http-push.c - jrn/git - Git at Google

 #include "git-compat-util.h"
 #include "environment.h"
 #include "hex.h"
 #include "repository.h"
 #include "commit.h"
 #include "tag.h"
 #include "blob.h"
 #include "http.h"
 #include "diff.h"
 #include "revision.h"
 #include "remote.h"
 #include "list-objects.h"
 #include "setup.h"
 #include "sigchain.h"
 #include "strvec.h"
 #include "tree.h"
 #include "tree-walk.h"
 #include "url.h"
 #include "packfile.h"
 #include "object-store-ll.h"
 #include "commit-reach.h"

 #ifdef EXPAT_NEEDS_XMLPARSE_H
 #include <xmlparse.h>
 #else
 #include <expat.h>
 #endif

 static const char http_push_usage[] =
 "git http-push [--all] [--dry-run] [--force] [--verbose] <remote> [<head>...]\n";

 #ifndef XML_STATUS_OK
 enum XML_Status {
   XML_STATUS_OK = 1,
   XML_STATUS_ERROR = 0
 };
 #define XML_STATUS_OK    1
 #define XML_STATUS_ERROR 0
 #endif

 #define PREV_BUF_SIZE 4096

 /* DAV methods */
 #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 DAV_DELETE "DELETE"

 /* DAV lock flags */
 #define DAV_PROP_LOCKWR (1u << 0)
 #define DAV_PROP_LOCKEX (1u << 1)
 #define DAV_LOCK_OK (1u << 2)

 /* DAV XML properties */
 #define DAV_CTX_LOCKENTRY ".multistatus.response.propstat.prop.supportedlock.lockentry"
 #define DAV_CTX_LOCKTYPE_WRITE ".multistatus.response.propstat.prop.supportedlock.lockentry.locktype.write"
 #define DAV_CTX_LOCKTYPE_EXCLUSIVE ".multistatus.response.propstat.prop.supportedlock.lockentry.lockscope.exclusive"
 #define DAV_ACTIVELOCK_OWNER ".prop.lockdiscovery.activelock.owner.href"
 #define DAV_ACTIVELOCK_TIMEOUT ".prop.lockdiscovery.activelock.timeout"
 #define DAV_ACTIVELOCK_TOKEN ".prop.lockdiscovery.activelock.locktoken.href"
 #define DAV_PROPFIND_RESP ".multistatus.response"
 #define DAV_PROPFIND_NAME ".multistatus.response.href"
 #define DAV_PROPFIND_COLLECTION ".multistatus.response.propstat.prop.resourcetype.collection"

 /* DAV request body templates */
 #define PROPFIND_SUPPORTEDLOCK_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 PROPFIND_ALL_REQUEST "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:allprop/>\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

 /* Remember to update object flag allocation in object.h */
 #define LOCAL    (1u<<11)
 #define REMOTE   (1u<<12)
 #define FETCHING (1u<<13)
 #define PUSHING  (1u<<14)

 /* We allow "recursive" symbolic refs. Only within reason, though */
 #define MAXDEPTH 5

 static int pushing;
 static int aborted;
 static signed char remote_dir_exists[256];

 static int push_verbosely;
 static int push_all = MATCH_REFS_NONE;
 static int force_all;
 static int dry_run;
 static int helper_status;

 static struct object_list *objects;

 struct repo {
 	char *url;
 	char *path;
 	int path_len;
 	int has_info_refs;
 	int can_update_info_refs;
 	int has_info_packs;
 	struct packed_git *packs;
 	struct remote_lock *locks;
 };

 static struct repo *repo;

 enum transfer_state {
 	NEED_FETCH,
 	RUN_FETCH_LOOSE,
 	RUN_FETCH_PACKED,
 	NEED_PUSH,
 	RUN_MKCOL,
 	RUN_PUT,
 	RUN_MOVE,
 	ABORTED,
 	COMPLETE
 };

 struct transfer_request {
 	struct object *obj;
 	struct packed_git *target;
 	char *url;
 	char *dest;
 	struct remote_lock *lock;
 	struct curl_slist *headers;
 	struct buffer buffer;
 	enum transfer_state state;
 	CURLcode curl_result;
 	char errorstr[CURL_ERROR_SIZE];
 	long http_code;
 	void *userData;
 	struct active_request_slot *slot;
 	struct transfer_request *next;
 };

 static struct transfer_request *request_queue_head;

 struct xml_ctx {
 	char *name;
 	int len;
 	char *cdata;
 	void (*userFunc)(struct xml_ctx *ctx, int tag_closed);
 	void *userData;
 };

 struct remote_lock {
 	char *url;
 	char *owner;
 	char *token;
 	char tmpfile_suffix[GIT_MAX_HEXSZ + 1];
 	time_t start_time;
 	long timeout;
 	int refreshing;
 	struct remote_lock *next;
 };

 /* Flags that control remote_ls processing */
 #define PROCESS_FILES (1u << 0)
 #define PROCESS_DIRS  (1u << 1)
 #define RECURSIVE     (1u << 2)

 /* Flags that remote_ls passes to callback functions */
 #define IS_DIR (1u << 0)

 struct remote_ls_ctx {
 	char *path;
 	void (*userFunc)(struct remote_ls_ctx *ls);
 	void *userData;
 	int flags;
 	char *dentry_name;
 	int dentry_flags;
 	struct remote_ls_ctx *parent;
 };

 /* get_dav_token_headers options */
 enum dav_header_flag {
 	DAV_HEADER_IF = (1u << 0),
 	DAV_HEADER_LOCK = (1u << 1),
 	DAV_HEADER_TIMEOUT = (1u << 2)
 };

 static char *xml_entities(const char *s)
 {
 	struct strbuf buf = STRBUF_INIT;
 	strbuf_addstr_xml_quoted(&buf, s);
 	return strbuf_detach(&buf, NULL);
 }

 static void curl_setup_http_get(CURL *curl, const char *url,
 		const char *custom_req)
 {
 	curl_easy_setopt(curl, CURLOPT_HTTPGET, 1);
 	curl_easy_setopt(curl, CURLOPT_URL, url);
 	curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, custom_req);
 	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_null);
 }

 static void curl_setup_http(CURL *curl, const char *url,
 		const char *custom_req, struct buffer *buffer,
 		curl_write_callback write_fn)
 {
 	curl_easy_setopt(curl, CURLOPT_UPLOAD, 1);
 	curl_easy_setopt(curl, CURLOPT_URL, url);
 	curl_easy_setopt(curl, CURLOPT_INFILE, buffer);
 	curl_easy_setopt(curl, CURLOPT_INFILESIZE, buffer->buf.len);
 	curl_easy_setopt(curl, CURLOPT_READFUNCTION, fread_buffer);
 	curl_easy_setopt(curl, CURLOPT_SEEKFUNCTION, seek_buffer);
 	curl_easy_setopt(curl, CURLOPT_SEEKDATA, buffer);
 	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_fn);
 	curl_easy_setopt(curl, CURLOPT_NOBODY, 0);
 	curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, custom_req);
 	curl_easy_setopt(curl, CURLOPT_UPLOAD, 1);
 }

 static struct curl_slist *get_dav_token_headers(struct remote_lock *lock, enum dav_header_flag options)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct curl_slist *dav_headers = http_copy_default_headers();

 	if (options & DAV_HEADER_IF) {
 		strbuf_addf(&buf, "If: (<%s>)", lock->token);
 		dav_headers = curl_slist_append(dav_headers, buf.buf);
 		strbuf_reset(&buf);
 	}
 	if (options & DAV_HEADER_LOCK) {
 		strbuf_addf(&buf, "Lock-Token: <%s>", lock->token);
 		dav_headers = curl_slist_append(dav_headers, buf.buf);
 		strbuf_reset(&buf);
 	}
 	if (options & DAV_HEADER_TIMEOUT) {
 		strbuf_addf(&buf, "Timeout: Second-%ld", lock->timeout);
 		dav_headers = curl_slist_append(dav_headers, buf.buf);
 		strbuf_reset(&buf);
 	}
 	strbuf_release(&buf);

 	return dav_headers;
 }

 static void finish_request(struct transfer_request *request);
 static void release_request(struct transfer_request *request);

 static void process_response(void *callback_data)
 {
 	struct transfer_request *request =
 		(struct transfer_request *)callback_data;

 	finish_request(request);
 }

 static void start_fetch_loose(struct transfer_request *request)
 {
 	struct active_request_slot *slot;
 	struct http_object_request *obj_req;

 	obj_req = new_http_object_request(repo->url, &request->obj->oid);
 	if (!obj_req) {
 		request->state = ABORTED;
 		return;
 	}

 	slot = obj_req->slot;
 	slot->callback_func = process_response;
 	slot->callback_data = request;
 	request->slot = slot;
 	request->userData = obj_req;

 	/* Try to get the request started, abort the request on error */
 	request->state = RUN_FETCH_LOOSE;
 	if (!start_active_slot(slot)) {
 		fprintf(stderr, "Unable to start GET request\n");
 		repo->can_update_info_refs = 0;
 		release_http_object_request(obj_req);
 		release_request(request);
 	}
 }

 static void start_mkcol(struct transfer_request *request)
 {
 	char *hex = oid_to_hex(&request->obj->oid);
 	struct active_request_slot *slot;

 	request->url = get_remote_object_url(repo->url, hex, 1);

 	slot = get_active_slot();
 	slot->callback_func = process_response;
 	slot->callback_data = request;
 	curl_setup_http_get(slot->curl, request->url, DAV_MKCOL);
 	curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, request->errorstr);

 	if (start_active_slot(slot)) {
 		request->slot = slot;
 		request->state = RUN_MKCOL;
 	} else {
 		request->state = ABORTED;
 		FREE_AND_NULL(request->url);
 	}
 }

 static void start_fetch_packed(struct transfer_request *request)
 {
 	struct packed_git *target;

 	struct transfer_request *check_request = request_queue_head;
 	struct http_pack_request *preq;

 	target = find_sha1_pack(request->obj->oid.hash, repo->packs);
 	if (!target) {
 		fprintf(stderr, "Unable to fetch %s, will not be able to update server info refs\n", oid_to_hex(&request->obj->oid));
 		repo->can_update_info_refs = 0;
 		release_request(request);
 		return;
 	}
 	close_pack_index(target);
 	request->target = target;

 	fprintf(stderr,	"Fetching pack %s\n",
 		hash_to_hex(target->hash));
 	fprintf(stderr, " which contains %s\n", oid_to_hex(&request->obj->oid));

 	preq = new_http_pack_request(target->hash, repo->url);
 	if (!preq) {
 		repo->can_update_info_refs = 0;
 		return;
 	}

 	/* Make sure there isn't another open request for this pack */
 	while (check_request) {
 		if (check_request->state == RUN_FETCH_PACKED &&
 		    !strcmp(check_request->url, preq->url)) {
 			release_http_pack_request(preq);
 			release_request(request);
 			return;
 		}
 		check_request = check_request->next;
 	}

 	preq->slot->callback_func = process_response;
 	preq->slot->callback_data = request;
 	request->slot = preq->slot;
 	request->userData = preq;

 	/* Try to get the request started, abort the request on error */
 	request->state = RUN_FETCH_PACKED;
 	if (!start_active_slot(preq->slot)) {
 		fprintf(stderr, "Unable to start GET request\n");
 		release_http_pack_request(preq);
 		repo->can_update_info_refs = 0;
 		release_request(request);
 	}
 }

 static void start_put(struct transfer_request *request)
 {
 	char *hex = oid_to_hex(&request->obj->oid);
 	struct active_request_slot *slot;
 	struct strbuf buf = STRBUF_INIT;
 	enum object_type type;
 	char hdr[50];
 	void *unpacked;
 	unsigned long len;
 	int hdrlen;
 	ssize_t size;
 	git_zstream stream;

 	unpacked = repo_read_object_file(the_repository, &request->obj->oid,
 					 &type, &len);
 	hdrlen = format_object_header(hdr, sizeof(hdr), type, len);

 	/* Set it up */
 	git_deflate_init(&stream, zlib_compression_level);
 	size = git_deflate_bound(&stream, len + hdrlen);
 	strbuf_init(&request->buffer.buf, size);
 	request->buffer.posn = 0;

 	/* Compress it */
 	stream.next_out = (unsigned char *)request->buffer.buf.buf;
 	stream.avail_out = size;

 	/* First header.. */
 	stream.next_in = (void *)hdr;
 	stream.avail_in = hdrlen;
 	while (git_deflate(&stream, 0) == Z_OK)
 		; /* nothing */

 	/* Then the data itself.. */
 	stream.next_in = unpacked;
 	stream.avail_in = len;
 	while (git_deflate(&stream, Z_FINISH) == Z_OK)
 		; /* nothing */
 	git_deflate_end(&stream);
 	free(unpacked);

 	request->buffer.buf.len = stream.total_out;

 	strbuf_addstr(&buf, "Destination: ");
 	append_remote_object_url(&buf, repo->url, hex, 0);
 	request->dest = strbuf_detach(&buf, NULL);

 	append_remote_object_url(&buf, repo->url, hex, 0);
 	strbuf_add(&buf, request->lock->tmpfile_suffix, the_hash_algo->hexsz + 1);
 	request->url = strbuf_detach(&buf, NULL);

 	slot = get_active_slot();
 	slot->callback_func = process_response;
 	slot->callback_data = request;
 	curl_setup_http(slot->curl, request->url, DAV_PUT,
 			&request->buffer, fwrite_null);

 	if (start_active_slot(slot)) {
 		request->slot = slot;
 		request->state = RUN_PUT;
 	} else {
 		request->state = ABORTED;
 		FREE_AND_NULL(request->url);
 	}
 }

 static void start_move(struct transfer_request *request)
 {
 	struct active_request_slot *slot;
 	struct curl_slist *dav_headers = http_copy_default_headers();

 	slot = get_active_slot();
 	slot->callback_func = process_response;
 	slot->callback_data = request;
 	curl_setup_http_get(slot->curl, request->url, 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);

 	if (start_active_slot(slot)) {
 		request->slot = slot;
 		request->state = RUN_MOVE;
 	} else {
 		request->state = ABORTED;
 		FREE_AND_NULL(request->url);
 	}
 }

 static int refresh_lock(struct remote_lock *lock)
 {
 	struct active_request_slot *slot;
 	struct slot_results results;
 	struct curl_slist *dav_headers;
 	int rc = 0;

 	lock->refreshing = 1;

 	dav_headers = get_dav_token_headers(lock, DAV_HEADER_IF | DAV_HEADER_TIMEOUT);

 	slot = get_active_slot();
 	slot->results = &results;
 	curl_setup_http_get(slot->curl, lock->url, DAV_LOCK);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);

 	if (start_active_slot(slot)) {
 		run_active_slot(slot);
 		if (results.curl_result != CURLE_OK) {
 			fprintf(stderr, "LOCK HTTP error %ld\n",
 				results.http_code);
 		} else {
 			lock->start_time = time(NULL);
 			rc = 1;
 		}
 	}

 	lock->refreshing = 0;
 	curl_slist_free_all(dav_headers);

 	return rc;
 }

 static void check_locks(void)
 {
 	struct remote_lock *lock = repo->locks;
 	time_t current_time = time(NULL);
 	int time_remaining;

 	while (lock) {
 		time_remaining = lock->start_time + lock->timeout -
 			current_time;
 		if (!lock->refreshing && time_remaining < LOCK_REFRESH) {
 			if (!refresh_lock(lock)) {
 				fprintf(stderr,
 					"Unable to refresh lock for %s\n",
 					lock->url);
 				aborted = 1;
 				return;
 			}
 		}
 		lock = lock->next;
 	}
 }

 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 && entry->next != request)
 			entry = entry->next;
 		if (entry)
 			entry->next = request->next;
 	}

 	free(request->url);
 	free(request);
 }

 static void finish_request(struct transfer_request *request)
 {
 	struct http_pack_request *preq;
 	struct http_object_request *obj_req;

 	request->curl_result = request->slot->curl_result;
 	request->http_code = request->slot->http_code;
 	request->slot = NULL;

 	/* Keep locks active */
 	check_locks();

 	if (request->headers)
 		curl_slist_free_all(request->headers);

 	/* URL is reused for MOVE after PUT and used during FETCH */
 	if (request->state != RUN_PUT && request->state != RUN_FETCH_PACKED) {
 		FREE_AND_NULL(request->url);
 	}

 	if (request->state == RUN_MKCOL) {
 		if (request->curl_result == CURLE_OK ||
 		    request->http_code == 405) {
 			remote_dir_exists[request->obj->oid.hash[0]] = 1;
 			start_put(request);
 		} else {
 			fprintf(stderr, "MKCOL %s failed, aborting (%d/%ld)\n",
 				oid_to_hex(&request->obj->oid),
 				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",
 				oid_to_hex(&request->obj->oid),
 				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",
 					oid_to_hex(&request->obj->oid));
 			request->obj->flags |= REMOTE;
 			release_request(request);
 		} else {
 			fprintf(stderr, "MOVE %s failed, aborting (%d/%ld)\n",
 				oid_to_hex(&request->obj->oid),
 				request->curl_result, request->http_code);
 			request->state = ABORTED;
 			aborted = 1;
 		}
 	} else if (request->state == RUN_FETCH_LOOSE) {
 		obj_req = (struct http_object_request *)request->userData;

 		if (finish_http_object_request(obj_req) == 0)
 			if (obj_req->rename == 0)
 				request->obj->flags |= (LOCAL | REMOTE);

 		/* Try fetching packed if necessary */
 		if (request->obj->flags & LOCAL) {
 			release_http_object_request(obj_req);
 			release_request(request);
 		} else
 			start_fetch_packed(request);

 	} else if (request->state == RUN_FETCH_PACKED) {
 		int fail = 1;
 		if (request->curl_result != CURLE_OK) {
 			fprintf(stderr, "Unable to get pack file %s\n%s",
 				request->url, curl_errorstr);
 		} else {
 			preq = (struct http_pack_request *)request->userData;

 			if (preq) {
 				if (finish_http_pack_request(preq) == 0)
 					fail = 0;
 				release_http_pack_request(preq);
 			}
 		}
 		if (fail)
 			repo->can_update_info_refs = 0;
 		else
 			http_install_packfile(request->target, &repo->packs);
 		release_request(request);
 	}
 }

 static int is_running_queue;
 static int fill_active_slot(void *data UNUSED)
 {
 	struct transfer_request *request;

 	if (aborted || !is_running_queue)
 		return 0;

 	for (request = request_queue_head; request; request = request->next) {
 		if (request->state == NEED_FETCH) {
 			start_fetch_loose(request);
 			return 1;
 		} else if (pushing && request->state == NEED_PUSH) {
 			if (remote_dir_exists[request->obj->oid.hash[0]] == 1) {
 				start_put(request);
 			} else {
 				start_mkcol(request);
 			}
 			return 1;
 		}
 	}
 	return 0;
 }

 static void get_remote_object_list(unsigned char parent);

 static void add_fetch_request(struct object *obj)
 {
 	struct transfer_request *request;

 	check_locks();

 	/*
 	 * Don't fetch the object if it's known to exist locally
 	 * or is already in the request queue
 	 */
 	if (remote_dir_exists[obj->oid.hash[0]] == -1)
 		get_remote_object_list(obj->oid.hash[0]);
 	if (obj->flags & (LOCAL | FETCHING))
 		return;

 	obj->flags |= FETCHING;
 	request = xmalloc(sizeof(*request));
 	request->obj = obj;
 	request->url = NULL;
 	request->lock = NULL;
 	request->headers = NULL;
 	request->state = NEED_FETCH;
 	request->next = request_queue_head;
 	request_queue_head = request;

 	fill_active_slots();
 	step_active_slots();
 }

 static int add_send_request(struct object *obj, struct remote_lock *lock)
 {
 	struct transfer_request *request;
 	struct packed_git *target;

 	/* Keep locks active */
 	check_locks();

 	/*
 	 * Don't push the object if it's known to exist on the remote
 	 * or is already in the request queue
 	 */
 	if (remote_dir_exists[obj->oid.hash[0]] == -1)
 		get_remote_object_list(obj->oid.hash[0]);
 	if (obj->flags & (REMOTE | PUSHING))
 		return 0;
 	target = find_sha1_pack(obj->oid.hash, repo->packs);
 	if (target) {
 		obj->flags |= REMOTE;
 		return 0;
 	}

 	obj->flags |= PUSHING;
 	request = xmalloc(sizeof(*request));
 	request->obj = obj;
 	request->url = NULL;
 	request->lock = lock;
 	request->headers = NULL;
 	request->state = NEED_PUSH;
 	request->next = request_queue_head;
 	request_queue_head = request;

 	fill_active_slots();
 	step_active_slots();

 	return 1;
 }

 static int fetch_indices(void)
 {
 	int ret;

 	if (push_verbosely)
 		fprintf(stderr, "Getting pack list\n");

 	switch (http_get_info_packs(repo->url, &repo->packs)) {
 	case HTTP_OK:
 	case HTTP_MISSING_TARGET:
 		ret = 0;
 		break;
 	default:
 		ret = -1;
 	}

 	return ret;
 }

 static void one_remote_object(const struct object_id *oid)
 {
 	struct object *obj;

 	obj = lookup_object(the_repository, oid);
 	if (!obj)
 		obj = parse_object(the_repository, oid);

 	/* Ignore remote objects that don't exist locally */
 	if (!obj)
 		return;

 	obj->flags |= REMOTE;
 	if (!object_list_contains(objects, obj))
 		object_list_insert(obj, &objects);
 }

 static void handle_lockprop_ctx(struct xml_ctx *ctx, int tag_closed)
 {
 	int *lock_flags = (int *)ctx->userData;

 	if (tag_closed) {
 		if (!strcmp(ctx->name, DAV_CTX_LOCKENTRY)) {
 			if ((*lock_flags & DAV_PROP_LOCKEX) &&
 			    (*lock_flags & DAV_PROP_LOCKWR)) {
 				*lock_flags |= DAV_LOCK_OK;
 			}
 			*lock_flags &= DAV_LOCK_OK;
 		} else if (!strcmp(ctx->name, DAV_CTX_LOCKTYPE_WRITE)) {
 			*lock_flags |= DAV_PROP_LOCKWR;
 		} else if (!strcmp(ctx->name, DAV_CTX_LOCKTYPE_EXCLUSIVE)) {
 			*lock_flags |= DAV_PROP_LOCKEX;
 		}
 	}
 }

 static void handle_new_lock_ctx(struct xml_ctx *ctx, int tag_closed)
 {
 	struct remote_lock *lock = (struct remote_lock *)ctx->userData;
 	git_hash_ctx hash_ctx;
 	unsigned char lock_token_hash[GIT_MAX_RAWSZ];

 	if (tag_closed && ctx->cdata) {
 		if (!strcmp(ctx->name, DAV_ACTIVELOCK_OWNER)) {
 			lock->owner = xstrdup(ctx->cdata);
 		} else if (!strcmp(ctx->name, DAV_ACTIVELOCK_TIMEOUT)) {
 			const char *arg;
 			if (skip_prefix(ctx->cdata, "Second-", &arg))
 				lock->timeout = strtol(arg, NULL, 10);
 		} else if (!strcmp(ctx->name, DAV_ACTIVELOCK_TOKEN)) {
 			lock->token = xstrdup(ctx->cdata);

 			the_hash_algo->init_fn(&hash_ctx);
 			the_hash_algo->update_fn(&hash_ctx, lock->token, strlen(lock->token));
 			the_hash_algo->final_fn(lock_token_hash, &hash_ctx);

 			lock->tmpfile_suffix[0] = '_';
 			memcpy(lock->tmpfile_suffix + 1, hash_to_hex(lock_token_hash), the_hash_algo->hexsz);
 		}
 	}
 }

 static void one_remote_ref(const char *refname);

 static void
 xml_start_tag(void *userData, const char *name, const char **atts UNUSED)
 {
 	struct xml_ctx *ctx = (struct xml_ctx *)userData;
 	const char *c = strchr(name, ':');
 	int old_namelen, new_len;

 	if (!c)
 		c = name;
 	else
 		c++;

 	old_namelen = strlen(ctx->name);
 	new_len = old_namelen + strlen(c) + 2;

 	if (new_len > ctx->len) {
 		ctx->name = xrealloc(ctx->name, new_len);
 		ctx->len = new_len;
 	}
 	xsnprintf(ctx->name + old_namelen, ctx->len - old_namelen, ".%s", c);

 	FREE_AND_NULL(ctx->cdata);

 	ctx->userFunc(ctx, 0);
 }

 static void
 xml_end_tag(void *userData, const char *name)
 {
 	struct xml_ctx *ctx = (struct xml_ctx *)userData;
 	const char *c = strchr(name, ':');
 	char *ep;

 	ctx->userFunc(ctx, 1);

 	if (!c)
 		c = name;
 	else
 		c++;

 	ep = ctx->name + strlen(ctx->name) - strlen(c) - 1;
 	*ep = 0;
 }

 static void
 xml_cdata(void *userData, const XML_Char *s, int len)
 {
 	struct xml_ctx *ctx = (struct xml_ctx *)userData;
 	free(ctx->cdata);
 	ctx->cdata = xmemdupz(s, len);
 }

 static struct remote_lock *lock_remote(const char *path, long timeout)
 {
 	struct active_request_slot *slot;
 	struct slot_results results;
 	struct buffer out_buffer = { STRBUF_INIT, 0 };
 	struct strbuf in_buffer = STRBUF_INIT;
 	char *url;
 	char *ep;
 	char timeout_header[25];
 	struct remote_lock *lock = NULL;
 	struct curl_slist *dav_headers = http_copy_default_headers();
 	struct xml_ctx ctx;
 	char *escaped;

 	url = xstrfmt("%s%s", repo->url, path);

 	/* Make sure leading directories exist for the remote ref */
 	ep = strchr(url + strlen(repo->url) + 1, '/');
 	while (ep) {
 		char saved_character = ep[1];
 		ep[1] = '\0';
 		slot = get_active_slot();
 		slot->results = &results;
 		curl_setup_http_get(slot->curl, url, DAV_MKCOL);
 		if (start_active_slot(slot)) {
 			run_active_slot(slot);
 			if (results.curl_result != CURLE_OK &&
 			    results.http_code != 405) {
 				fprintf(stderr,
 					"Unable to create branch path %s\n",
 					url);
 				free(url);
 				return NULL;
 			}
 		} else {
 			fprintf(stderr, "Unable to start MKCOL request\n");
 			free(url);
 			return NULL;
 		}
 		ep[1] = saved_character;
 		ep = strchr(ep + 1, '/');
 	}

 	escaped = xml_entities(ident_default_email());
 	strbuf_addf(&out_buffer.buf, LOCK_REQUEST, escaped);
 	free(escaped);

 	xsnprintf(timeout_header, sizeof(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();
 	slot->results = &results;
 	curl_setup_http(slot->curl, url, DAV_LOCK, &out_buffer, fwrite_buffer);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
 	curl_easy_setopt(slot->curl, CURLOPT_WRITEDATA, &in_buffer);

 	CALLOC_ARRAY(lock, 1);
 	lock->timeout = -1;

 	if (start_active_slot(slot)) {
 		run_active_slot(slot);
 		if (results.curl_result == CURLE_OK) {
 			XML_Parser parser = XML_ParserCreate(NULL);
 			enum XML_Status result;
 			ctx.name = xcalloc(10, 1);
 			ctx.len = 0;
 			ctx.cdata = NULL;
 			ctx.userFunc = handle_new_lock_ctx;
 			ctx.userData = lock;
 			XML_SetUserData(parser, &ctx);
 			XML_SetElementHandler(parser, xml_start_tag,
 					      xml_end_tag);
 			XML_SetCharacterDataHandler(parser, xml_cdata);
 			result = XML_Parse(parser, in_buffer.buf,
 					   in_buffer.len, 1);
 			free(ctx.name);
 			if (result != XML_STATUS_OK) {
 				fprintf(stderr, "XML error: %s\n",
 					XML_ErrorString(
 						XML_GetErrorCode(parser)));
 				lock->timeout = -1;
 			}
 			XML_ParserFree(parser);
 		} else {
 			fprintf(stderr,
 				"error: curl result=%d, HTTP code=%ld\n",
 				results.curl_result, results.http_code);
 		}
 	} else {
 		fprintf(stderr, "Unable to start LOCK request\n");
 	}

 	curl_slist_free_all(dav_headers);
 	strbuf_release(&out_buffer.buf);
 	strbuf_release(&in_buffer);

 	if (lock->token == NULL || lock->timeout <= 0) {
 		free(lock->token);
 		free(lock->owner);
 		free(url);
 		FREE_AND_NULL(lock);
 	} else {
 		lock->url = url;
 		lock->start_time = time(NULL);
 		lock->next = repo->locks;
 		repo->locks = lock;
 	}

 	return lock;
 }

 static int unlock_remote(struct remote_lock *lock)
 {
 	struct active_request_slot *slot;
 	struct slot_results results;
 	struct remote_lock *prev = repo->locks;
 	struct curl_slist *dav_headers;
 	int rc = 0;

 	dav_headers = get_dav_token_headers(lock, DAV_HEADER_LOCK);

 	slot = get_active_slot();
 	slot->results = &results;
 	curl_setup_http_get(slot->curl, lock->url, DAV_UNLOCK);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);

 	if (start_active_slot(slot)) {
 		run_active_slot(slot);
 		if (results.curl_result == CURLE_OK)
 			rc = 1;
 		else
 			fprintf(stderr, "UNLOCK HTTP error %ld\n",
 				results.http_code);
 	} else {
 		fprintf(stderr, "Unable to start UNLOCK request\n");
 	}

 	curl_slist_free_all(dav_headers);

 	if (repo->locks == lock) {
 		repo->locks = lock->next;
 	} else {
 		while (prev && prev->next != lock)
 			prev = prev->next;
 		if (prev)
 			prev->next = lock->next;
 	}

 	free(lock->owner);
 	free(lock->url);
 	free(lock->token);
 	free(lock);

 	return rc;
 }

 static void remove_locks(void)
 {
 	struct remote_lock *lock = repo->locks;

 	fprintf(stderr, "Removing remote locks...\n");
 	while (lock) {
 		struct remote_lock *next = lock->next;
 		unlock_remote(lock);
 		lock = next;
 	}
 }

 static void remove_locks_on_signal(int signo)
 {
 	remove_locks();
 	sigchain_pop(signo);
 	raise(signo);
 }

 static void remote_ls(const char *path, int flags,
 		      void (*userFunc)(struct remote_ls_ctx *ls),
 		      void *userData);

 /* extract hex from sharded "xx/x{38}" filename */
 static int get_oid_hex_from_objpath(const char *path, struct object_id *oid)
 {
 	oid->algo = hash_algo_by_ptr(the_hash_algo);

 	if (strlen(path) != the_hash_algo->hexsz + 1)
 		return -1;

 	if (hex_to_bytes(oid->hash, path, 1))
 		return -1;
 	path += 2;
 	path++; /* skip '/' */

 	return hex_to_bytes(oid->hash + 1, path, the_hash_algo->rawsz - 1);
 }

 static void process_ls_object(struct remote_ls_ctx *ls)
 {
 	unsigned int *parent = (unsigned int *)ls->userData;
 	const char *path = ls->dentry_name;
 	struct object_id oid;

 	if (!strcmp(ls->path, ls->dentry_name) && (ls->flags & IS_DIR)) {
 		remote_dir_exists[*parent] = 1;
 		return;
 	}

 	if (!skip_prefix(path, "objects/", &path) ||
 	    get_oid_hex_from_objpath(path, &oid))
 		return;

 	one_remote_object(&oid);
 }

 static void process_ls_ref(struct remote_ls_ctx *ls)
 {
 	if (!strcmp(ls->path, ls->dentry_name) && (ls->dentry_flags & IS_DIR)) {
 		fprintf(stderr, "  %s\n", ls->dentry_name);
 		return;
 	}

 	if (!(ls->dentry_flags & IS_DIR))
 		one_remote_ref(ls->dentry_name);
 }

 static void handle_remote_ls_ctx(struct xml_ctx *ctx, int tag_closed)
 {
 	struct remote_ls_ctx *ls = (struct remote_ls_ctx *)ctx->userData;

 	if (tag_closed) {
 		if (!strcmp(ctx->name, DAV_PROPFIND_RESP) && ls->dentry_name) {
 			if (ls->dentry_flags & IS_DIR) {

 				/* ensure collection names end with slash */
 				str_end_url_with_slash(ls->dentry_name, &ls->dentry_name);

 				if (ls->flags & PROCESS_DIRS) {
 					ls->userFunc(ls);
 				}
 				if (strcmp(ls->dentry_name, ls->path) &&
 				    ls->flags & RECURSIVE) {
 					remote_ls(ls->dentry_name,
 						  ls->flags,
 						  ls->userFunc,
 						  ls->userData);
 				}
 			} else if (ls->flags & PROCESS_FILES) {
 				ls->userFunc(ls);
 			}
 		} else if (!strcmp(ctx->name, DAV_PROPFIND_NAME) && ctx->cdata) {
 			char *path = ctx->cdata;
 			if (*ctx->cdata == 'h') {
 				path = strstr(path, "//");
 				if (path) {
 					path = strchr(path+2, '/');
 				}
 			}
 			if (path) {
 				const char *url = repo->url;
 				if (repo->path)
 					url = repo->path;
 				if (strncmp(path, url, repo->path_len))
 					error("Parsed path '%s' does not match url: '%s'",
 					      path, url);
 				else {
 					path += repo->path_len;
 					ls->dentry_name = xstrdup(path);
 				}
 			}
 		} else if (!strcmp(ctx->name, DAV_PROPFIND_COLLECTION)) {
 			ls->dentry_flags |= IS_DIR;
 		}
 	} else if (!strcmp(ctx->name, DAV_PROPFIND_RESP)) {
 		FREE_AND_NULL(ls->dentry_name);
 		ls->dentry_flags = 0;
 	}
 }

 /*
  * NEEDSWORK: remote_ls() ignores info/refs on the remote side.  But it
  * should _only_ heed the information from that file, instead of trying to
  * determine the refs from the remote file system (badly: it does not even
  * know about packed-refs).
  */
 static void remote_ls(const char *path, int flags,
 		      void (*userFunc)(struct remote_ls_ctx *ls),
 		      void *userData)
 {
 	char *url = xstrfmt("%s%s", repo->url, path);
 	struct active_request_slot *slot;
 	struct slot_results results;
 	struct strbuf in_buffer = STRBUF_INIT;
 	struct buffer out_buffer = { STRBUF_INIT, 0 };
 	struct curl_slist *dav_headers = http_copy_default_headers();
 	struct xml_ctx ctx;
 	struct remote_ls_ctx ls;

 	ls.flags = flags;
 	ls.path = xstrdup(path);
 	ls.dentry_name = NULL;
 	ls.dentry_flags = 0;
 	ls.userData = userData;
 	ls.userFunc = userFunc;

 	strbuf_addstr(&out_buffer.buf, PROPFIND_ALL_REQUEST);

 	dav_headers = curl_slist_append(dav_headers, "Depth: 1");
 	dav_headers = curl_slist_append(dav_headers, "Content-Type: text/xml");

 	slot = get_active_slot();
 	slot->results = &results;
 	curl_setup_http(slot->curl, url, DAV_PROPFIND,
 			&out_buffer, fwrite_buffer);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
 	curl_easy_setopt(slot->curl, CURLOPT_WRITEDATA, &in_buffer);

 	if (start_active_slot(slot)) {
 		run_active_slot(slot);
 		if (results.curl_result == CURLE_OK) {
 			XML_Parser parser = XML_ParserCreate(NULL);
 			enum XML_Status result;
 			ctx.name = xcalloc(10, 1);
 			ctx.len = 0;
 			ctx.cdata = NULL;
 			ctx.userFunc = handle_remote_ls_ctx;
 			ctx.userData = &ls;
 			XML_SetUserData(parser, &ctx);
 			XML_SetElementHandler(parser, xml_start_tag,
 					      xml_end_tag);
 			XML_SetCharacterDataHandler(parser, xml_cdata);
 			result = XML_Parse(parser, in_buffer.buf,
 					   in_buffer.len, 1);
 			free(ctx.name);

 			if (result != XML_STATUS_OK) {
 				fprintf(stderr, "XML error: %s\n",
 					XML_ErrorString(
 						XML_GetErrorCode(parser)));
 			}
 			XML_ParserFree(parser);
 		}
 	} else {
 		fprintf(stderr, "Unable to start PROPFIND request\n");
 	}

 	free(ls.path);
 	free(url);
 	strbuf_release(&out_buffer.buf);
 	strbuf_release(&in_buffer);
 	curl_slist_free_all(dav_headers);
 }

 static void get_remote_object_list(unsigned char parent)
 {
 	char path[] = "objects/XX/";
 	static const char hex[] = "0123456789abcdef";
 	unsigned int val = parent;

 	path[8] = hex[val >> 4];
 	path[9] = hex[val & 0xf];
 	remote_dir_exists[val] = 0;
 	remote_ls(path, (PROCESS_FILES | PROCESS_DIRS),
 		  process_ls_object, &val);
 }

 static int locking_available(void)
 {
 	struct active_request_slot *slot;
 	struct slot_results results;
 	struct strbuf in_buffer = STRBUF_INIT;
 	struct buffer out_buffer = { STRBUF_INIT, 0 };
 	struct curl_slist *dav_headers = http_copy_default_headers();
 	struct xml_ctx ctx;
 	int lock_flags = 0;
 	char *escaped;

 	escaped = xml_entities(repo->url);
 	strbuf_addf(&out_buffer.buf, PROPFIND_SUPPORTEDLOCK_REQUEST, escaped);
 	free(escaped);

 	dav_headers = curl_slist_append(dav_headers, "Depth: 0");
 	dav_headers = curl_slist_append(dav_headers, "Content-Type: text/xml");

 	slot = get_active_slot();
 	slot->results = &results;
 	curl_setup_http(slot->curl, repo->url, DAV_PROPFIND,
 			&out_buffer, fwrite_buffer);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
 	curl_easy_setopt(slot->curl, CURLOPT_WRITEDATA, &in_buffer);

 	if (start_active_slot(slot)) {
 		run_active_slot(slot);
 		if (results.curl_result == CURLE_OK) {
 			XML_Parser parser = XML_ParserCreate(NULL);
 			enum XML_Status result;
 			ctx.name = xcalloc(10, 1);
 			ctx.len = 0;
 			ctx.cdata = NULL;
 			ctx.userFunc = handle_lockprop_ctx;
 			ctx.userData = &lock_flags;
 			XML_SetUserData(parser, &ctx);
 			XML_SetElementHandler(parser, xml_start_tag,
 					      xml_end_tag);
 			result = XML_Parse(parser, in_buffer.buf,
 					   in_buffer.len, 1);
 			free(ctx.name);

 			if (result != XML_STATUS_OK) {
 				fprintf(stderr, "XML error: %s\n",
 					XML_ErrorString(
 						XML_GetErrorCode(parser)));
 				lock_flags = 0;
 			}
 			XML_ParserFree(parser);
 			if (!lock_flags)
 				error("no DAV locking support on %s",
 				      repo->url);

 		} else {
 			error("Cannot access URL %s, return code %d",
 			      repo->url, results.curl_result);
 			lock_flags = 0;
 		}
 	} else {
 		error("Unable to start PROPFIND request on %s", repo->url);
 	}

 	strbuf_release(&out_buffer.buf);
 	strbuf_release(&in_buffer);
 	curl_slist_free_all(dav_headers);

 	return lock_flags;
 }

 static struct object_list **add_one_object(struct object *obj, struct object_list **p)
 {
 	struct object_list *entry = xmalloc(sizeof(struct object_list));
 	entry->item = obj;
 	entry->next = *p;
 	*p = entry;
 	return &entry->next;
 }

 static struct object_list **process_blob(struct blob *blob,
 					 struct object_list **p)
 {
 	struct object *obj = &blob->object;

 	obj->flags |= LOCAL;

 	if (obj->flags & (UNINTERESTING | SEEN))
 		return p;

 	obj->flags |= SEEN;
 	return add_one_object(obj, p);
 }

 static struct object_list **process_tree(struct tree *tree,
 					 struct object_list **p)
 {
 	struct object *obj = &tree->object;
 	struct tree_desc desc;
 	struct name_entry entry;

 	obj->flags |= LOCAL;

 	if (obj->flags & (UNINTERESTING | SEEN))
 		return p;
 	if (parse_tree(tree) < 0)
 		die("bad tree object %s", oid_to_hex(&obj->oid));

 	obj->flags |= SEEN;
 	p = add_one_object(obj, p);

 	init_tree_desc(&desc, &tree->object.oid, tree->buffer, tree->size);

 	while (tree_entry(&desc, &entry))
 		switch (object_type(entry.mode)) {
 		case OBJ_TREE:
 			p = process_tree(lookup_tree(the_repository, &entry.oid),
 					 p);
 			break;
 		case OBJ_BLOB:
 			p = process_blob(lookup_blob(the_repository, &entry.oid),
 					 p);
 			break;
 		default:
 			/* Subproject commit - not in this repository */
 			break;
 		}

 	free_tree_buffer(tree);
 	return p;
 }

 static int get_delta(struct rev_info *revs, struct remote_lock *lock)
 {
 	int i;
 	struct commit *commit;
 	struct object_list **p = &objects;
 	int count = 0;

 	while ((commit = get_revision(revs)) != NULL) {
 		p = process_tree(repo_get_commit_tree(the_repository, commit),
 				 p);
 		commit->object.flags |= LOCAL;
 		if (!(commit->object.flags & UNINTERESTING))
 			count += add_send_request(&commit->object, lock);
 	}

 	for (i = 0; i < revs->pending.nr; i++) {
 		struct object_array_entry *entry = revs->pending.objects + i;
 		struct object *obj = entry->item;
 		const char *name = entry->name;

 		if (obj->flags & (UNINTERESTING | SEEN))
 			continue;
 		if (obj->type == OBJ_TAG) {
 			obj->flags |= SEEN;
 			p = add_one_object(obj, p);
 			continue;
 		}
 		if (obj->type == OBJ_TREE) {
 			p = process_tree((struct tree *)obj, p);
 			continue;
 		}
 		if (obj->type == OBJ_BLOB) {
 			p = process_blob((struct blob *)obj, p);
 			continue;
 		}
 		die("unknown pending object %s (%s)", oid_to_hex(&obj->oid), name);
 	}

 	while (objects) {
 		if (!(objects->item->flags & UNINTERESTING))
 			count += add_send_request(objects->item, lock);
 		objects = objects->next;
 	}

 	return count;
 }

 static int update_remote(const struct object_id *oid, struct remote_lock *lock)
 {
 	struct active_request_slot *slot;
 	struct slot_results results;
 	struct buffer out_buffer = { STRBUF_INIT, 0 };
 	struct curl_slist *dav_headers;

 	dav_headers = get_dav_token_headers(lock, DAV_HEADER_IF);

 	strbuf_addf(&out_buffer.buf, "%s\n", oid_to_hex(oid));

 	slot = get_active_slot();
 	slot->results = &results;
 	curl_setup_http(slot->curl, lock->url, DAV_PUT,
 			&out_buffer, fwrite_null);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);

 	if (start_active_slot(slot)) {
 		run_active_slot(slot);
 		strbuf_release(&out_buffer.buf);
 		if (results.curl_result != CURLE_OK) {
 			fprintf(stderr,
 				"PUT error: curl result=%d, HTTP code=%ld\n",
 				results.curl_result, results.http_code);
 			/* We should attempt recovery? */
 			return 0;
 		}
 	} else {
 		strbuf_release(&out_buffer.buf);
 		fprintf(stderr, "Unable to start PUT request\n");
 		return 0;
 	}

 	return 1;
 }

 static struct ref *remote_refs;

 static void one_remote_ref(const char *refname)
 {
 	struct ref *ref;
 	struct object *obj;

 	ref = alloc_ref(refname);

 	if (http_fetch_ref(repo->url, ref) != 0) {
 		fprintf(stderr,
 			"Unable to fetch ref %s from %s\n",
 			refname, repo->url);
 		free(ref);
 		return;
 	}

 	/*
 	 * Fetch a copy of the object if it doesn't exist locally - it
 	 * may be required for updating server info later.
 	 */
 	if (repo->can_update_info_refs && !repo_has_object_file(the_repository, &ref->old_oid)) {
 		obj = lookup_unknown_object(the_repository, &ref->old_oid);
 		fprintf(stderr,	"  fetch %s for %s\n",
 			oid_to_hex(&ref->old_oid), refname);
 		add_fetch_request(obj);
 	}

 	ref->next = remote_refs;
 	remote_refs = ref;
 }

 static void get_dav_remote_heads(void)
 {
 	remote_ls("refs/", (PROCESS_FILES | PROCESS_DIRS | RECURSIVE), process_ls_ref, NULL);
 }

 static void add_remote_info_ref(struct remote_ls_ctx *ls)
 {
 	struct strbuf *buf = (struct strbuf *)ls->userData;
 	struct object *o;
 	struct ref *ref;

 	ref = alloc_ref(ls->dentry_name);

 	if (http_fetch_ref(repo->url, ref) != 0) {
 		fprintf(stderr,
 			"Unable to fetch ref %s from %s\n",
 			ls->dentry_name, repo->url);
 		aborted = 1;
 		free(ref);
 		return;
 	}

 	o = parse_object(the_repository, &ref->old_oid);
 	if (!o) {
 		fprintf(stderr,
 			"Unable to parse object %s for remote ref %s\n",
 			oid_to_hex(&ref->old_oid), ls->dentry_name);
 		aborted = 1;
 		free(ref);
 		return;
 	}

 	strbuf_addf(buf, "%s\t%s\n",
 		    oid_to_hex(&ref->old_oid), ls->dentry_name);

 	if (o->type == OBJ_TAG) {
 		o = deref_tag(the_repository, o, ls->dentry_name, 0);
 		if (o)
 			strbuf_addf(buf, "%s\t%s^{}\n",
 				    oid_to_hex(&o->oid), ls->dentry_name);
 	}
 	free(ref);
 }

 static void update_remote_info_refs(struct remote_lock *lock)
 {
 	struct buffer buffer = { STRBUF_INIT, 0 };
 	struct active_request_slot *slot;
 	struct slot_results results;
 	struct curl_slist *dav_headers;

 	remote_ls("refs/", (PROCESS_FILES | RECURSIVE),
 		  add_remote_info_ref, &buffer.buf);
 	if (!aborted) {
 		dav_headers = get_dav_token_headers(lock, DAV_HEADER_IF);

 		slot = get_active_slot();
 		slot->results = &results;
 		curl_setup_http(slot->curl, lock->url, DAV_PUT,
 				&buffer, fwrite_null);
 		curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);

 		if (start_active_slot(slot)) {
 			run_active_slot(slot);
 			if (results.curl_result != CURLE_OK) {
 				fprintf(stderr,
 					"PUT error: curl result=%d, HTTP code=%ld\n",
 					results.curl_result, results.http_code);
 			}
 		}
 	}
 	strbuf_release(&buffer.buf);
 }

 static int remote_exists(const char *path)
 {
 	char *url = xstrfmt("%s%s", repo->url, path);
 	int ret;


 	switch (http_get_strbuf(url, NULL, NULL)) {
 	case HTTP_OK:
 		ret = 1;
 		break;
 	case HTTP_MISSING_TARGET:
 		ret = 0;
 		break;
 	case HTTP_ERROR:
 		error("unable to access '%s': %s", url, curl_errorstr);
 		/* fallthrough */
 	default:
 		ret = -1;
 	}
 	free(url);
 	return ret;
 }

 static void fetch_symref(const char *path, char **symref, struct object_id *oid)
 {
 	char *url = xstrfmt("%s%s", repo->url, path);
 	struct strbuf buffer = STRBUF_INIT;
 	const char *name;

 	if (http_get_strbuf(url, &buffer, NULL) != HTTP_OK)
 		die("Couldn't get %s for remote symref\n%s", url,
 		    curl_errorstr);
 	free(url);

 	FREE_AND_NULL(*symref);
 	oidclr(oid);

 	if (buffer.len == 0)
 		return;

 	/* Cut off trailing newline. */
 	strbuf_rtrim(&buffer);

 	/* If it's a symref, set the refname; otherwise try for a sha1 */
 	if (skip_prefix(buffer.buf, "ref: ", &name)) {
 		*symref = xmemdupz(name, buffer.len - (name - buffer.buf));
 	} else {
 		get_oid_hex(buffer.buf, oid);
 	}

 	strbuf_release(&buffer);
 }

 static int verify_merge_base(struct object_id *head_oid, struct ref *remote)
 {
 	struct commit *head = lookup_commit_or_die(head_oid, "HEAD");
 	struct commit *branch = lookup_commit_or_die(&remote->old_oid,
 						     remote->name);
 	int ret = repo_in_merge_bases(the_repository, branch, head);

 	if (ret < 0)
 		exit(128);
 	return ret;
 }

 static int delete_remote_branch(const char *pattern, int force)
 {
 	struct ref *refs = remote_refs;
 	struct ref *remote_ref = NULL;
 	struct object_id head_oid;
 	char *symref = NULL;
 	int match;
 	int patlen = strlen(pattern);
 	int i;
 	struct active_request_slot *slot;
 	struct slot_results results;
 	char *url;

 	/* Find the remote branch(es) matching the specified branch name */
 	for (match = 0; refs; refs = refs->next) {
 		char *name = refs->name;
 		int namelen = strlen(name);
 		if (namelen < patlen ||
 		    memcmp(name + namelen - patlen, pattern, patlen))
 			continue;
 		if (namelen != patlen && name[namelen - patlen - 1] != '/')
 			continue;
 		match++;
 		remote_ref = refs;
 	}
 	if (match == 0)
 		return error("No remote branch matches %s", pattern);
 	if (match != 1)
 		return error("More than one remote branch matches %s",
 			     pattern);

 	/*
 	 * Remote HEAD must be a symref (not exactly foolproof; a remote
 	 * symlink to a symref will look like a symref)
 	 */
 	fetch_symref("HEAD", &symref, &head_oid);
 	if (!symref)
 		return error("Remote HEAD is not a symref");

 	/* Remote branch must not be the remote HEAD */
 	for (i = 0; symref && i < MAXDEPTH; i++) {
 		if (!strcmp(remote_ref->name, symref))
 			return error("Remote branch %s is the current HEAD",
 				     remote_ref->name);
 		fetch_symref(symref, &symref, &head_oid);
 	}

 	/* Run extra sanity checks if delete is not forced */
 	if (!force) {
 		/* Remote HEAD must resolve to a known object */
 		if (symref)
 			return error("Remote HEAD symrefs too deep");
 		if (is_null_oid(&head_oid))
 			return error("Unable to resolve remote HEAD");
 		if (!repo_has_object_file(the_repository, &head_oid))
 			return error("Remote HEAD resolves to object %s\nwhich does not exist locally, perhaps you need to fetch?", oid_to_hex(&head_oid));

 		/* Remote branch must resolve to a known object */
 		if (is_null_oid(&remote_ref->old_oid))
 			return error("Unable to resolve remote branch %s",
 				     remote_ref->name);
 		if (!repo_has_object_file(the_repository, &remote_ref->old_oid))
 			return error("Remote branch %s resolves to object %s\nwhich does not exist locally, perhaps you need to fetch?", remote_ref->name, oid_to_hex(&remote_ref->old_oid));

 		/* Remote branch must be an ancestor of remote HEAD */
 		if (!verify_merge_base(&head_oid, remote_ref)) {
 			return error("The branch '%s' is not an ancestor "
 				     "of your current HEAD.\n"
 				     "If you are sure you want to delete it,"
 				     " run:\n\t'git http-push -D %s %s'",
 				     remote_ref->name, repo->url, pattern);
 		}
 	}

 	/* Send delete request */
 	fprintf(stderr, "Removing remote branch '%s'\n", remote_ref->name);
 	if (dry_run)
 		return 0;
 	url = xstrfmt("%s%s", repo->url, remote_ref->name);
 	slot = get_active_slot();
 	slot->results = &results;
 	curl_setup_http_get(slot->curl, url, DAV_DELETE);
 	if (start_active_slot(slot)) {
 		run_active_slot(slot);
 		free(url);
 		if (results.curl_result != CURLE_OK)
 			return error("DELETE request failed (%d/%ld)",
 				     results.curl_result, results.http_code);
 	} else {
 		free(url);
 		return error("Unable to start DELETE request");
 	}

 	return 0;
 }

 static void run_request_queue(void)
 {
 	is_running_queue = 1;
 	fill_active_slots();
 	add_fill_function(NULL, fill_active_slot);
 	do {
 		finish_all_active_slots();
 		fill_active_slots();
 	} while (request_queue_head && !aborted);

 	is_running_queue = 0;
 }

 int cmd_main(int argc, const char **argv)
 {
 	struct transfer_request *request;
 	struct transfer_request *next_request;
 	struct refspec rs = REFSPEC_INIT_PUSH;
 	struct remote_lock *ref_lock = NULL;
 	struct remote_lock *info_ref_lock = NULL;
 	int delete_branch = 0;
 	int force_delete = 0;
 	int objects_to_send;
 	int rc = 0;
 	int i;
 	int new_refs;
 	struct ref *ref, *local_refs;

 	CALLOC_ARRAY(repo, 1);

 	argv++;
 	for (i = 1; i < argc; i++, argv++) {
 		const char *arg = *argv;

 		if (*arg == '-') {
 			if (!strcmp(arg, "--all")) {
 				push_all = MATCH_REFS_ALL;
 				continue;
 			}
 			if (!strcmp(arg, "--force")) {
 				force_all = 1;
 				continue;
 			}
 			if (!strcmp(arg, "--dry-run")) {
 				dry_run = 1;
 				continue;
 			}
 			if (!strcmp(arg, "--helper-status")) {
 				helper_status = 1;
 				continue;
 			}
 			if (!strcmp(arg, "--verbose")) {
 				push_verbosely = 1;
 				http_is_verbose = 1;
 				continue;
 			}
 			if (!strcmp(arg, "-d")) {
 				delete_branch = 1;
 				continue;
 			}
 			if (!strcmp(arg, "-D")) {
 				delete_branch = 1;
 				force_delete = 1;
 				continue;
 			}
 			if (!strcmp(arg, "-h"))
 				usage(http_push_usage);
 		}
 		if (!repo->url) {
 			char *path = strstr(arg, "//");
 			str_end_url_with_slash(arg, &repo->url);
 			repo->path_len = strlen(repo->url);
 			if (path) {
 				repo->path = strchr(path+2, '/');
 				if (repo->path)
 					repo->path_len = strlen(repo->path);
 			}
 			continue;
 		}
 		refspec_appendn(&rs, argv, argc - i);
 		break;
 	}

 	if (!repo->url)
 		usage(http_push_usage);

 	if (delete_branch && rs.nr != 1)
 		die("You must specify only one branch name when deleting a remote branch");

 	setup_git_directory();

 	memset(remote_dir_exists, -1, 256);

 	http_init(NULL, repo->url, 1);

 	is_running_queue = 0;

 	/* Verify DAV compliance/lock support */
 	if (!locking_available()) {
 		rc = 1;
 		goto cleanup;
 	}

 	sigchain_push_common(remove_locks_on_signal);

 	/* Check whether the remote has server info files */
 	repo->can_update_info_refs = 0;
 	repo->has_info_refs = remote_exists("info/refs");
 	repo->has_info_packs = remote_exists("objects/info/packs");
 	if (repo->has_info_refs) {
 		info_ref_lock = lock_remote("info/refs", LOCK_TIME);
 		if (info_ref_lock)
 			repo->can_update_info_refs = 1;
 		else {
 			error("cannot lock existing info/refs");
 			rc = 1;
 			goto cleanup;
 		}
 	}
 	if (repo->has_info_packs)
 		fetch_indices();

 	/* Get a list of all local and remote heads to validate refspecs */
 	local_refs = get_local_heads();
 	fprintf(stderr, "Fetching remote heads...\n");
 	get_dav_remote_heads();
 	run_request_queue();

 	/* Remove a remote branch if -d or -D was specified */
 	if (delete_branch) {
 		const char *branch = rs.items[i].src;
 		if (delete_remote_branch(branch, force_delete) == -1) {
 			fprintf(stderr, "Unable to delete remote branch %s\n",
 				branch);
 			if (helper_status)
 				printf("error %s cannot remove\n", branch);
 		}
 		goto cleanup;
 	}

 	/* match them up */
 	if (match_push_refs(local_refs, &remote_refs, &rs, push_all)) {
 		rc = -1;
 		goto cleanup;
 	}
 	if (!remote_refs) {
 		fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
 		if (helper_status)
 			printf("error null no match\n");
 		rc = 0;
 		goto cleanup;
 	}

 	new_refs = 0;
 	for (ref = remote_refs; ref; ref = ref->next) {
 		struct rev_info revs;
 		struct strvec commit_argv = STRVEC_INIT;

 		if (!ref->peer_ref)
 			continue;

 		if (is_null_oid(&ref->peer_ref->new_oid)) {
 			if (delete_remote_branch(ref->name, 1) == -1) {
 				error("Could not remove %s", ref->name);
 				if (helper_status)
 					printf("error %s cannot remove\n", ref->name);
 				rc = -4;
 			}
 			else if (helper_status)
 				printf("ok %s\n", ref->name);
 			new_refs++;
 			continue;
 		}

 		if (oideq(&ref->old_oid, &ref->peer_ref->new_oid)) {
 			if (push_verbosely)
 				/* stable plumbing output; do not modify or localize */
 				fprintf(stderr, "'%s': up-to-date\n", ref->name);
 			if (helper_status)
 				printf("ok %s up to date\n", ref->name);
 			continue;
 		}

 		if (!force_all &&
 		    !is_null_oid(&ref->old_oid) &&
 		    !ref->force) {
 			if (!repo_has_object_file(the_repository, &ref->old_oid) ||
 			    !ref_newer(&ref->peer_ref->new_oid,
 				       &ref->old_oid)) {
 				/*
 				 * We do not have the remote ref, or
 				 * we know that the remote ref is not
 				 * an ancestor of what we are trying to
 				 * push.  Either way this can be losing
 				 * commits at the remote end and likely
 				 * we were not up to date to begin with.
 				 */
 				/* stable plumbing output; do not modify or localize */
 				error("remote '%s' is not an ancestor of\n"
 				      "local '%s'.\n"
 				      "Maybe you are not up-to-date and "
 				      "need to pull first?",
 				      ref->name,
 				      ref->peer_ref->name);
 				if (helper_status)
 					printf("error %s non-fast forward\n", ref->name);
 				rc = -2;
 				continue;
 			}
 		}
 		oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
 		new_refs++;

 		fprintf(stderr, "updating '%s'", ref->name);
 		if (strcmp(ref->name, ref->peer_ref->name))
 			fprintf(stderr, " using '%s'", ref->peer_ref->name);
 		fprintf(stderr, "\n  from %s\n  to   %s\n",
 			oid_to_hex(&ref->old_oid), oid_to_hex(&ref->new_oid));
 		if (dry_run) {
 			if (helper_status)
 				printf("ok %s\n", ref->name);
 			continue;
 		}

 		/* Lock remote branch ref */
 		ref_lock = lock_remote(ref->name, LOCK_TIME);
 		if (!ref_lock) {
 			fprintf(stderr, "Unable to lock remote branch %s\n",
 				ref->name);
 			if (helper_status)
 				printf("error %s lock error\n", ref->name);
 			rc = 1;
 			continue;
 		}

 		/* Set up revision info for this refspec */
 		strvec_push(&commit_argv, ""); /* ignored */
 		strvec_push(&commit_argv, "--objects");
 		strvec_push(&commit_argv, oid_to_hex(&ref->new_oid));
 		if (!push_all && !is_null_oid(&ref->old_oid))
 			strvec_pushf(&commit_argv, "^%s",
 				     oid_to_hex(&ref->old_oid));
 		repo_init_revisions(the_repository, &revs, setup_git_directory());
 		setup_revisions(commit_argv.nr, commit_argv.v, &revs, NULL);
 		revs.edge_hint = 0; /* just in case */

 		/* Generate a list of objects that need to be pushed */
 		pushing = 0;
 		if (prepare_revision_walk(&revs))
 			die("revision walk setup failed");
 		mark_edges_uninteresting(&revs, NULL, 0);
 		objects_to_send = get_delta(&revs, ref_lock);
 		finish_all_active_slots();

 		/* Push missing objects to remote, this would be a
 		   convenient time to pack them first if appropriate. */
 		pushing = 1;
 		if (objects_to_send)
 			fprintf(stderr, "    sending %d objects\n",
 				objects_to_send);

 		run_request_queue();

 		/* Update the remote branch if all went well */
 		if (aborted || !update_remote(&ref->new_oid, ref_lock))
 			rc = 1;

 		if (!rc)
 			fprintf(stderr, "    done\n");
 		if (helper_status)
 			printf("%s %s\n", !rc ? "ok" : "error", ref->name);
 		unlock_remote(ref_lock);
 		check_locks();
 		strvec_clear(&commit_argv);
 		release_revisions(&revs);
 	}

 	/* Update remote server info if appropriate */
 	if (repo->has_info_refs && new_refs) {
 		if (info_ref_lock && repo->can_update_info_refs) {
 			fprintf(stderr, "Updating remote server info\n");
 			if (!dry_run)
 				update_remote_info_refs(info_ref_lock);
 		} else {
 			fprintf(stderr, "Unable to update server info\n");
 		}
 	}

  cleanup:
 	if (info_ref_lock)
 		unlock_remote(info_ref_lock);
 	free(repo);

 	http_cleanup();

 	request = request_queue_head;
 	while (request != NULL) {
 		next_request = request->next;
 		release_request(request);
 		request = next_request;
 	}

 	return rc;
 }