist_append(dav_headers, if_header);
+
+	out_buffer.size = 41;
+	out_data = xmalloc(out_buffer.size + 1);
+	i = snprintf(out_data, out_buffer.size + 1, "%s\n", sha1_to_hex(sha1));
+	if (i != out_buffer.size) {
+		fprintf(stderr, "Unable to initialize PUT request body\n");
+		return 0;
+	}
+	out_buffer.posn = 0;
+	out_buffer.buffer = out_data;
+
+	slot = get_active_slot();
+	curl_easy_setopt(slot->curl, CURLOPT_INFILE, &out_buffer);
+	curl_easy_setopt(slot->curl, CURLOPT_INFILESIZE, out_buffer.size);
+	curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, fread_buffer);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_null);
+	curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, DAV_PUT);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
+	curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 1);
+	curl_easy_setopt(slot->curl, CURLOPT_PUT, 1);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, lock->url);
+
+	if (start_active_slot(slot)) {
+		run_active_slot(slot);
+		free(out_data);
+		free(if_header);
+		if (slot->curl_result != CURLE_OK) {
+			fprintf(stderr,
+				"PUT error: curl result=%d, HTTP code=%ld\n",
+				slot->curl_result, slot->http_code);
+			/* We should attempt recovery? */
+			return 0;
+		}
+	} else {
+		free(out_data);
+		free(if_header);
+		fprintf(stderr, "Unable to start PUT request\n");
+		return 0;
+	}
+
+	return 1;
+}
+
+int main(int argc, char **argv)
+{
+	struct active_request_slot *slot;
+	struct active_request_slot *next_slot;
+	struct transfer_request *request;
+	struct transfer_request *next_request;
+	int nr_refspec = 0;
+	char **refspec = NULL;
+	int do_remote_update;
+	int new_branch;
+	int force_this;
+	char *local_ref;
+	unsigned char local_sha1[20];
+	struct object *local_object = NULL;
+	char *remote_ref = NULL;
+	unsigned char remote_sha1[20];
+	struct active_lock *remote_lock;
+	char *remote_path = NULL;
+	char *low_speed_limit;
+	char *low_speed_time;
+	int rc = 0;
+	int i;
+
+	setup_ident();
+
+	remote = xmalloc(sizeof(*remote));
+	remote->url = NULL;
+	remote->packs = NULL;
+
+	argv++;
+	for (i = 1; i < argc; i++, argv++) {
+		char *arg = *argv;
+
+		if (*arg == '-') {
+			if (!strcmp(arg, "--complete")) {
+				push_all = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--force")) {
+				force_all = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--verbose")) {
+				push_verbosely = 1;
+				continue;
+			}
+			usage(http_push_usage);
+		}
+		if (!remote->url) {
+			remote->url = arg;
+			continue;
+		}
+		refspec = argv;
+		nr_refspec = argc - i;
+		break;
+	}
+
+	curl_global_init(CURL_GLOBAL_ALL);
+
+#ifdef USE_CURL_MULTI
+	{
+		char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
+		if (http_max_requests != NULL)
+			max_requests = atoi(http_max_requests);
+	}
+
+	curlm = curl_multi_init();
+	if (curlm == NULL) {
+		fprintf(stderr, "Error creating curl multi handle.\n");
+		return 1;
+	}
+#endif
+
+	if (getenv("GIT_SSL_NO_VERIFY"))
+		curl_ssl_verify = 0;
+
+	ssl_cert = getenv("GIT_SSL_CERT");
+#if LIBCURL_VERSION_NUM >= 0x070902
+	ssl_key = getenv("GIT_SSL_KEY");
+#endif
+#if LIBCURL_VERSION_NUM >= 0x070908
+	ssl_capath = getenv("GIT_SSL_CAPATH");
+#endif
+	ssl_cainfo = getenv("GIT_SSL_CAINFO");
+
+	low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
+	if (low_speed_limit != NULL)
+		curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
+	low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
+	if (low_speed_time != NULL)
+		curl_low_speed_time = strtol(low_speed_time, NULL, 10);
+
+	git_config(http_options);
+
+	if (curl_ssl_verify == -1)
+		curl_ssl_verify = 1;
+
+#ifdef USE_CURL_MULTI
+	if (max_requests < 1)
+		max_requests = DEFAULT_MAX_REQUESTS;
+#endif
+
+	no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
+	default_headers = curl_slist_append(default_headers, "Range:");
+	default_headers = curl_slist_append(default_headers, "Destination:");
+	default_headers = curl_slist_append(default_headers, "If:");
+	default_headers = curl_slist_append(default_headers,
+					    "Pragma: no-cache");
+
+#ifndef NO_CURL_EASY_DUPHANDLE
+	curl_default = get_curl_handle();
+#endif
+
+	/* Verify DAV compliance/lock support */
+	if (check_locking() != 0) {
+		fprintf(stderr, "Error: no DAV locking support on remote repo %s\n", remote->url);
+		rc = 1;
+		goto cleanup;
+	}
+
+	/* Process each refspec */
+	for (i = 0; i < nr_refspec; i++) {
+		char *ep;
+		force_this = 0;
+		do_remote_update = 0;
+		new_branch = 0;
+		local_ref = refspec[i];
+		if (*local_ref == '+') {
+			force_this = 1;
+			local_ref++;
+		}
+		ep = strchr(local_ref, ':');
+		if (ep) {
+			remote_ref = ep + 1;
+			*ep = 0;
+		}
+		else
+			remote_ref = local_ref;
+
+		/* Lock remote branch ref */
+		if (remote_path)
+			free(remote_path);
+		remote_path = xmalloc(strlen(remote_ref) + 12);
+		sprintf(remote_path, "refs/heads/%s", remote_ref);
+		remote_lock = lock_remote(remote_path, LOCK_TIME);
+		if (remote_lock == NULL) {
+			fprintf(stderr, "Unable to lock remote branch %s\n",
+				remote_ref);
+			rc = 1;
+			continue;
+		}
+
+		/* Resolve local and remote refs */
+		if (fetch_ref(remote_ref, remote_sha1) != 0) {
+			fprintf(stderr,
+				"Remote branch %s does not exist on %s\n",
+				remote_ref, remote->url);
+			new_branch = 1;
+		}
+		if (get_sha1(local_ref, local_sha1) != 0) {
+			fprintf(stderr, "Error resolving local branch %s\n",
+				local_ref);
+			rc = 1;
+			goto unlock;
+		}
+	
+		/* Find relationship between local and remote */
+		local_object = parse_object(local_sha1);
+		if (!local_object) {
+			fprintf(stderr, "Unable to parse local object %s\n",
+				sha1_to_hex(local_sha1));
+			rc = 1;
+			goto unlock;
+		} else if (new_branch) {
+			do_remote_update = 1;
+		} else {
+			if (!memcmp(local_sha1, remote_sha1, 20)) {
+				fprintf(stderr,
+					"* %s: same as branch '%s' of %s\n",
+					local_ref, remote_ref, remote->url);
+			} else if (is_ancestor(remote_sha1,
+					       (struct commit *)local_object)) {
+				fprintf(stderr,
+					"Remote %s will fast-forward to local %s\n",
+					remote_ref, local_ref);
+				do_remote_update = 1;
+			} else if (force_all || force_this) {
+				fprintf(stderr,
+					"* %s on %s does not fast forward to local branch '%s', overwriting\n",
+					remote_ref, remote->url, local_ref);
+				do_remote_update = 1;
+			} else {
+				fprintf(stderr,
+					"* %s on %s does not fast forward to local branch '%s'\n",
+					remote_ref, remote->url, local_ref);
+				rc = 1;
+				goto unlock;
+			}
+		}
+
+		/* Generate and check list of required objects */
+		pushing = 0;
+		if (do_remote_update || push_all)
+			fetch_indices();
+		get_delta(push_all ? NULL : remote_sha1,
+			  local_object, remote_lock);
+		process_waiting_requests();
+
+		/* Push missing objects to remote, this would be a
+		   convenient time to pack them first if appropriate. */
+		pushing = 1;
+		process_request_queue();
+		process_waiting_requests();
+
+		/* Update the remote branch if all went well */
+		if (do_remote_update) {
+			if (!aborted && update_remote(local_sha1,
+						      remote_lock)) {
+				fprintf(stderr, "%s remote branch %s\n",
+					new_branch ? "Created" : "Updated",
+					remote_ref);
+			} else {
+				fprintf(stderr,
+					"Unable to %s remote branch %s\n",
+					new_branch ? "create" : "update",
+					remote_ref);
+				rc = 1;
+				goto unlock;
+			}
+		}
+
+	unlock:
+		unlock_remote(remote_lock);
+		free(remote_path);
+	}
+
+ cleanup:
+	free(remote);
+
+	curl_slist_free_all(no_pragma_header);
+	curl_slist_free_all(default_headers);
+
+	slot = active_queue_head;
+	while (slot != NULL) {
+		next_slot = slot->next;
+		if (slot->curl != NULL)
+			curl_easy_cleanup(slot->curl);
+		free(slot);
+		slot = next_slot;
+	}
+
+	request = request_queue_head;
+	while (request != NULL) {
+		next_request = request->next;
+		release_request(request);
+		request = next_request;
+	}
+
+#ifndef NO_CURL_EASY_DUPHANDLE
+	curl_easy_cleanup(curl_default);
+#endif
+#ifdef USE_CURL_MULTI
+	curl_multi_cleanup(curlm);
+#endif
+	curl_global_cleanup();
+	return rc;
+}