Merge branch 'rc/http-push'

* rc/http-push: (22 commits)
  http*: add helper methods for fetching objects (loose)
  http*: add helper methods for fetching packs
  http: use new http API in fetch_index()
  http*: add http_get_info_packs
  http-push.c::fetch_symref(): use the new http API
  http-push.c::remote_exists(): use the new http API
  http.c::http_fetch_ref(): use the new http API
  transport.c::get_refs_via_curl(): use the new http API
  http.c: new functions for the http API
  http: create function end_url_with_slash
  http*: move common variables and macros to http.[ch]
  transport.c::get_refs_via_curl(): do not leak refs_url
  Don't expect verify_pack() callers to set pack_size
  http-push: do not SEGV after fetching a bad pack idx file
  http*: copy string returned by sha1_to_hex
  http-walker: verify remote packs
  http-push, http-walker: style fixes
  t5550-http-fetch: test fetching of packed objects
  http-push: fix missing "#ifdef USE_CURL_MULTI" around "is_running_queue"
  http-push: send out fetch requests on queue
  ...

8 files changed, 904 insertions, 993 deletions

diff --git a/http-push.c b/http-push.c
index c25c4f917..e4ea395e0 100644
--- a/http-push.c
+++ b/http-push.c
@@ -1,6 +1,5 @@
 #include "cache.h"
 #include "commit.h"
-#include "pack.h"
 #include "tag.h"
 #include "blob.h"
 #include "http.h"
@@ -27,7 +26,6 @@ enum XML_Status {
 #endif
 
 #define PREV_BUF_SIZE 4096
-#define RANGE_HEADER_SIZE 30
 
 /* DAV methods */
 #define DAV_LOCK "LOCK"
@@ -76,8 +74,6 @@ static int pushing;
 static int aborted;
 static signed char remote_dir_exists[256];
 
-static struct curl_slist *no_pragma_header;
-
 static int push_verbosely;
 static int push_all = MATCH_REFS_NONE;
 static int force_all;
@@ -119,19 +115,10 @@ struct transfer_request
 	struct remote_lock *lock;
 	struct curl_slist *headers;
 	struct buffer buffer;
-	char filename[PATH_MAX];
-	char tmpfile[PATH_MAX];
-	int local_fileno;
-	FILE *local_stream;
 	enum transfer_state state;
 	CURLcode curl_result;
 	char errorstr[CURL_ERROR_SIZE];
 	long http_code;
-	unsigned char real_sha1[20];
-	git_SHA_CTX c;
-	z_stream stream;
-	int zret;
-	int rename;
 	void *userData;
 	struct active_request_slot *slot;
 	struct transfer_request *next;
@@ -237,15 +224,6 @@ static struct curl_slist *get_dav_token_headers(struct remote_lock *lock, enum d
 	return dav_headers;
 }
 
-static void append_remote_object_url(struct strbuf *buf, const char *url,
-				     const char *hex,
-				     int only_two_digit_prefix)
-{
-	strbuf_addf(buf, "%sobjects/%.*s/", url, 2, hex);
-	if (!only_two_digit_prefix)
-		strbuf_addf(buf, "%s", hex+2);
-}
-
 static void finish_request(struct transfer_request *request);
 static void release_request(struct transfer_request *request);
 
@@ -259,163 +237,29 @@ static void process_response(void *callback_data)
 
 #ifdef USE_CURL_MULTI
 
-static char *get_remote_object_url(const char *url, const char *hex,
-				   int only_two_digit_prefix)
-{
-	struct strbuf buf = STRBUF_INIT;
-	append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
-	return strbuf_detach(&buf, NULL);
-}
-
-static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
-			       void *data)
-{
-	unsigned char expn[4096];
-	size_t size = eltsize * nmemb;
-	int posn = 0;
-	struct transfer_request *request = (struct transfer_request *)data;
-	do {
-		ssize_t retval = xwrite(request->local_fileno,
-				       (char *) ptr + posn, size - posn);
-		if (retval < 0)
-			return posn;
-		posn += retval;
-	} while (posn < size);
-
-	request->stream.avail_in = size;
-	request->stream.next_in = ptr;
-	do {
-		request->stream.next_out = expn;
-		request->stream.avail_out = sizeof(expn);
-		request->zret = git_inflate(&request->stream, Z_SYNC_FLUSH);
-		git_SHA1_Update(&request->c, expn,
-			    sizeof(expn) - request->stream.avail_out);
-	} while (request->stream.avail_in && request->zret == Z_OK);
-	data_received++;
-	return size;
-}
-
 static void start_fetch_loose(struct transfer_request *request)
 {
-	char *hex = sha1_to_hex(request->obj->sha1);
-	char *filename;
-	char prevfile[PATH_MAX];
-	char *url;
-	int prevlocal;
-	unsigned char prev_buf[PREV_BUF_SIZE];
-	ssize_t prev_read = 0;
-	long prev_posn = 0;
-	char range[RANGE_HEADER_SIZE];
-	struct curl_slist *range_header = NULL;
 	struct active_request_slot *slot;
+	struct http_object_request *obj_req;
 
-	filename = sha1_file_name(request->obj->sha1);
-	snprintf(request->filename, sizeof(request->filename), "%s", filename);
-	snprintf(request->tmpfile, sizeof(request->tmpfile),
-		 "%s.temp", filename);
-
-	snprintf(prevfile, sizeof(prevfile), "%s.prev", request->filename);
-	unlink_or_warn(prevfile);
-	rename(request->tmpfile, prevfile);
-	unlink_or_warn(request->tmpfile);
-
-	if (request->local_fileno != -1)
-		error("fd leakage in start: %d", request->local_fileno);
-	request->local_fileno = open(request->tmpfile,
-				     O_WRONLY | O_CREAT | O_EXCL, 0666);
-	/* This could have failed due to the "lazy directory creation";
-	 * try to mkdir the last path component.
-	 */
-	if (request->local_fileno < 0 && errno == ENOENT) {
-		char *dir = strrchr(request->tmpfile, '/');
-		if (dir) {
-			*dir = 0;
-			mkdir(request->tmpfile, 0777);
-			*dir = '/';
-		}
-		request->local_fileno = open(request->tmpfile,
-					     O_WRONLY | O_CREAT | O_EXCL, 0666);
-	}
-
-	if (request->local_fileno < 0) {
+	obj_req = new_http_object_request(repo->url, request->obj->sha1);
+	if (obj_req == NULL) {
 		request->state = ABORTED;
-		error("Couldn't create temporary file %s for %s: %s",
-		      request->tmpfile, request->filename, strerror(errno));
 		return;
 	}
 
-	memset(&request->stream, 0, sizeof(request->stream));
-
-	git_inflate_init(&request->stream);
-
-	git_SHA1_Init(&request->c);
-
-	url = get_remote_object_url(repo->url, hex, 0);
-	request->url = xstrdup(url);
-
-	/* If a previous temp file is present, process what was already
-	   fetched. */
-	prevlocal = open(prevfile, O_RDONLY);
-	if (prevlocal != -1) {
-		do {
-			prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
-			if (prev_read>0) {
-				if (fwrite_sha1_file(prev_buf,
-						     1,
-						     prev_read,
-						     request) == prev_read) {
-					prev_posn += prev_read;
-				} else {
-					prev_read = -1;
-				}
-			}
-		} while (prev_read > 0);
-		close(prevlocal);
-	}
-	unlink_or_warn(prevfile);
-
-	/* Reset inflate/SHA1 if there was an error reading the previous temp
-	   file; also rewind to the beginning of the local file. */
-	if (prev_read == -1) {
-		memset(&request->stream, 0, sizeof(request->stream));
-		git_inflate_init(&request->stream);
-		git_SHA1_Init(&request->c);
-		if (prev_posn>0) {
-			prev_posn = 0;
-			lseek(request->local_fileno, 0, SEEK_SET);
-			ftruncate(request->local_fileno, 0);
-		}
-	}
-
-	slot = get_active_slot();
+	slot = obj_req->slot;
 	slot->callback_func = process_response;
 	slot->callback_data = request;
 	request->slot = slot;
-
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, request);
-	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
-	curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, request->errorstr);
-	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
-
-	/* If we have successfully processed data from a previous fetch
-	   attempt, only fetch the data we don't already have. */
-	if (prev_posn>0) {
-		if (push_verbosely)
-			fprintf(stderr,
-				"Resuming fetch of object %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);
-	}
+	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);
 	}
 }
@@ -449,16 +293,10 @@ static void start_mkcol(struct transfer_request *request)
 
 static void start_fetch_packed(struct transfer_request *request)
 {
-	char *url;
 	struct packed_git *target;
-	FILE *packfile;
-	char *filename;
-	long prev_posn = 0;
-	char range[RANGE_HEADER_SIZE];
-	struct curl_slist *range_header = NULL;
 
 	struct transfer_request *check_request = request_queue_head;
-	struct active_request_slot *slot;
+	struct http_pack_request *preq;
 
 	target = find_sha1_pack(request->obj->sha1, repo->packs);
 	if (!target) {
@@ -471,66 +309,35 @@ static void start_fetch_packed(struct transfer_request *request)
 	fprintf(stderr,	"Fetching pack %s\n", sha1_to_hex(target->sha1));
 	fprintf(stderr, " which contains %s\n", sha1_to_hex(request->obj->sha1));
 
-	filename = sha1_pack_name(target->sha1);
-	snprintf(request->filename, sizeof(request->filename), "%s", filename);
-	snprintf(request->tmpfile, sizeof(request->tmpfile),
-		 "%s.temp", filename);
-
-	url = xmalloc(strlen(repo->url) + 64);
-	sprintf(url, "%sobjects/pack/pack-%s.pack",
-		repo->url, sha1_to_hex(target->sha1));
+	preq = new_http_pack_request(target, repo->url);
+	if (preq == NULL) {
+		release_http_pack_request(preq);
+		repo->can_update_info_refs = 0;
+		return;
+	}
+	preq->lst = &repo->packs;
 
 	/* 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, url)) {
-			free(url);
+		    !strcmp(check_request->url, preq->url)) {
+			release_http_pack_request(preq);
 			release_request(request);
 			return;
 		}
 		check_request = check_request->next;
 	}
 
-	packfile = fopen(request->tmpfile, "a");
-	if (!packfile) {
-		fprintf(stderr, "Unable to open local file %s for pack",
-			request->tmpfile);
-		repo->can_update_info_refs = 0;
-		free(url);
-		return;
-	}
-
-	slot = get_active_slot();
-	slot->callback_func = process_response;
-	slot->callback_data = request;
-	request->slot = slot;
-	request->local_stream = packfile;
-	request->userData = target;
-
-	request->url = url;
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
-	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 = packfile;
-
-	/* If there is data present from a previous transfer attempt,
-	   resume where it left off */
-	prev_posn = ftell(packfile);
-	if (prev_posn>0) {
-		if (push_verbosely)
-			fprintf(stderr,
-				"Resuming fetch of pack %s at byte %ld\n",
-				sha1_to_hex(target->sha1), 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);
-	}
+	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(slot)) {
+	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);
 	}
@@ -711,24 +518,17 @@ static void release_request(struct transfer_request *request)
 			entry->next = entry->next->next;
 	}
 
-	if (request->local_fileno != -1)
-		close(request->local_fileno);
-	if (request->local_stream)
-		fclose(request->local_stream);
 	free(request->url);
 	free(request);
 }
 
 static void finish_request(struct transfer_request *request)
 {
-	struct stat st;
-	struct packed_git *target;
-	struct packed_git **lst;
-	struct active_request_slot *slot;
+	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;
-	slot = request->slot;
 	request->slot = NULL;
 
 	/* Keep locks active */
@@ -780,77 +580,46 @@ static void finish_request(struct transfer_request *request)
 			aborted = 1;
 		}
 	} else if (request->state == RUN_FETCH_LOOSE) {
-		close(request->local_fileno); request->local_fileno = -1;
+		obj_req = (struct http_object_request *)request->userData;
 
-		if (request->curl_result != CURLE_OK &&
-		    request->http_code != 416) {
-			if (stat(request->tmpfile, &st) == 0) {
-				if (st.st_size == 0)
-					unlink_or_warn(request->tmpfile);
-			}
-		} else {
-			if (request->http_code == 416)
-				warning("requested range invalid; we may already have all the data.");
-
-			git_inflate_end(&request->stream);
-			git_SHA1_Final(request->real_sha1, &request->c);
-			if (request->zret != Z_STREAM_END) {
-				unlink_or_warn(request->tmpfile);
-			} else if (hashcmp(request->obj->sha1, request->real_sha1)) {
-				unlink_or_warn(request->tmpfile);
-			} else {
-				request->rename =
-					move_temp_to_file(
-						request->tmpfile,
-						request->filename);
-				if (request->rename == 0) {
-					request->obj->flags |= (LOCAL | REMOTE);
-				}
-			}
-		}
+		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)
+		if (request->obj->flags & LOCAL) {
+			release_http_object_request(obj_req);
 			release_request(request);
-		else
+		} 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);
-			repo->can_update_info_refs = 0;
 		} else {
-			off_t pack_size = ftell(request->local_stream);
-
-			fclose(request->local_stream);
-			request->local_stream = NULL;
-			slot->local = NULL;
-			if (!move_temp_to_file(request->tmpfile,
-					       request->filename)) {
-				target = (struct packed_git *)request->userData;
-				target->pack_size = pack_size;
-				lst = &repo->packs;
-				while (*lst != target)
-					lst = &((*lst)->next);
-				*lst = (*lst)->next;
-
-				if (!verify_pack(target))
-					install_packed_git(target);
-				else
-					repo->can_update_info_refs = 0;
+			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;
 		release_request(request);
 	}
 }
 
 #ifdef USE_CURL_MULTI
+static int is_running_queue;
 static int fill_active_slot(void *unused)
 {
 	struct transfer_request *request;
 
-	if (aborted)
+	if (aborted || !is_running_queue)
 		return 0;
 
 	for (request = request_queue_head; request; request = request->next) {
@@ -893,8 +662,6 @@ static void add_fetch_request(struct object *obj)
 	request->url = NULL;
 	request->lock = NULL;
 	request->headers = NULL;
-	request->local_fileno = -1;
-	request->local_stream = NULL;
 	request->state = NEED_FETCH;
 	request->next = request_queue_head;
 	request_queue_head = request;
@@ -933,8 +700,6 @@ static int add_send_request(struct object *obj, struct remote_lock *lock)
 	request->url = NULL;
 	request->lock = lock;
 	request->headers = NULL;
-	request->local_fileno = -1;
-	request->local_stream = NULL;
 	request->state = NEED_PUSH;
 	request->next = request_queue_head;
 	request_queue_head = request;
@@ -947,179 +712,23 @@ static int add_send_request(struct object *obj, struct remote_lock *lock)
 	return 1;
 }
 
-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;
-	struct slot_results results;
-
-	/* Don't use the index if the pack isn't there */
-	url = xmalloc(strlen(repo->url) + 64);
-	sprintf(url, "%sobjects/pack/pack-%s.pack", repo->url, hex);
-	slot = get_active_slot();
-	slot->results = &results;
-	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 (results.curl_result != CURLE_OK) {
-			free(url);
-			return error("Unable to verify pack %s is available",
-				     hex);
-		}
-	} else {
-		free(url);
-		return error("Unable to start request");
-	}
-
-	if (has_pack_index(sha1)) {
-		free(url);
-		return 0;
-	}
-
-	if (push_verbosely)
-		fprintf(stderr, "Getting index for pack %s\n", hex);
-
-	sprintf(url, "%sobjects/pack/pack-%s.idx", repo->url, hex);
-
-	filename = sha1_pack_index_name(sha1);
-	snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
-	indexfile = fopen(tmpfile, "a");
-	if (!indexfile) {
-		free(url);
-		return error("Unable to open local file %s for pack index",
-			     tmpfile);
-	}
-
-	slot = get_active_slot();
-	slot->results = &results;
-	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 (results.curl_result != CURLE_OK) {
-			free(url);
-			fclose(indexfile);
-			slot->local = NULL;
-			return error("Unable to get pack index %s\n%s", url,
-				     curl_errorstr);
-		}
-	} else {
-		free(url);
-		fclose(indexfile);
-		slot->local = NULL;
-		return error("Unable to start request");
-	}
-
-	free(url);
-	fclose(indexfile);
-	slot->local = NULL;
-
-	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 = repo->packs;
-	repo->packs = new_pack;
-	return 0;
-}
-
 static int fetch_indices(void)
 {
-	unsigned char sha1[20];
-	char *url;
-	struct strbuf buffer = STRBUF_INIT;
-	char *data;
-	int i = 0;
-
-	struct active_request_slot *slot;
-	struct slot_results results;
+	int ret;
 
 	if (push_verbosely)
 		fprintf(stderr, "Getting pack list\n");
 
-	url = xmalloc(strlen(repo->url) + 20);
-	sprintf(url, "%sobjects/info/packs", repo->url);
-
-	slot = get_active_slot();
-	slot->results = &results;
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-	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 (results.curl_result != CURLE_OK) {
-			strbuf_release(&buffer);
-			free(url);
-			if (results.http_code == 404)
-				return 0;
-			else
-				return error("%s", curl_errorstr);
-		}
-	} else {
-		strbuf_release(&buffer);
-		free(url);
-		return error("Unable to start request");
-	}
-	free(url);
-
-	data = buffer.buf;
-	while (i < buffer.len) {
-		switch (data[i]) {
-		case 'P':
-			i++;
-			if (i + 52 < buffer.len &&
-			    !prefixcmp(data + i, " pack-") &&
-			    !prefixcmp(data + i + 46, ".pack\n")) {
-				get_sha1_hex(data + i + 6, sha1);
-				setup_index(sha1);
-				i += 51;
-				break;
-			}
-		default:
-			while (data[i] != '\n')
-				i++;
-		}
-		i++;
+	switch (http_get_info_packs(repo->url, &repo->packs)) {
+	case HTTP_OK:
+	case HTTP_MISSING_TARGET:
+		ret = 0;
+		break;
+	default:
+		ret = -1;
 	}
 
-	strbuf_release(&buffer);
-	return 0;
+	return ret;
 }
 
 static void one_remote_object(const char *hex)
@@ -1982,29 +1591,22 @@ static void update_remote_info_refs(struct remote_lock *lock)
 static int remote_exists(const char *path)
 {
 	char *url = xmalloc(strlen(repo->url) + strlen(path) + 1);
-	struct active_request_slot *slot;
-	struct slot_results results;
-	int ret = -1;
+	int ret;
 
 	sprintf(url, "%s%s", repo->url, path);
 
-	slot = get_active_slot();
-	slot->results = &results;
-	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 (results.http_code == 404)
-			ret = 0;
-		else if (results.curl_result == CURLE_OK)
-			ret = 1;
-		else
-			fprintf(stderr, "HEAD HTTP error %ld\n", results.http_code);
-	} else {
-		fprintf(stderr, "Unable to start HEAD request\n");
+	switch (http_get_strbuf(url, NULL, 0)) {
+	case HTTP_OK:
+		ret = 1;
+		break;
+	case HTTP_MISSING_TARGET:
+		ret = 0;
+		break;
+	case HTTP_ERROR:
+		http_error(url, HTTP_ERROR);
+	default:
+		ret = -1;
 	}
-
 	free(url);
 	return ret;
 }
@@ -2013,27 +1615,13 @@ static void fetch_symref(const char *path, char **symref, unsigned char *sha1)
 {
 	char *url;
 	struct strbuf buffer = STRBUF_INIT;
-	struct active_request_slot *slot;
-	struct slot_results results;
 
 	url = xmalloc(strlen(repo->url) + strlen(path) + 1);
 	sprintf(url, "%s%s", repo->url, path);
 
-	slot = get_active_slot();
-	slot->results = &results;
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-	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 (results.curl_result != CURLE_OK) {
-			die("Couldn't get %s for remote symref\n%s",
-			    url, curl_errorstr);
-		}
-	} else {
-		die("Unable to start remote symref request");
-	}
+	if (http_get_strbuf(url, &buffer, 0) != HTTP_OK)
+		die("Couldn't get %s for remote symref\n%s", url,
+		    curl_errorstr);
 	free(url);
 
 	free(*symref);
@@ -2162,6 +1750,25 @@ static int delete_remote_branch(char *pattern, int force)
 	return 0;
 }
 
+void run_request_queue(void)
+{
+#ifdef USE_CURL_MULTI
+	is_running_queue = 1;
+	fill_active_slots();
+	add_fill_function(NULL, fill_active_slot);
+#endif
+	do {
+		finish_all_active_slots();
+#ifdef USE_CURL_MULTI
+		fill_active_slots();
+#endif
+	} while (request_queue_head && !aborted);
+
+#ifdef USE_CURL_MULTI
+	is_running_queue = 0;
+#endif
+}
+
 int main(int argc, char **argv)
 {
 	struct transfer_request *request;
@@ -2206,6 +1813,7 @@ int main(int argc, char **argv)
 			}
 			if (!strcmp(arg, "--verbose")) {
 				push_verbosely = 1;
+				http_is_verbose = 1;
 				continue;
 			}
 			if (!strcmp(arg, "-d")) {
@@ -2255,8 +1863,6 @@ int main(int argc, char **argv)
 	remote->url[remote->url_nr++] = repo->url;
 	http_init(remote);
 
-	no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
-
 	if (repo->url && repo->url[strlen(repo->url)-1] != '/') {
 		rewritten_url = xmalloc(strlen(repo->url)+2);
 		strcpy(rewritten_url, repo->url);
@@ -2266,6 +1872,10 @@ int main(int argc, char **argv)
 		repo->url = rewritten_url;
 	}
 
+#ifdef USE_CURL_MULTI
+	is_running_queue = 0;
+#endif
+
 	/* Verify DAV compliance/lock support */
 	if (!locking_available()) {
 		rc = 1;
@@ -2295,6 +1905,7 @@ int main(int argc, char **argv)
 	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) {
@@ -2423,16 +2034,8 @@ int main(int argc, char **argv)
 		if (objects_to_send)
 			fprintf(stderr, "    sending %d objects\n",
 				objects_to_send);
-#ifdef USE_CURL_MULTI
-		fill_active_slots();
-		add_fill_function(NULL, fill_active_slot);
-#endif
-		do {
-			finish_all_active_slots();
-#ifdef USE_CURL_MULTI
-			fill_active_slots();
-#endif
-		} while (request_queue_head && !aborted);
+
+		run_request_queue();
 
 		/* Update the remote branch if all went well */
 		if (aborted || !update_remote(ref->new_sha1, ref_lock))
@@ -2461,8 +2064,6 @@ int main(int argc, char **argv)
 		unlock_remote(info_ref_lock);
 	free(repo);
 
-	curl_slist_free_all(no_pragma_header);
-
 	http_cleanup();
 
 	request = request_queue_head;
diff --git a/http-walker.c b/http-walker.c
index 937785192..700bc1311 100644
--- a/http-walker.c
+++ b/http-walker.c
@@ -1,12 +1,8 @@
 #include "cache.h"
 #include "commit.h"
-#include "pack.h"
 #include "walker.h"
 #include "http.h"
 
-#define PREV_BUF_SIZE 4096
-#define RANGE_HEADER_SIZE 30
-
 struct alt_base
 {
 	char *base;
@@ -27,20 +23,8 @@ struct object_request
 	struct walker *walker;
 	unsigned char sha1[20];
 	struct alt_base *repo;
-	char *url;
-	char filename[PATH_MAX];
-	char tmpfile[PATH_MAX];
-	int local;
 	enum object_request_state state;
-	CURLcode curl_result;
-	char errorstr[CURL_ERROR_SIZE];
-	long http_code;
-	unsigned char real_sha1[20];
-	git_SHA_CTX c;
-	z_stream stream;
-	int zret;
-	int rename;
-	struct active_request_slot *slot;
+	struct http_object_request *req;
 	struct object_request *next;
 };
 
@@ -57,39 +41,10 @@ struct walker_data {
 	const char *url;
 	int got_alternates;
 	struct alt_base *alt;
-	struct curl_slist *no_pragma_header;
 };
 
 static struct object_request *object_queue_head;
 
-static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
-			       void *data)
-{
-	unsigned char expn[4096];
-	size_t size = eltsize * nmemb;
-	int posn = 0;
-	struct object_request *obj_req = (struct object_request *)data;
-	do {
-		ssize_t retval = xwrite(obj_req->local,
-				       (char *) ptr + posn, size - posn);
-		if (retval < 0)
-			return posn;
-		posn += retval;
-	} while (posn < size);
-
-	obj_req->stream.avail_in = size;
-	obj_req->stream.next_in = ptr;
-	do {
-		obj_req->stream.next_out = expn;
-		obj_req->stream.avail_out = sizeof(expn);
-		obj_req->zret = git_inflate(&obj_req->stream, Z_SYNC_FLUSH);
-		git_SHA1_Update(&obj_req->c, expn,
-			    sizeof(expn) - obj_req->stream.avail_out);
-	} while (obj_req->stream.avail_in && obj_req->zret == Z_OK);
-	data_received++;
-	return size;
-}
-
 static void fetch_alternates(struct walker *walker, const char *base);
 
 static void process_object_response(void *callback_data);
@@ -97,165 +52,35 @@ static void process_object_response(void *callback_data);
 static void start_object_request(struct walker *walker,
 				 struct object_request *obj_req)
 {
-	char *hex = sha1_to_hex(obj_req->sha1);
-	char prevfile[PATH_MAX];
-	char *url;
-	char *posn;
-	int prevlocal;
-	unsigned char prev_buf[PREV_BUF_SIZE];
-	ssize_t prev_read = 0;
-	long prev_posn = 0;
-	char range[RANGE_HEADER_SIZE];
-	struct curl_slist *range_header = NULL;
 	struct active_request_slot *slot;
-	struct walker_data *data = walker->data;
+	struct http_object_request *req;
 
-	snprintf(prevfile, sizeof(prevfile), "%s.prev", obj_req->filename);
-	unlink_or_warn(prevfile);
-	rename(obj_req->tmpfile, prevfile);
-	unlink_or_warn(obj_req->tmpfile);
-
-	if (obj_req->local != -1)
-		error("fd leakage in start: %d", obj_req->local);
-	obj_req->local = open(obj_req->tmpfile,
-			      O_WRONLY | O_CREAT | O_EXCL, 0666);
-	/* This could have failed due to the "lazy directory creation";
-	 * try to mkdir the last path component.
-	 */
-	if (obj_req->local < 0 && errno == ENOENT) {
-		char *dir = strrchr(obj_req->tmpfile, '/');
-		if (dir) {
-			*dir = 0;
-			mkdir(obj_req->tmpfile, 0777);
-			*dir = '/';
-		}
-		obj_req->local = open(obj_req->tmpfile,
-				      O_WRONLY | O_CREAT | O_EXCL, 0666);
-	}
-
-	if (obj_req->local < 0) {
+	req = new_http_object_request(obj_req->repo->base, obj_req->sha1);
+	if (req == NULL) {
 		obj_req->state = ABORTED;
-		error("Couldn't create temporary file %s for %s: %s",
-		      obj_req->tmpfile, obj_req->filename, strerror(errno));
 		return;
 	}
+	obj_req->req = req;
 
-	memset(&obj_req->stream, 0, sizeof(obj_req->stream));
-
-	git_inflate_init(&obj_req->stream);
-
-	git_SHA1_Init(&obj_req->c);
-
-	url = xmalloc(strlen(obj_req->repo->base) + 51);
-	obj_req->url = xmalloc(strlen(obj_req->repo->base) + 51);
-	strcpy(url, obj_req->repo->base);
-	posn = url + strlen(obj_req->repo->base);
-	strcpy(posn, "/objects/");
-	posn += 9;
-	memcpy(posn, hex, 2);
-	posn += 2;
-	*(posn++) = '/';
-	strcpy(posn, hex + 2);
-	strcpy(obj_req->url, url);
-
-	/* If a previous temp file is present, process what was already
-	   fetched. */
-	prevlocal = open(prevfile, O_RDONLY);
-	if (prevlocal != -1) {
-		do {
-			prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
-			if (prev_read>0) {
-				if (fwrite_sha1_file(prev_buf,
-						     1,
-						     prev_read,
-						     obj_req) == prev_read) {
-					prev_posn += prev_read;
-				} else {
-					prev_read = -1;
-				}
-			}
-		} while (prev_read > 0);
-		close(prevlocal);
-	}
-	unlink_or_warn(prevfile);
-
-	/* Reset inflate/SHA1 if there was an error reading the previous temp
-	   file; also rewind to the beginning of the local file. */
-	if (prev_read == -1) {
-		memset(&obj_req->stream, 0, sizeof(obj_req->stream));
-		git_inflate_init(&obj_req->stream);
-		git_SHA1_Init(&obj_req->c);
-		if (prev_posn>0) {
-			prev_posn = 0;
-			lseek(obj_req->local, 0, SEEK_SET);
-			ftruncate(obj_req->local, 0);
-		}
-	}
-
-	slot = get_active_slot();
+	slot = req->slot;
 	slot->callback_func = process_object_response;
 	slot->callback_data = obj_req;
-	obj_req->slot = slot;
-
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, obj_req);
-	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
-	curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, obj_req->errorstr);
-	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, data->no_pragma_header);
-
-	/* If we have successfully processed data from a previous fetch
-	   attempt, only fetch the data we don't already have. */
-	if (prev_posn>0) {
-		if (walker->get_verbosely)
-			fprintf(stderr,
-				"Resuming fetch of object %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);
-	}
 
 	/* Try to get the request started, abort the request on error */
 	obj_req->state = ACTIVE;
 	if (!start_active_slot(slot)) {
 		obj_req->state = ABORTED;
-		obj_req->slot = NULL;
-		close(obj_req->local); obj_req->local = -1;
-		free(obj_req->url);
+		release_http_object_request(req);
 		return;
 	}
 }
 
 static void finish_object_request(struct object_request *obj_req)
 {
-	struct stat st;
-
-	close(obj_req->local); obj_req->local = -1;
-
-	if (obj_req->http_code == 416) {
-		fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
-	} else if (obj_req->curl_result != CURLE_OK) {
-		if (stat(obj_req->tmpfile, &st) == 0)
-			if (st.st_size == 0)
-				unlink_or_warn(obj_req->tmpfile);
-		return;
-	}
-
-	git_inflate_end(&obj_req->stream);
-	git_SHA1_Final(obj_req->real_sha1, &obj_req->c);
-	if (obj_req->zret != Z_STREAM_END) {
-		unlink_or_warn(obj_req->tmpfile);
+	if (finish_http_object_request(obj_req->req))
 		return;
-	}
-	if (hashcmp(obj_req->sha1, obj_req->real_sha1)) {
-		unlink_or_warn(obj_req->tmpfile);
-		return;
-	}
-	obj_req->rename =
-		move_temp_to_file(obj_req->tmpfile, obj_req->filename);
 
-	if (obj_req->rename == 0)
+	if (obj_req->req->rename == 0)
 		walker_say(obj_req->walker, "got %s\n", sha1_to_hex(obj_req->sha1));
 }
 
@@ -267,19 +92,16 @@ static void process_object_response(void *callback_data)
 	struct walker_data *data = walker->data;
 	struct alt_base *alt = data->alt;
 
-	obj_req->curl_result = obj_req->slot->curl_result;
-	obj_req->http_code = obj_req->slot->http_code;
-	obj_req->slot = NULL;
+	process_http_object_request(obj_req->req);
 	obj_req->state = COMPLETE;
 
 	/* Use alternates if necessary */
-	if (missing_target(obj_req)) {
+	if (missing_target(obj_req->req)) {
 		fetch_alternates(walker, alt->base);
 		if (obj_req->repo->next != NULL) {
 			obj_req->repo =
 				obj_req->repo->next;
-			close(obj_req->local);
-			obj_req->local = -1;
+			release_http_object_request(obj_req->req);
 			start_object_request(walker, obj_req);
 			return;
 		}
@@ -292,8 +114,8 @@ static void release_object_request(struct object_request *obj_req)
 {
 	struct object_request *entry = object_queue_head;
 
-	if (obj_req->local != -1)
-		error("fd leakage in release: %d", obj_req->local);
+	if (obj_req->req !=NULL && obj_req->req->localfile != -1)
+		error("fd leakage in release: %d", obj_req->req->localfile);
 	if (obj_req == object_queue_head) {
 		object_queue_head = obj_req->next;
 	} else {
@@ -303,7 +125,6 @@ static void release_object_request(struct object_request *obj_req)
 			entry->next = entry->next->next;
 	}
 
-	free(obj_req->url);
 	free(obj_req);
 }
 
@@ -331,28 +152,23 @@ static void prefetch(struct walker *walker, unsigned char *sha1)
 	struct object_request *newreq;
 	struct object_request *tail;
 	struct walker_data *data = walker->data;
-	char *filename = sha1_file_name(sha1);
 
 	newreq = xmalloc(sizeof(*newreq));
 	newreq->walker = walker;
 	hashcpy(newreq->sha1, sha1);
 	newreq->repo = data->alt;
-	newreq->url = NULL;
-	newreq->local = -1;
 	newreq->state = WAITING;
-	snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
-	snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
-		 "%s.temp", filename);
-	newreq->slot = NULL;
+	newreq->req = NULL;
 	newreq->next = NULL;
 
+	http_is_verbose = walker->get_verbosely;
+
 	if (object_queue_head == NULL) {
 		object_queue_head = newreq;
 	} else {
 		tail = object_queue_head;
-		while (tail->next != NULL) {
+		while (tail->next != NULL)
 			tail = tail->next;
-		}
 		tail->next = newreq;
 	}
 
@@ -362,95 +178,6 @@ static void prefetch(struct walker *walker, unsigned char *sha1)
 #endif
 }
 
-static int fetch_index(struct walker *walker, struct alt_base *repo, 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;
-	struct walker_data *data = walker->data;
-
-	FILE *indexfile;
-	struct active_request_slot *slot;
-	struct slot_results results;
-
-	if (has_pack_index(sha1))
-		return 0;
-
-	if (walker->get_verbosely)
-		fprintf(stderr, "Getting index for pack %s\n", hex);
-
-	url = xmalloc(strlen(repo->base) + 64);
-	sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, 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",
-			     tmpfile);
-
-	slot = get_active_slot();
-	slot->results = &results;
-	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, data->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 (walker->get_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 (results.curl_result != CURLE_OK) {
-			fclose(indexfile);
-			slot->local = NULL;
-			return error("Unable to get pack index %s\n%s", url,
-				     curl_errorstr);
-		}
-	} else {
-		fclose(indexfile);
-		slot->local = NULL;
-		return error("Unable to start request");
-	}
-
-	fclose(indexfile);
-	slot->local = NULL;
-
-	return move_temp_to_file(tmpfile, filename);
-}
-
-static int setup_index(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
-{
-	struct packed_git *new_pack;
-	if (has_pack_file(sha1))
-		return 0; /* don't list this as something we can get */
-
-	if (fetch_index(walker, repo, sha1))
-		return -1;
-
-	new_pack = parse_pack_index(sha1);
-	if (!new_pack)
-		return -1; /* parse_pack_index() already issued error message */
-	new_pack->next = repo->packs;
-	repo->packs = new_pack;
-	return 0;
-}
-
 static void process_alternates_response(void *callback_data)
 {
 	struct alternates_request *alt_req =
@@ -507,7 +234,8 @@ static void process_alternates_response(void *callback_data)
 			struct alt_base *newalt;
 			char *target = NULL;
 			if (data[i] == '/') {
-				/* This counts
+				/*
+				 * This counts
 				 * http://git.host/pub/scm/linux.git/
 				 * -----------here^
 				 * so memcpy(dst, base, serverlen) will
@@ -520,7 +248,8 @@ static void process_alternates_response(void *callback_data)
 					okay = 1;
 				}
 			} else if (!memcmp(data + i, "../", 3)) {
-				/* Relative URL; chop the corresponding
+				/*
+				 * Relative URL; chop the corresponding
 				 * number of subpath from base (and ../
 				 * from data), and concatenate the result.
 				 *
@@ -549,7 +278,7 @@ static void process_alternates_response(void *callback_data)
 				}
 				/* If the server got removed, give up. */
 				okay = strchr(base, ':') - base + 3 <
-					serverlen;
+				       serverlen;
 			} else if (alt_req->http_specific) {
 				char *colon = strchr(data + i, ':');
 				char *slash = strchr(data + i, '/');
@@ -593,9 +322,11 @@ static void fetch_alternates(struct walker *walker, const char *base)
 	struct alternates_request alt_req;
 	struct walker_data *cdata = walker->data;
 
-	/* If another request has already started fetching alternates,
-	   wait for them to arrive and return to processing this request's
-	   curl message */
+	/*
+	 * If another request has already started fetching alternates,
+	 * wait for them to arrive and return to processing this request's
+	 * curl message
+	 */
 #ifdef USE_CURL_MULTI
 	while (cdata->got_alternates == 0) {
 		step_active_slots();
@@ -615,8 +346,10 @@ static void fetch_alternates(struct walker *walker, const char *base)
 	url = xmalloc(strlen(base) + 31);
 	sprintf(url, "%s/objects/info/http-alternates", base);
 
-	/* Use a callback to process the result, since another request
-	   may fail and need to have alternates loaded before continuing */
+	/*
+	 * Use a callback to process the result, since another request
+	 * may fail and need to have alternates loaded before continuing
+	 */
 	slot = get_active_slot();
 	slot->callback_func = process_alternates_response;
 	alt_req.walker = walker;
@@ -643,15 +376,7 @@ static void fetch_alternates(struct walker *walker, const char *base)
 
 static int fetch_indices(struct walker *walker, struct alt_base *repo)
 {
-	unsigned char sha1[20];
-	char *url;
-	struct strbuf buffer = STRBUF_INIT;
-	char *data;
-	int i = 0;
-	int ret = 0;
-
-	struct active_request_slot *slot;
-	struct slot_results results;
+	int ret;
 
 	if (repo->got_indices)
 		return 0;
@@ -659,76 +384,26 @@ static int fetch_indices(struct walker *walker, struct alt_base *repo)
 	if (walker->get_verbosely)
 		fprintf(stderr, "Getting pack list for %s\n", repo->base);
 
-	url = xmalloc(strlen(repo->base) + 21);
-	sprintf(url, "%s/objects/info/packs", repo->base);
-
-	slot = get_active_slot();
-	slot->results = &results;
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-	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 (results.curl_result != CURLE_OK) {
-			if (missing_target(&results)) {
-				repo->got_indices = 1;
-				goto cleanup;
-			} else {
-				repo->got_indices = 0;
-				ret = error("%s", curl_errorstr);
-				goto cleanup;
-			}
-		}
-	} else {
+	switch (http_get_info_packs(repo->base, &repo->packs)) {
+	case HTTP_OK:
+	case HTTP_MISSING_TARGET:
+		repo->got_indices = 1;
+		ret = 0;
+		break;
+	default:
 		repo->got_indices = 0;
-		ret = error("Unable to start request");
-		goto cleanup;
+		ret = -1;
 	}
 
-	data = buffer.buf;
-	while (i < buffer.len) {
-		switch (data[i]) {
-		case 'P':
-			i++;
-			if (i + 52 <= buffer.len &&
-			    !prefixcmp(data + i, " pack-") &&
-			    !prefixcmp(data + i + 46, ".pack\n")) {
-				get_sha1_hex(data + i + 6, sha1);
-				setup_index(walker, repo, sha1);
-				i += 51;
-				break;
-			}
-		default:
-			while (i < buffer.len && data[i] != '\n')
-				i++;
-		}
-		i++;
-	}
-
-	repo->got_indices = 1;
-cleanup:
-	strbuf_release(&buffer);
-	free(url);
 	return ret;
 }
 
 static int fetch_pack(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
 {
-	char *url;
 	struct packed_git *target;
-	struct packed_git **lst;
-	FILE *packfile;
-	char *filename;
-	char tmpfile[PATH_MAX];
 	int ret;
-	long prev_posn = 0;
-	char range[RANGE_HEADER_SIZE];
-	struct curl_slist *range_header = NULL;
-	struct walker_data *data = walker->data;
-
-	struct active_request_slot *slot;
 	struct slot_results results;
+	struct http_pack_request *preq;
 
 	if (fetch_indices(walker, repo))
 		return -1;
@@ -743,83 +418,37 @@ static int fetch_pack(struct walker *walker, struct alt_base *repo, unsigned cha
 			sha1_to_hex(sha1));
 	}
 
-	url = xmalloc(strlen(repo->base) + 65);
-	sprintf(url, "%s/objects/pack/pack-%s.pack",
-		repo->base, sha1_to_hex(target->sha1));
+	preq = new_http_pack_request(target, repo->base);
+	if (preq == NULL)
+		goto abort;
+	preq->lst = &repo->packs;
+	preq->slot->results = &results;
 
-	filename = sha1_pack_name(target->sha1);
-	snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
-	packfile = fopen(tmpfile, "a");
-	if (!packfile)
-		return error("Unable to open local file %s for pack",
-			     tmpfile);
-
-	slot = get_active_slot();
-	slot->results = &results;
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
-	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
-	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, data->no_pragma_header);
-	slot->local = packfile;
-
-	/* If there is data present from a previous transfer attempt,
-	   resume where it left off */
-	prev_posn = ftell(packfile);
-	if (prev_posn>0) {
-		if (walker->get_verbosely)
-			fprintf(stderr,
-				"Resuming fetch of pack %s at byte %ld\n",
-				sha1_to_hex(target->sha1), 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 (start_active_slot(preq->slot)) {
+		run_active_slot(preq->slot);
 		if (results.curl_result != CURLE_OK) {
-			fclose(packfile);
-			slot->local = NULL;
-			return error("Unable to get pack file %s\n%s", url,
-				     curl_errorstr);
+			error("Unable to get pack file %s\n%s", preq->url,
+			      curl_errorstr);
+			goto abort;
 		}
 	} else {
-		fclose(packfile);
-		slot->local = NULL;
-		return error("Unable to start request");
+		error("Unable to start request");
+		goto abort;
 	}
 
-	target->pack_size = ftell(packfile);
-	fclose(packfile);
-	slot->local = NULL;
-
-	ret = move_temp_to_file(tmpfile, filename);
+	ret = finish_http_pack_request(preq);
+	release_http_pack_request(preq);
 	if (ret)
 		return ret;
 
-	lst = &repo->packs;
-	while (*lst != target)
-		lst = &((*lst)->next);
-	*lst = (*lst)->next;
-
-	if (verify_pack(target))
-		return -1;
-	install_packed_git(target);
-
 	return 0;
+
+abort:
+	return -1;
 }
 
 static void abort_object_request(struct object_request *obj_req)
 {
-	if (obj_req->local >= 0) {
-		close(obj_req->local);
-		obj_req->local = -1;
-	}
-	unlink_or_warn(obj_req->tmpfile);
-	if (obj_req->slot) {
-		release_active_slot(obj_req->slot);
-		obj_req->slot = NULL;
-	}
 	release_object_request(obj_req);
 }
 
@@ -828,6 +457,7 @@ static int fetch_object(struct walker *walker, struct alt_base *repo, unsigned c
 	char *hex = sha1_to_hex(sha1);
 	int ret = 0;
 	struct object_request *obj_req = object_queue_head;
+	struct http_object_request *req;
 
 	while (obj_req != NULL && hashcmp(obj_req->sha1, sha1))
 		obj_req = obj_req->next;
@@ -835,45 +465,55 @@ static int fetch_object(struct walker *walker, struct alt_base *repo, unsigned c
 		return error("Couldn't find request for %s in the queue", hex);
 
 	if (has_sha1_file(obj_req->sha1)) {
+		if (obj_req->req != NULL)
+			abort_http_object_request(obj_req->req);
 		abort_object_request(obj_req);
 		return 0;
 	}
 
 #ifdef USE_CURL_MULTI
-	while (obj_req->state == WAITING) {
+	while (obj_req->state == WAITING)
 		step_active_slots();
-	}
 #else
 	start_object_request(walker, obj_req);
 #endif
 
-	while (obj_req->state == ACTIVE) {
-		run_active_slot(obj_req->slot);
-	}
-	if (obj_req->local != -1) {
-		close(obj_req->local); obj_req->local = -1;
+	/*
+	 * obj_req->req might change when fetching alternates in the callback
+	 * process_object_response; therefore, the "shortcut" variable, req,
+	 * is used only after we're done with slots.
+	 */
+	while (obj_req->state == ACTIVE)
+		run_active_slot(obj_req->req->slot);
+
+	req = obj_req->req;
+
+	if (req->localfile != -1) {
+		close(req->localfile);
+		req->localfile = -1;
 	}
 
 	if (obj_req->state == ABORTED) {
 		ret = error("Request for %s aborted", hex);
-	} else if (obj_req->curl_result != CURLE_OK &&
-		   obj_req->http_code != 416) {
-		if (missing_target(obj_req))
+	} else if (req->curl_result != CURLE_OK &&
+		   req->http_code != 416) {
+		if (missing_target(req))
 			ret = -1; /* Be silent, it is probably in a pack. */
 		else
 			ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
-				    obj_req->errorstr, obj_req->curl_result,
-				    obj_req->http_code, hex);
-	} else if (obj_req->zret != Z_STREAM_END) {
+				    req->errorstr, req->curl_result,
+				    req->http_code, hex);
+	} else if (req->zret != Z_STREAM_END) {
 		walker->corrupt_object_found++;
-		ret = error("File %s (%s) corrupt", hex, obj_req->url);
-	} else if (hashcmp(obj_req->sha1, obj_req->real_sha1)) {
+		ret = error("File %s (%s) corrupt", hex, req->url);
+	} else if (hashcmp(obj_req->sha1, req->real_sha1)) {
 		ret = error("File %s has bad hash", hex);
-	} else if (obj_req->rename < 0) {
+	} else if (req->rename < 0) {
 		ret = error("unable to write sha1 filename %s",
-			    obj_req->filename);
+			    req->filename);
 	}
 
+	release_http_object_request(req);
 	release_object_request(obj_req);
 	return ret;
 }
@@ -903,10 +543,7 @@ static int fetch_ref(struct walker *walker, struct ref *ref)
 
 static void cleanup(struct walker *walker)
 {
-	struct walker_data *data = walker->data;
 	http_cleanup();
-
-	curl_slist_free_all(data->no_pragma_header);
 }
 
 struct walker *get_http_walker(const char *url, struct remote *remote)
@@ -917,8 +554,6 @@ struct walker *get_http_walker(const char *url, struct remote *remote)
 
 	http_init(remote);
 
-	data->no_pragma_header = curl_slist_append(NULL, "Pragma:");
-
 	data->alt = xmalloc(sizeof(*data->alt));
 	data->alt->base = xmalloc(strlen(url) + 1);
 	strcpy(data->alt->base, url);
diff --git a/http.c b/http.c
index 2e3d6493e..95b2137cf 100644
--- a/http.c
+++ b/http.c
@@ -1,7 +1,9 @@
 #include "http.h"
+#include "pack.h"
 
 int data_received;
 int active_requests;
+int http_is_verbose;
 
 #ifdef USE_CURL_MULTI
 static int max_requests = -1;
@@ -10,6 +12,10 @@ static CURLM *curlm;
 #ifndef NO_CURL_EASY_DUPHANDLE
 static CURL *curl_default;
 #endif
+
+#define PREV_BUF_SIZE 4096
+#define RANGE_HEADER_SIZE 30
+
 char curl_errorstr[CURL_ERROR_SIZE];
 
 static int curl_ssl_verify = -1;
@@ -28,6 +34,7 @@ static const char *curl_http_proxy;
 static char *user_name, *user_pass;
 
 static struct curl_slist *pragma_header;
+static struct curl_slist *no_pragma_header;
 
 static struct active_request_slot *active_queue_head;
 
@@ -276,6 +283,8 @@ void http_init(struct remote *remote)
 	char *low_speed_limit;
 	char *low_speed_time;
 
+	http_is_verbose = 0;
+
 	git_config(http_options, NULL);
 
 	curl_global_init(CURL_GLOBAL_ALL);
@@ -284,6 +293,7 @@ void http_init(struct remote *remote)
 		curl_http_proxy = xstrdup(remote->http_proxy);
 
 	pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
+	no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 
 #ifdef USE_CURL_MULTI
 	{
@@ -366,6 +376,9 @@ void http_cleanup(void)
 	curl_slist_free_all(pragma_header);
 	pragma_header = NULL;
 
+	curl_slist_free_all(no_pragma_header);
+	no_pragma_header = NULL;
+
 	if (curl_http_proxy) {
 		free((void *)curl_http_proxy);
 		curl_http_proxy = NULL;
@@ -611,6 +624,7 @@ void finish_all_active_slots(void)
 		}
 }
 
+/* Helpers for modifying and creating URLs */
 static inline int needs_quote(int ch)
 {
 	if (((ch >= 'A') && (ch <= 'Z'))
@@ -631,15 +645,20 @@ static inline int hex(int v)
 		return 'A' + v - 10;
 }
 
+static void end_url_with_slash(struct strbuf *buf, const char *url)
+{
+	strbuf_addstr(buf, url);
+	if (buf->len && buf->buf[buf->len - 1] != '/')
+		strbuf_addstr(buf, "/");
+}
+
 static char *quote_ref_url(const char *base, const char *ref)
 {
 	struct strbuf buf = STRBUF_INIT;
 	const char *cp;
 	int ch;
 
-	strbuf_addstr(&buf, base);
-	if (buf.len && buf.buf[buf.len - 1] != '/' && *ref != '/')
-		strbuf_addstr(&buf, "/");
+	end_url_with_slash(&buf, base);
 
 	for (cp = ref; (ch = *cp) != 0; cp++)
 		if (needs_quote(ch))
@@ -650,41 +669,575 @@ static char *quote_ref_url(const char *base, const char *ref)
 	return strbuf_detach(&buf, NULL);
 }
 
-int http_fetch_ref(const char *base, struct ref *ref)
+void append_remote_object_url(struct strbuf *buf, const char *url,
+			      const char *hex,
+			      int only_two_digit_prefix)
+{
+	strbuf_addf(buf, "%s/objects/%.*s/", url, 2, hex);
+	if (!only_two_digit_prefix)
+		strbuf_addf(buf, "%s", hex+2);
+}
+
+char *get_remote_object_url(const char *url, const char *hex,
+			    int only_two_digit_prefix)
+{
+	struct strbuf buf = STRBUF_INIT;
+	append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
+	return strbuf_detach(&buf, NULL);
+}
+
+/* http_request() targets */
+#define HTTP_REQUEST_STRBUF	0
+#define HTTP_REQUEST_FILE	1
+
+static int http_request(const char *url, void *result, int target, int options)
 {
-	char *url;
-	struct strbuf buffer = STRBUF_INIT;
 	struct active_request_slot *slot;
 	struct slot_results results;
+	struct curl_slist *headers = NULL;
+	struct strbuf buf = STRBUF_INIT;
 	int ret;
 
-	url = quote_ref_url(base, ref->name);
 	slot = get_active_slot();
 	slot->results = &results;
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
+
+	if (result == NULL) {
+		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
+	} else {
+		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
+		curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
+
+		if (target == HTTP_REQUEST_FILE) {
+			long posn = ftell(result);
+			curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+					 fwrite);
+			if (posn > 0) {
+				strbuf_addf(&buf, "Range: bytes=%ld-", posn);
+				headers = curl_slist_append(headers, buf.buf);
+				strbuf_reset(&buf);
+			}
+			slot->local = result;
+		} else
+			curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+					 fwrite_buffer);
+	}
+
+	strbuf_addstr(&buf, "Pragma:");
+	if (options & HTTP_NO_CACHE)
+		strbuf_addstr(&buf, " no-cache");
+
+	headers = curl_slist_append(headers, buf.buf);
+
 	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
+
 	if (start_active_slot(slot)) {
 		run_active_slot(slot);
-		if (results.curl_result == CURLE_OK) {
-			strbuf_rtrim(&buffer);
-			if (buffer.len == 40)
-				ret = get_sha1_hex(buffer.buf, ref->old_sha1);
-			else if (!prefixcmp(buffer.buf, "ref: ")) {
-				ref->symref = xstrdup(buffer.buf + 5);
-				ret = 0;
-			} else
-				ret = 1;
-		} else {
-			ret = error("Couldn't get %s for %s\n%s",
-				    url, ref->name, curl_errorstr);
-		}
+		if (results.curl_result == CURLE_OK)
+			ret = HTTP_OK;
+		else if (missing_target(&results))
+			ret = HTTP_MISSING_TARGET;
+		else
+			ret = HTTP_ERROR;
 	} else {
-		ret = error("Unable to start request");
+		error("Unable to start HTTP request for %s", url);
+		ret = HTTP_START_FAILED;
+	}
+
+	slot->local = NULL;
+	curl_slist_free_all(headers);
+	strbuf_release(&buf);
+
+	return ret;
+}
+
+int http_get_strbuf(const char *url, struct strbuf *result, int options)
+{
+	return http_request(url, result, HTTP_REQUEST_STRBUF, options);
+}
+
+int http_get_file(const char *url, const char *filename, int options)
+{
+	int ret;
+	struct strbuf tmpfile = STRBUF_INIT;
+	FILE *result;
+
+	strbuf_addf(&tmpfile, "%s.temp", filename);
+	result = fopen(tmpfile.buf, "a");
+	if (! result) {
+		error("Unable to open local file %s", tmpfile.buf);
+		ret = HTTP_ERROR;
+		goto cleanup;
+	}
+
+	ret = http_request(url, result, HTTP_REQUEST_FILE, options);
+	fclose(result);
+
+	if ((ret == HTTP_OK) && move_temp_to_file(tmpfile.buf, filename))
+		ret = HTTP_ERROR;
+cleanup:
+	strbuf_release(&tmpfile);
+	return ret;
+}
+
+int http_error(const char *url, int ret)
+{
+	/* http_request has already handled HTTP_START_FAILED. */
+	if (ret != HTTP_START_FAILED)
+		error("%s while accessing %s\n", curl_errorstr, url);
+
+	return ret;
+}
+
+int http_fetch_ref(const char *base, struct ref *ref)
+{
+	char *url;
+	struct strbuf buffer = STRBUF_INIT;
+	int ret = -1;
+
+	url = quote_ref_url(base, ref->name);
+	if (http_get_strbuf(url, &buffer, HTTP_NO_CACHE) == HTTP_OK) {
+		strbuf_rtrim(&buffer);
+		if (buffer.len == 40)
+			ret = get_sha1_hex(buffer.buf, ref->old_sha1);
+		else if (!prefixcmp(buffer.buf, "ref: ")) {
+			ref->symref = xstrdup(buffer.buf + 5);
+			ret = 0;
+		}
 	}
 
 	strbuf_release(&buffer);
 	free(url);
 	return ret;
 }
+
+/* Helpers for fetching packs */
+static int fetch_pack_index(unsigned char *sha1, const char *base_url)
+{
+	int ret = 0;
+	char *hex = xstrdup(sha1_to_hex(sha1));
+	char *filename;
+	char *url;
+	struct strbuf buf = STRBUF_INIT;
+
+	/* Don't use the index if the pack isn't there */
+	end_url_with_slash(&buf, base_url);
+	strbuf_addf(&buf, "objects/pack/pack-%s.pack", hex);
+	url = strbuf_detach(&buf, 0);
+
+	if (http_get_strbuf(url, NULL, 0)) {
+		ret = error("Unable to verify pack %s is available",
+			    hex);
+		goto cleanup;
+	}
+
+	if (has_pack_index(sha1)) {
+		ret = 0;
+		goto cleanup;
+	}
+
+	if (http_is_verbose)
+		fprintf(stderr, "Getting index for pack %s\n", hex);
+
+	end_url_with_slash(&buf, base_url);
+	strbuf_addf(&buf, "objects/pack/pack-%s.idx", hex);
+	url = strbuf_detach(&buf, NULL);
+
+	filename = sha1_pack_index_name(sha1);
+	if (http_get_file(url, filename, 0) != HTTP_OK)
+		ret = error("Unable to get pack index %s\n", url);
+
+cleanup:
+	free(hex);
+	free(url);
+	return ret;
+}
+
+static int fetch_and_setup_pack_index(struct packed_git **packs_head,
+	unsigned char *sha1, const char *base_url)
+{
+	struct packed_git *new_pack;
+
+	if (fetch_pack_index(sha1, base_url))
+		return -1;
+
+	new_pack = parse_pack_index(sha1);
+	if (!new_pack)
+		return -1; /* parse_pack_index() already issued error message */
+	new_pack->next = *packs_head;
+	*packs_head = new_pack;
+	return 0;
+}
+
+int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
+{
+	int ret = 0, i = 0;
+	char *url, *data;
+	struct strbuf buf = STRBUF_INIT;
+	unsigned char sha1[20];
+
+	end_url_with_slash(&buf, base_url);
+	strbuf_addstr(&buf, "objects/info/packs");
+	url = strbuf_detach(&buf, NULL);
+
+	ret = http_get_strbuf(url, &buf, HTTP_NO_CACHE);
+	if (ret != HTTP_OK)
+		goto cleanup;
+
+	data = buf.buf;
+	while (i < buf.len) {
+		switch (data[i]) {
+		case 'P':
+			i++;
+			if (i + 52 <= buf.len &&
+			    !prefixcmp(data + i, " pack-") &&
+			    !prefixcmp(data + i + 46, ".pack\n")) {
+				get_sha1_hex(data + i + 6, sha1);
+				fetch_and_setup_pack_index(packs_head, sha1,
+						      base_url);
+				i += 51;
+				break;
+			}
+		default:
+			while (i < buf.len && data[i] != '\n')
+				i++;
+		}
+		i++;
+	}
+
+cleanup:
+	free(url);
+	return ret;
+}
+
+void release_http_pack_request(struct http_pack_request *preq)
+{
+	if (preq->packfile != NULL) {
+		fclose(preq->packfile);
+		preq->packfile = NULL;
+		preq->slot->local = NULL;
+	}
+	if (preq->range_header != NULL) {
+		curl_slist_free_all(preq->range_header);
+		preq->range_header = NULL;
+	}
+	preq->slot = NULL;
+	free(preq->url);
+}
+
+int finish_http_pack_request(struct http_pack_request *preq)
+{
+	int ret;
+	struct packed_git **lst;
+
+	preq->target->pack_size = ftell(preq->packfile);
+
+	if (preq->packfile != NULL) {
+		fclose(preq->packfile);
+		preq->packfile = NULL;
+		preq->slot->local = NULL;
+	}
+
+	ret = move_temp_to_file(preq->tmpfile, preq->filename);
+	if (ret)
+		return ret;
+
+	lst = preq->lst;
+	while (*lst != preq->target)
+		lst = &((*lst)->next);
+	*lst = (*lst)->next;
+
+	if (verify_pack(preq->target))
+		return -1;
+	install_packed_git(preq->target);
+
+	return 0;
+}
+
+struct http_pack_request *new_http_pack_request(
+	struct packed_git *target, const char *base_url)
+{
+	char *url;
+	char *filename;
+	long prev_posn = 0;
+	char range[RANGE_HEADER_SIZE];
+	struct strbuf buf = STRBUF_INIT;
+	struct http_pack_request *preq;
+
+	preq = xmalloc(sizeof(*preq));
+	preq->target = target;
+	preq->range_header = NULL;
+
+	end_url_with_slash(&buf, base_url);
+	strbuf_addf(&buf, "objects/pack/pack-%s.pack",
+		sha1_to_hex(target->sha1));
+	url = strbuf_detach(&buf, NULL);
+	preq->url = xstrdup(url);
+
+	filename = sha1_pack_name(target->sha1);
+	snprintf(preq->filename, sizeof(preq->filename), "%s", filename);
+	snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp", filename);
+	preq->packfile = fopen(preq->tmpfile, "a");
+	if (!preq->packfile) {
+		error("Unable to open local file %s for pack",
+		      preq->tmpfile);
+		goto abort;
+	}
+
+	preq->slot = get_active_slot();
+	preq->slot->local = preq->packfile;
+	curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
+	curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
+	curl_easy_setopt(preq->slot->curl, CURLOPT_URL, url);
+	curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
+		no_pragma_header);
+
+	/*
+	 * If there is data present from a previous transfer attempt,
+	 * resume where it left off
+	 */
+	prev_posn = ftell(preq->packfile);
+	if (prev_posn>0) {
+		if (http_is_verbose)
+			fprintf(stderr,
+				"Resuming fetch of pack %s at byte %ld\n",
+				sha1_to_hex(target->sha1), prev_posn);
+		sprintf(range, "Range: bytes=%ld-", prev_posn);
+		preq->range_header = curl_slist_append(NULL, range);
+		curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
+			preq->range_header);
+	}
+
+	return preq;
+
+abort:
+	free(filename);
+	return NULL;
+}
+
+/* Helpers for fetching objects (loose) */
+static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
+			       void *data)
+{
+	unsigned char expn[4096];
+	size_t size = eltsize * nmemb;
+	int posn = 0;
+	struct http_object_request *freq =
+		(struct http_object_request *)data;
+	do {
+		ssize_t retval = xwrite(freq->localfile,
+					(char *) ptr + posn, size - posn);
+		if (retval < 0)
+			return posn;
+		posn += retval;
+	} while (posn < size);
+
+	freq->stream.avail_in = size;
+	freq->stream.next_in = ptr;
+	do {
+		freq->stream.next_out = expn;
+		freq->stream.avail_out = sizeof(expn);
+		freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
+		git_SHA1_Update(&freq->c, expn,
+				sizeof(expn) - freq->stream.avail_out);
+	} while (freq->stream.avail_in && freq->zret == Z_OK);
+	data_received++;
+	return size;
+}
+
+struct http_object_request *new_http_object_request(const char *base_url,
+	unsigned char *sha1)
+{
+	char *hex = sha1_to_hex(sha1);
+	char *filename;
+	char prevfile[PATH_MAX];
+	char *url;
+	int prevlocal;
+	unsigned char prev_buf[PREV_BUF_SIZE];
+	ssize_t prev_read = 0;
+	long prev_posn = 0;
+	char range[RANGE_HEADER_SIZE];
+	struct curl_slist *range_header = NULL;
+	struct http_object_request *freq;
+
+	freq = xmalloc(sizeof(*freq));
+	hashcpy(freq->sha1, sha1);
+	freq->localfile = -1;
+
+	filename = sha1_file_name(sha1);
+	snprintf(freq->filename, sizeof(freq->filename), "%s", filename);
+	snprintf(freq->tmpfile, sizeof(freq->tmpfile),
+		 "%s.temp", filename);
+
+	snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
+	unlink_or_warn(prevfile);
+	rename(freq->tmpfile, prevfile);
+	unlink_or_warn(freq->tmpfile);
+
+	if (freq->localfile != -1)
+		error("fd leakage in start: %d", freq->localfile);
+	freq->localfile = open(freq->tmpfile,
+			       O_WRONLY | O_CREAT | O_EXCL, 0666);
+	/*
+	 * This could have failed due to the "lazy directory creation";
+	 * try to mkdir the last path component.
+	 */
+	if (freq->localfile < 0 && errno == ENOENT) {
+		char *dir = strrchr(freq->tmpfile, '/');
+		if (dir) {
+			*dir = 0;
+			mkdir(freq->tmpfile, 0777);
+			*dir = '/';
+		}
+		freq->localfile = open(freq->tmpfile,
+				       O_WRONLY | O_CREAT | O_EXCL, 0666);
+	}
+
+	if (freq->localfile < 0) {
+		error("Couldn't create temporary file %s for %s: %s",
+		      freq->tmpfile, freq->filename, strerror(errno));
+		goto abort;
+	}
+
+	memset(&freq->stream, 0, sizeof(freq->stream));
+
+	git_inflate_init(&freq->stream);
+
+	git_SHA1_Init(&freq->c);
+
+	url = get_remote_object_url(base_url, hex, 0);
+	freq->url = xstrdup(url);
+
+	/*
+	 * If a previous temp file is present, process what was already
+	 * fetched.
+	 */
+	prevlocal = open(prevfile, O_RDONLY);
+	if (prevlocal != -1) {
+		do {
+			prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
+			if (prev_read>0) {
+				if (fwrite_sha1_file(prev_buf,
+						     1,
+						     prev_read,
+						     freq) == prev_read) {
+					prev_posn += prev_read;
+				} else {
+					prev_read = -1;
+				}
+			}
+		} while (prev_read > 0);
+		close(prevlocal);
+	}
+	unlink_or_warn(prevfile);
+
+	/*
+	 * Reset inflate/SHA1 if there was an error reading the previous temp
+	 * file; also rewind to the beginning of the local file.
+	 */
+	if (prev_read == -1) {
+		memset(&freq->stream, 0, sizeof(freq->stream));
+		git_inflate_init(&freq->stream);
+		git_SHA1_Init(&freq->c);
+		if (prev_posn>0) {
+			prev_posn = 0;
+			lseek(freq->localfile, 0, SEEK_SET);
+			ftruncate(freq->localfile, 0);
+		}
+	}
+
+	freq->slot = get_active_slot();
+
+	curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
+	curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
+	curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
+	curl_easy_setopt(freq->slot->curl, CURLOPT_URL, url);
+	curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
+
+	/*
+	 * If we have successfully processed data from a previous fetch
+	 * attempt, only fetch the data we don't already have.
+	 */
+	if (prev_posn>0) {
+		if (http_is_verbose)
+			fprintf(stderr,
+				"Resuming fetch of object %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(freq->slot->curl,
+				 CURLOPT_HTTPHEADER, range_header);
+	}
+
+	return freq;
+
+	free(url);
+abort:
+	free(filename);
+	free(freq);
+	return NULL;
+}
+
+void process_http_object_request(struct http_object_request *freq)
+{
+	if (freq->slot == NULL)
+		return;
+	freq->curl_result = freq->slot->curl_result;
+	freq->http_code = freq->slot->http_code;
+	freq->slot = NULL;
+}
+
+int finish_http_object_request(struct http_object_request *freq)
+{
+	struct stat st;
+
+	close(freq->localfile);
+	freq->localfile = -1;
+
+	process_http_object_request(freq);
+
+	if (freq->http_code == 416) {
+		fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
+	} else if (freq->curl_result != CURLE_OK) {
+		if (stat(freq->tmpfile, &st) == 0)
+			if (st.st_size == 0)
+				unlink_or_warn(freq->tmpfile);
+		return -1;
+	}
+
+	git_inflate_end(&freq->stream);
+	git_SHA1_Final(freq->real_sha1, &freq->c);
+	if (freq->zret != Z_STREAM_END) {
+		unlink_or_warn(freq->tmpfile);
+		return -1;
+	}
+	if (hashcmp(freq->sha1, freq->real_sha1)) {
+		unlink_or_warn(freq->tmpfile);
+		return -1;
+	}
+	freq->rename =
+		move_temp_to_file(freq->tmpfile, freq->filename);
+
+	return freq->rename;
+}
+
+void abort_http_object_request(struct http_object_request *freq)
+{
+	unlink_or_warn(freq->tmpfile);
+
+	release_http_object_request(freq);
+}
+
+void release_http_object_request(struct http_object_request *freq)
+{
+	if (freq->localfile != -1) {
+		close(freq->localfile);
+		freq->localfile = -1;
+	}
+	if (freq->url != NULL) {
+		free(freq->url);
+		freq->url = NULL;
+	}
+	freq->slot = NULL;
+}
diff --git a/http.h b/http.h
index 26abebed1..4c4e99c2f 100644
--- a/http.h
+++ b/http.h
@@ -93,6 +93,7 @@ extern void http_cleanup(void);
 
 extern int data_received;
 extern int active_requests;
+extern int http_is_verbose;
 
 extern char curl_errorstr[CURL_ERROR_SIZE];
 
@@ -109,6 +110,90 @@ static inline int missing__target(int code, int result)
 
 #define missing_target(a) missing__target((a)->http_code, (a)->curl_result)
 
+/* Helpers for modifying and creating URLs */
+extern void append_remote_object_url(struct strbuf *buf, const char *url,
+				     const char *hex,
+				     int only_two_digit_prefix);
+extern char *get_remote_object_url(const char *url, const char *hex,
+				   int only_two_digit_prefix);
+
+/* Options for http_request_*() */
+#define HTTP_NO_CACHE		1
+
+/* Return values for http_request_*() */
+#define HTTP_OK			0
+#define HTTP_MISSING_TARGET	1
+#define HTTP_ERROR		2
+#define HTTP_START_FAILED	3
+
+/*
+ * Requests an url and stores the result in a strbuf.
+ *
+ * If the result pointer is NULL, a HTTP HEAD request is made instead of GET.
+ */
+int http_get_strbuf(const char *url, struct strbuf *result, int options);
+
+/*
+ * Downloads an url and stores the result in the given file.
+ *
+ * If a previous interrupted download is detected (i.e. a previous temporary
+ * file is still around) the download is resumed.
+ */
+int http_get_file(const char *url, const char *filename, int options);
+
+/*
+ * Prints an error message using error() containing url and curl_errorstr,
+ * and returns ret.
+ */
+int http_error(const char *url, int ret);
+
 extern int http_fetch_ref(const char *base, struct ref *ref);
 
+/* Helpers for fetching packs */
+extern int http_get_info_packs(const char *base_url,
+	struct packed_git **packs_head);
+
+struct http_pack_request
+{
+	char *url;
+	struct packed_git *target;
+	struct packed_git **lst;
+	FILE *packfile;
+	char filename[PATH_MAX];
+	char tmpfile[PATH_MAX];
+	struct curl_slist *range_header;
+	struct active_request_slot *slot;
+};
+
+extern struct http_pack_request *new_http_pack_request(
+	struct packed_git *target, const char *base_url);
+extern int finish_http_pack_request(struct http_pack_request *preq);
+extern void release_http_pack_request(struct http_pack_request *preq);
+
+/* Helpers for fetching object */
+struct http_object_request
+{
+	char *url;
+	char filename[PATH_MAX];
+	char tmpfile[PATH_MAX];
+	int localfile;
+	CURLcode curl_result;
+	char errorstr[CURL_ERROR_SIZE];
+	long http_code;
+	unsigned char sha1[20];
+	unsigned char real_sha1[20];
+	git_SHA_CTX c;
+	z_stream stream;
+	int zret;
+	int rename;
+	struct active_request_slot *slot;
+};
+
+extern struct http_object_request *new_http_object_request(
+	const char *base_url, unsigned char *sha1);
+extern void process_http_object_request(struct http_object_request *freq);
+extern int finish_http_object_request(struct http_object_request *freq);
+extern void abort_http_object_request(struct http_object_request *freq);
+extern void release_http_object_request(struct http_object_request *freq);
+
 #endif /* HTTP_H */
diff --git a/pack-check.c b/pack-check.c
index 90c33b1b8..166ca703c 100644
--- a/pack-check.c
+++ b/pack-check.c
@@ -49,7 +49,7 @@ static int verify_packfile(struct packed_git *p,
 	const unsigned char *index_base = p->index_data;
 	git_SHA_CTX ctx;
 	unsigned char sha1[20], *pack_sig;
-	off_t offset = 0, pack_sig_ofs = p->pack_size - 20;
+	off_t offset = 0, pack_sig_ofs = 0;
 	uint32_t nr_objects, i;
 	int err = 0;
 	struct idx_entry *entries;
@@ -61,14 +61,16 @@ static int verify_packfile(struct packed_git *p,
 	 */
 
 	git_SHA1_Init(&ctx);
-	while (offset < pack_sig_ofs) {
+	do {
 		unsigned int remaining;
 		unsigned char *in = use_pack(p, w_curs, offset, &remaining);
 		offset += remaining;
+		if (!pack_sig_ofs)
+			pack_sig_ofs = p->pack_size - 20;
 		if (offset > pack_sig_ofs)
 			remaining -= (unsigned int)(offset - pack_sig_ofs);
 		git_SHA1_Update(&ctx, in, remaining);
-	}
+	} while (offset < pack_sig_ofs);
 	git_SHA1_Final(sha1, &ctx);
 	pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
 	if (hashcmp(sha1, pack_sig))
diff --git a/t/t5540-http-push.sh b/t/t5540-http-push.sh
index 5fe479e1c..f4a2cf6c1 100755
--- a/t/t5540-http-push.sh
+++ b/t/t5540-http-push.sh
@@ -67,6 +67,42 @@ test_expect_success ' push to remote repository with unpacked refs' '
 	 test $HEAD = $(git rev-parse --verify HEAD))
 '
 
+test_expect_success 'http-push fetches unpacked objects' '
+	cp -R "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git \
+		"$HTTPD_DOCUMENT_ROOT_PATH"/test_repo_unpacked.git &&
+
+	git clone $HTTPD_URL/test_repo_unpacked.git \
+		"$ROOT_PATH"/fetch_unpacked &&
+
+	# By reset, we force git to retrieve the object
+	(cd "$ROOT_PATH"/fetch_unpacked &&
+	 git reset --hard HEAD^ &&
+	 git remote rm origin &&
+	 git reflog expire --expire=0 --all &&
+	 git prune &&
+	 git push -f -v $HTTPD_URL/test_repo_unpacked.git master)
+'
+
+test_expect_success 'http-push fetches packed objects' '
+	cp -R "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git \
+		"$HTTPD_DOCUMENT_ROOT_PATH"/test_repo_packed.git &&
+
+	git clone $HTTPD_URL/test_repo_packed.git \
+		"$ROOT_PATH"/test_repo_clone_packed &&
+
+	(cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo_packed.git &&
+	 git --bare repack &&
+	 git --bare prune-packed) &&
+
+	# By reset, we force git to retrieve the packed object
+	(cd "$ROOT_PATH"/test_repo_clone_packed &&
+	 git reset --hard HEAD^ &&
+	 git remote rm origin &&
+	 git reflog expire --expire=0 --all &&
+	 git prune &&
+	 git push -f -v $HTTPD_URL/test_repo_packed.git master)
+'
+
 test_expect_success 'create and delete remote branch' '
 	cd "$ROOT_PATH"/test_repo_clone &&
 	git checkout -b dev &&
diff --git a/t/t5550-http-fetch.sh b/t/t5550-http-fetch.sh
index 05b1b62cb..0e6932465 100755
--- a/t/t5550-http-fetch.sh
+++ b/t/t5550-http-fetch.sh
@@ -53,5 +53,13 @@ test_expect_success 'http remote detects correct HEAD' '
 	)
 '
 
+test_expect_success 'fetch packed objects' '
+	cp -R "$HTTPD_DOCUMENT_ROOT_PATH"/repo.git "$HTTPD_DOCUMENT_ROOT_PATH"/repo_pack.git &&
+	cd "$HTTPD_DOCUMENT_ROOT_PATH"/repo_pack.git &&
+	git --bare repack &&
+	git --bare prune-packed &&
+	git clone $HTTPD_URL/repo_pack.git
+'
+
 stop_httpd
 test_done
diff --git a/transport.c b/transport.c
index d8a2392a6..501a77b24 100644
--- a/transport.c
+++ b/transport.c
@@ -439,9 +439,7 @@ static struct ref *get_refs_via_curl(struct transport *transport, int for_push)
 	char *ref_name;
 	char *refs_url;
 	int i = 0;
-
-	struct active_request_slot *slot;
-	struct slot_results results;
+	int http_ret;
 
 	struct ref *refs = NULL;
 	struct ref *ref = NULL;
@@ -461,25 +459,16 @@ static struct ref *get_refs_via_curl(struct transport *transport, int for_push)
 	refs_url = xmalloc(strlen(transport->url) + 11);
 	sprintf(refs_url, "%s/info/refs", transport->url);
 
-	slot = get_active_slot();
-	slot->results = &results;
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-	curl_easy_setopt(slot->curl, CURLOPT_URL, refs_url);
-	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
-
-	if (start_active_slot(slot)) {
-		run_active_slot(slot);
-		if (results.curl_result != CURLE_OK) {
-			strbuf_release(&buffer);
-			if (missing_target(&results))
-				die("%s not found: did you run git update-server-info on the server?", refs_url);
-			else
-				die("%s download error - %s", refs_url, curl_errorstr);
-		}
-	} else {
-		strbuf_release(&buffer);
-		die("Unable to start HTTP request");
+	http_ret = http_get_strbuf(refs_url, &buffer, HTTP_NO_CACHE);
+	switch (http_ret) {
+	case HTTP_OK:
+		break;
+	case HTTP_MISSING_TARGET:
+		die("%s not found: did you run git update-server-info on the"
+		    " server?", refs_url);
+	default:
+		http_error(refs_url, http_ret);
+		die("HTTP request failed");
 	}
 
 	data = buffer.buf;
@@ -519,6 +508,8 @@ static struct ref *get_refs_via_curl(struct transport *transport, int for_push)
 		free(ref);
 	}
 
+	strbuf_release(&buffer);
+	free(refs_url);
 	return refs;
 }