gitweb: Make blame and snapshot a feature.
[gitweb.git] / http-fetch.c
index 71a8c60b56914ca579db3da1d2bef6795acc7bf9..7f07d2a967fdecb497344817700962e9e213d3dd 100644 (file)
 #include "commit.h"
 #include "pack.h"
 #include "fetch.h"
+#include "http.h"
+
+#ifndef NO_EXPAT
+#include <expat.h>
+
+/* Definitions for DAV requests */
+#define DAV_PROPFIND "PROPFIND"
+#define DAV_PROPFIND_RESP ".multistatus.response"
+#define DAV_PROPFIND_NAME ".multistatus.response.href"
+#define DAV_PROPFIND_COLLECTION ".multistatus.response.propstat.prop.resourcetype.collection"
+#define PROPFIND_ALL_REQUEST "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:allprop/>\n</D:propfind>"
+
+/* Definitions for processing XML DAV responses */
+#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
 
-#include <curl/curl.h>
-#include <curl/easy.h>
+/* Flags that control remote_ls processing */
+#define PROCESS_FILES (1u << 0)
+#define PROCESS_DIRS  (1u << 1)
+#define RECURSIVE     (1u << 2)
 
-#if LIBCURL_VERSION_NUM < 0x070704
-#define curl_global_cleanup() do { /* nothing */ } while(0)
-#endif
-#if LIBCURL_VERSION_NUM < 0x070800
-#define curl_global_init(a) do { /* nothing */ } while(0)
+/* Flags that remote_ls passes to callback functions */
+#define IS_DIR (1u << 0)
 #endif
 
 #define PREV_BUF_SIZE 4096
 #define RANGE_HEADER_SIZE 30
 
-static CURL *curl;
-static struct curl_slist *no_pragma_header;
-static struct curl_slist *no_range_header;
-static char curl_errorstr[CURL_ERROR_SIZE];
+static int commits_on_stdin;
+
+static int got_alternates = -1;
+static int corrupt_object_found;
 
-static char *initial_base;
+static struct curl_slist *no_pragma_header;
 
 struct alt_base
 {
-       char *base;
+       const char *base;
+       int path_len;
        int got_indices;
        struct packed_git *packs;
        struct alt_base *next;
 };
 
-static struct alt_base *alt = NULL;
+static struct alt_base *alt;
 
-static SHA_CTX c;
-static z_stream stream;
+enum object_request_state {
+       WAITING,
+       ABORTED,
+       ACTIVE,
+       COMPLETE,
+};
 
-static int local;
-static int zret;
+struct object_request
+{
+       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];
+       SHA_CTX c;
+       z_stream stream;
+       int zret;
+       int rename;
+       struct active_request_slot *slot;
+       struct object_request *next;
+};
 
-static int curl_ssl_verify;
-static char *ssl_cert;
-static char *ssl_key;
-static char *ssl_capath;
-static char *ssl_cainfo;
+struct alternates_request {
+       const char *base;
+       char *url;
+       struct buffer *buffer;
+       struct active_request_slot *slot;
+       int http_specific;
+};
 
-struct buffer
+#ifndef NO_EXPAT
+struct xml_ctx
 {
-        size_t posn;
-        size_t size;
-        void *buffer;
+       char *name;
+       int len;
+       char *cdata;
+       void (*userFunc)(struct xml_ctx *ctx, int tag_closed);
+       void *userData;
 };
 
-static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
-                            struct buffer *buffer)
+struct remote_ls_ctx
 {
-        size_t size = eltsize * nmemb;
-        if (size > buffer->size - buffer->posn)
-                size = buffer->size - buffer->posn;
-        memcpy(buffer->buffer + buffer->posn, ptr, size);
-        buffer->posn += size;
-        return size;
-}
+       struct alt_base *repo;
+       char *path;
+       void (*userFunc)(struct remote_ls_ctx *ls);
+       void *userData;
+       int flags;
+       char *dentry_name;
+       int dentry_flags;
+       int rc;
+       struct remote_ls_ctx *parent;
+};
+#endif
+
+static struct object_request *object_queue_head;
 
 static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
                               void *data)
@@ -69,73 +122,327 @@ static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
        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 = write(local, ptr + posn, size - posn);
+               ssize_t retval = write(obj_req->local,
+                                      (char *) ptr + posn, size - posn);
                if (retval < 0)
                        return posn;
                posn += retval;
        } while (posn < size);
 
-       stream.avail_in = size;
-       stream.next_in = ptr;
+       obj_req->stream.avail_in = size;
+       obj_req->stream.next_in = ptr;
        do {
-               stream.next_out = expn;
-               stream.avail_out = sizeof(expn);
-               zret = inflate(&stream, Z_SYNC_FLUSH);
-               SHA1_Update(&c, expn, sizeof(expn) - stream.avail_out);
-       } while (stream.avail_in && zret == Z_OK);
+               obj_req->stream.next_out = expn;
+               obj_req->stream.avail_out = sizeof(expn);
+               obj_req->zret = inflate(&obj_req->stream, Z_SYNC_FLUSH);
+               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;
 }
 
-void prefetch(unsigned char *sha1)
+static void fetch_alternates(const char *base);
+
+static void process_object_response(void *callback_data);
+
+static void start_object_request(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;
+
+       snprintf(prevfile, sizeof(prevfile), "%s.prev", obj_req->filename);
+       unlink(prevfile);
+       rename(obj_req->tmpfile, prevfile);
+       unlink(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) {
+               obj_req->state = ABORTED;
+               error("Couldn't create temporary file %s for %s: %s",
+                     obj_req->tmpfile, obj_req->filename, strerror(errno));
+               return;
+       }
+
+       memset(&obj_req->stream, 0, sizeof(obj_req->stream));
+
+       inflateInit(&obj_req->stream);
+
+       SHA1_Init(&obj_req->c);
+
+       url = xmalloc(strlen(obj_req->repo->base) + 50);
+       obj_req->url = xmalloc(strlen(obj_req->repo->base) + 50);
+       strcpy(url, obj_req->repo->base);
+       posn = url + strlen(obj_req->repo->base);
+       strcpy(posn, "objects/");
+       posn += 8;
+       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 = read(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(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));
+               inflateInit(&obj_req->stream);
+               SHA1_Init(&obj_req->c);
+               if (prev_posn>0) {
+                       prev_posn = 0;
+                       lseek(obj_req->local, SEEK_SET, 0);
+                       ftruncate(obj_req->local, 0);
+               }
+       }
+
+       slot = get_active_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, 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 (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);
+               return;
+       }
+}
+
+static void finish_object_request(struct object_request *obj_req)
 {
+       struct stat st;
+
+       fchmod(obj_req->local, 0444);
+       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(obj_req->tmpfile);
+               return;
+       }
+
+       inflateEnd(&obj_req->stream);
+       SHA1_Final(obj_req->real_sha1, &obj_req->c);
+       if (obj_req->zret != Z_STREAM_END) {
+               unlink(obj_req->tmpfile);
+               return;
+       }
+       if (memcmp(obj_req->sha1, obj_req->real_sha1, 20)) {
+               unlink(obj_req->tmpfile);
+               return;
+       }
+       obj_req->rename =
+               move_temp_to_file(obj_req->tmpfile, obj_req->filename);
+
+       if (obj_req->rename == 0)
+               pull_say("got %s\n", sha1_to_hex(obj_req->sha1));
 }
 
-int relink_or_rename(char *old, char *new) {
-       int ret;
+static void process_object_response(void *callback_data)
+{
+       struct object_request *obj_req =
+               (struct object_request *)callback_data;
+
+       obj_req->curl_result = obj_req->slot->curl_result;
+       obj_req->http_code = obj_req->slot->http_code;
+       obj_req->slot = NULL;
+       obj_req->state = COMPLETE;
+
+       /* Use alternates if necessary */
+       if (obj_req->http_code == 404 ||
+           obj_req->curl_result == CURLE_FILE_COULDNT_READ_FILE) {
+               fetch_alternates(alt->base);
+               if (obj_req->repo->next != NULL) {
+                       obj_req->repo =
+                               obj_req->repo->next;
+                       close(obj_req->local);
+                       obj_req->local = -1;
+                       start_object_request(obj_req);
+                       return;
+               }
+       }
 
-       ret = link(old, new);
-       if (ret < 0) {
-               /* Same Coda hack as in write_sha1_file(sha1_file.c) */
-               ret = errno;
-               if (ret == EXDEV && !rename(old, new))
-                       return 0;
+       finish_object_request(obj_req);
+}
+
+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 == object_queue_head) {
+               object_queue_head = obj_req->next;
+       } else {
+               while (entry->next != NULL && entry->next != obj_req)
+                       entry = entry->next;
+               if (entry->next == obj_req)
+                       entry->next = entry->next->next;
        }
-       unlink(old);
-       if (ret) {
-               if (ret != EEXIST)
-                       return ret;
+
+       free(obj_req->url);
+       free(obj_req);
+}
+
+#ifdef USE_CURL_MULTI
+void fill_active_slots(void)
+{
+       struct object_request *obj_req = object_queue_head;
+       struct active_request_slot *slot = active_queue_head;
+       int num_transfers;
+
+       while (active_requests < max_requests && obj_req != NULL) {
+               if (obj_req->state == WAITING) {
+                       if (has_sha1_file(obj_req->sha1))
+                               obj_req->state = COMPLETE;
+                       else
+                               start_object_request(obj_req);
+                       curl_multi_perform(curlm, &num_transfers);
+               }
+               obj_req = obj_req->next;
        }
 
-       return 0;
+       while (slot != NULL) {
+               if (!slot->in_use && slot->curl != NULL) {
+                       curl_easy_cleanup(slot->curl);
+                       slot->curl = NULL;
+               }
+               slot = slot->next;
+       }
 }
+#endif
+
+void prefetch(unsigned char *sha1)
+{
+       struct object_request *newreq;
+       struct object_request *tail;
+       char *filename = sha1_file_name(sha1);
+
+       newreq = xmalloc(sizeof(*newreq));
+       memcpy(newreq->sha1, sha1, 20);
+       newreq->repo = 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->next = NULL;
+
+       if (object_queue_head == NULL) {
+               object_queue_head = newreq;
+       } else {
+               tail = object_queue_head;
+               while (tail->next != NULL) {
+                       tail = tail->next;
+               }
+               tail->next = newreq;
+       }
 
-static int got_alternates = 0;
+#ifdef USE_CURL_MULTI
+       fill_active_slots();
+       step_active_slots();
+#endif
+}
 
 static int fetch_index(struct alt_base *repo, unsigned char *sha1)
 {
+       char *hex = sha1_to_hex(sha1);
        char *filename;
        char *url;
        char tmpfile[PATH_MAX];
-       int ret;
        long prev_posn = 0;
        char range[RANGE_HEADER_SIZE];
        struct curl_slist *range_header = NULL;
-       CURLcode curl_result;
 
        FILE *indexfile;
+       struct active_request_slot *slot;
+       struct slot_results results;
 
        if (has_pack_index(sha1))
                return 0;
 
        if (get_verbosely)
-               fprintf(stderr, "Getting index for pack %s\n",
-                       sha1_to_hex(sha1));
-       
+               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, sha1_to_hex(sha1));
-       
+       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");
@@ -143,12 +450,14 @@ static int fetch_index(struct alt_base *repo, unsigned char *sha1)
                return error("Unable to open local file %s for pack index",
                             filename);
 
-       curl_easy_setopt(curl, CURLOPT_FILE, indexfile);
-       curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite);
-       curl_easy_setopt(curl, CURLOPT_URL, url);
-       curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header);
-       curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_errorstr);
-       
+       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, 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);
@@ -156,37 +465,34 @@ static int fetch_index(struct alt_base *repo, unsigned char *sha1)
                if (get_verbosely)
                        fprintf(stderr,
                                "Resuming fetch of index for pack %s at byte %ld\n",
-                               sha1_to_hex(sha1), prev_posn);
+                               hex, prev_posn);
                sprintf(range, "Range: bytes=%ld-", prev_posn);
                range_header = curl_slist_append(range_header, range);
-               curl_easy_setopt(curl, CURLOPT_HTTPHEADER, range_header);
+               curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
        }
 
-       /* Clear out the Range: header after performing the request, so
-          other curl requests don't inherit inappropriate header data */
-       curl_result = curl_easy_perform(curl);
-       curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_range_header);
-       if (curl_result != 0) {
+       if (start_active_slot(slot)) {
+               run_active_slot(slot);
+               if (results.curl_result != CURLE_OK) {
+                       fclose(indexfile);
+                       return error("Unable to get pack index %s\n%s", url,
+                                    curl_errorstr);
+               }
+       } else {
                fclose(indexfile);
-               return error("Unable to get pack index %s\n%s", url,
-                            curl_errorstr);
+               return error("Unable to start request");
        }
 
        fclose(indexfile);
 
-       ret = relink_or_rename(tmpfile, filename);
-       if (ret)
-               return error("unable to write index filename %s: %s",
-                            filename, strerror(ret));
-
-       return 0;
+       return move_temp_to_file(tmpfile, filename);
 }
 
 static int setup_index(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
+               return 0; /* don't list this as something we can get */
 
        if (fetch_index(repo, sha1))
                return -1;
@@ -197,63 +503,68 @@ static int setup_index(struct alt_base *repo, unsigned char *sha1)
        return 0;
 }
 
-static int fetch_alternates(char *base)
+static void process_alternates_response(void *callback_data)
 {
-       int ret = 0;
-       struct buffer buffer;
-       char *url;
+       struct alternates_request *alt_req =
+               (struct alternates_request *)callback_data;
+       struct active_request_slot *slot = alt_req->slot;
+       struct alt_base *tail = alt;
+       const char *base = alt_req->base;
+       static const char null_byte = '\0';
        char *data;
        int i = 0;
-       int http_specific = 1;
-       if (got_alternates)
-               return 0;
-       data = xmalloc(4096);
-       buffer.size = 4095;
-       buffer.posn = 0;
-       buffer.buffer = data;
-
-       if (get_verbosely)
-               fprintf(stderr, "Getting alternates list\n");
-       
-       url = xmalloc(strlen(base) + 31);
-       sprintf(url, "%s/objects/info/http-alternates", base);
-
-       curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
-       curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-       curl_easy_setopt(curl, CURLOPT_URL, url);
 
-       if (curl_easy_perform(curl) || !buffer.posn) {
-               http_specific = 0;
-
-               sprintf(url, "%s/objects/info/alternates", base);
-               
-               curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
-               curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-               curl_easy_setopt(curl, CURLOPT_URL, url);
-               
-               if (curl_easy_perform(curl)) {
-                       return 0;
+       if (alt_req->http_specific) {
+               if (slot->curl_result != CURLE_OK ||
+                   !alt_req->buffer->posn) {
+
+                       /* Try reusing the slot to get non-http alternates */
+                       alt_req->http_specific = 0;
+                       sprintf(alt_req->url, "%s/objects/info/alternates",
+                               base);
+                       curl_easy_setopt(slot->curl, CURLOPT_URL,
+                                        alt_req->url);
+                       active_requests++;
+                       slot->in_use = 1;
+                       if (slot->finished != NULL)
+                               (*slot->finished) = 0;
+                       if (!start_active_slot(slot)) {
+                               got_alternates = -1;
+                               slot->in_use = 0;
+                               if (slot->finished != NULL)
+                                       (*slot->finished) = 1;
+                       }
+                       return;
+               }
+       } else if (slot->curl_result != CURLE_OK) {
+               if (slot->http_code != 404 &&
+                   slot->curl_result != CURLE_FILE_COULDNT_READ_FILE) {
+                       got_alternates = -1;
+                       return;
                }
        }
 
-       data[buffer.posn] = '\0';
+       fwrite_buffer(&null_byte, 1, 1, alt_req->buffer);
+       alt_req->buffer->posn--;
+       data = alt_req->buffer->buffer;
 
-       while (i < buffer.posn) {
+       while (i < alt_req->buffer->posn) {
                int posn = i;
-               while (posn < buffer.posn && data[posn] != '\n')
+               while (posn < alt_req->buffer->posn && data[posn] != '\n')
                        posn++;
                if (data[posn] == '\n') {
                        int okay = 0;
                        int serverlen = 0;
                        struct alt_base *newalt;
                        char *target = NULL;
+                       char *path;
                        if (data[i] == '/') {
                                serverlen = strchr(base + 8, '/') - base;
                                okay = 1;
                        } else if (!memcmp(data + i, "../", 3)) {
                                i += 3;
                                serverlen = strlen(base);
-                               while (i + 2 < posn && 
+                               while (i + 2 < posn &&
                                       !memcmp(data + i, "../", 3)) {
                                        do {
                                                serverlen--;
@@ -261,10 +572,10 @@ static int fetch_alternates(char *base)
                                                 base[serverlen - 1] != '/');
                                        i += 3;
                                }
-                               // If the server got removed, give up.
-                               okay = strchr(base, ':') - base + 3 < 
+                               /* If the server got removed, give up. */
+                               okay = strchr(base, ':') - base + 3 <
                                        serverlen;
-                       } else if (http_specific) {
+                       } else if (alt_req->http_specific) {
                                char *colon = strchr(data + i, ':');
                                char *slash = strchr(data + i, '/');
                                if (colon && slash && colon < data + posn &&
@@ -272,32 +583,300 @@ static int fetch_alternates(char *base)
                                        okay = 1;
                                }
                        }
-                       // skip 'objects' at end
+                       /* skip 'objects' at end */
                        if (okay) {
                                target = xmalloc(serverlen + posn - i - 6);
-                               strncpy(target, base, serverlen);
-                               strncpy(target + serverlen, data + i,
-                                       posn - i - 7);
-                               target[serverlen + posn - i - 7] = '\0';
+                               strlcpy(target, base, serverlen);
+                               strlcpy(target + serverlen, data + i, posn - i - 6);
                                if (get_verbosely)
-                                       fprintf(stderr, 
+                                       fprintf(stderr,
                                                "Also look at %s\n", target);
                                newalt = xmalloc(sizeof(*newalt));
-                               newalt->next = alt;
+                               newalt->next = NULL;
                                newalt->base = target;
                                newalt->got_indices = 0;
                                newalt->packs = NULL;
-                               alt = newalt;
-                               ret++;
+                               path = strstr(target, "//");
+                               if (path) {
+                                       path = strchr(path+2, '/');
+                                       if (path)
+                                               newalt->path_len = strlen(path);
+                               }
+
+                               while (tail->next != NULL)
+                                       tail = tail->next;
+                               tail->next = newalt;
                        }
                }
                i = posn + 1;
        }
+
        got_alternates = 1;
-       
-       return ret;
 }
 
+static void fetch_alternates(const char *base)
+{
+       struct buffer buffer;
+       char *url;
+       char *data;
+       struct active_request_slot *slot;
+       struct alternates_request alt_req;
+
+       /* 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 (got_alternates == 0) {
+               step_active_slots();
+       }
+#endif
+
+       /* Nothing to do if they've already been fetched */
+       if (got_alternates == 1)
+               return;
+
+       /* Start the fetch */
+       got_alternates = 0;
+
+       data = xmalloc(4096);
+       buffer.size = 4096;
+       buffer.posn = 0;
+       buffer.buffer = data;
+
+       if (get_verbosely)
+               fprintf(stderr, "Getting alternates list for %s\n", 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 */
+       slot = get_active_slot();
+       slot->callback_func = process_alternates_response;
+       slot->callback_data = &alt_req;
+
+       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);
+
+       alt_req.base = base;
+       alt_req.url = url;
+       alt_req.buffer = &buffer;
+       alt_req.http_specific = 1;
+       alt_req.slot = slot;
+
+       if (start_active_slot(slot))
+               run_active_slot(slot);
+       else
+               got_alternates = -1;
+
+       free(data);
+       free(url);
+}
+
+#ifndef NO_EXPAT
+static void
+xml_start_tag(void *userData, const char *name, const char **atts)
+{
+       struct xml_ctx *ctx = (struct xml_ctx *)userData;
+       const char *c = strchr(name, ':');
+       int new_len;
+
+       if (c == NULL)
+               c = name;
+       else
+               c++;
+
+       new_len = strlen(ctx->name) + strlen(c) + 2;
+
+       if (new_len > ctx->len) {
+               ctx->name = xrealloc(ctx->name, new_len);
+               ctx->len = new_len;
+       }
+       strcat(ctx->name, ".");
+       strcat(ctx->name, c);
+
+       if (ctx->cdata) {
+               free(ctx->cdata);
+               ctx->cdata = NULL;
+       }
+
+       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 == NULL)
+               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;
+       if (ctx->cdata)
+               free(ctx->cdata);
+       ctx->cdata = xmalloc(len + 1);
+       strlcpy(ctx->cdata, s, len + 1);
+}
+
+static int remote_ls(struct alt_base *repo, const char *path, int flags,
+                    void (*userFunc)(struct remote_ls_ctx *ls),
+                    void *userData);
+
+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) {
+                               if (ls->flags & PROCESS_DIRS) {
+                                       ls->userFunc(ls);
+                               }
+                               if (strcmp(ls->dentry_name, ls->path) &&
+                                   ls->flags & RECURSIVE) {
+                                       ls->rc = remote_ls(ls->repo,
+                                                          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) {
+                       ls->dentry_name = xmalloc(strlen(ctx->cdata) -
+                                                 ls->repo->path_len + 1);
+                       strcpy(ls->dentry_name, ctx->cdata + ls->repo->path_len);
+               } else if (!strcmp(ctx->name, DAV_PROPFIND_COLLECTION)) {
+                       ls->dentry_flags |= IS_DIR;
+               }
+       } else if (!strcmp(ctx->name, DAV_PROPFIND_RESP)) {
+               if (ls->dentry_name) {
+                       free(ls->dentry_name);
+               }
+               ls->dentry_name = NULL;
+               ls->dentry_flags = 0;
+       }
+}
+
+static int remote_ls(struct alt_base *repo, const char *path, int flags,
+                    void (*userFunc)(struct remote_ls_ctx *ls),
+                    void *userData)
+{
+       char *url = xmalloc(strlen(repo->base) + strlen(path) + 1);
+       struct active_request_slot *slot;
+       struct slot_results results;
+       struct buffer in_buffer;
+       struct buffer out_buffer;
+       char *in_data;
+       char *out_data;
+       XML_Parser parser = XML_ParserCreate(NULL);
+       enum XML_Status result;
+       struct curl_slist *dav_headers = NULL;
+       struct xml_ctx ctx;
+       struct remote_ls_ctx ls;
+
+       ls.flags = flags;
+       ls.repo = repo;
+       ls.path = strdup(path);
+       ls.dentry_name = NULL;
+       ls.dentry_flags = 0;
+       ls.userData = userData;
+       ls.userFunc = userFunc;
+       ls.rc = 0;
+
+       sprintf(url, "%s%s", repo->base, path);
+
+       out_buffer.size = strlen(PROPFIND_ALL_REQUEST);
+       out_data = xmalloc(out_buffer.size + 1);
+       snprintf(out_data, out_buffer.size + 1, PROPFIND_ALL_REQUEST);
+       out_buffer.posn = 0;
+       out_buffer.buffer = out_data;
+
+       in_buffer.size = 4096;
+       in_data = xmalloc(in_buffer.size);
+       in_buffer.posn = 0;
+       in_buffer.buffer = in_data;
+
+       dav_headers = curl_slist_append(dav_headers, "Depth: 1");
+       dav_headers = curl_slist_append(dav_headers, "Content-Type: text/xml");
+
+       slot = get_active_slot();
+       slot->results = &results;
+       curl_easy_setopt(slot->curl, CURLOPT_INFILE, &out_buffer);
+       curl_easy_setopt(slot->curl, CURLOPT_INFILESIZE, out_buffer.size);
+       curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, fread_buffer);
+       curl_easy_setopt(slot->curl, CURLOPT_FILE, &in_buffer);
+       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
+       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+       curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 1);
+       curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, DAV_PROPFIND);
+       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
+
+       if (start_active_slot(slot)) {
+               run_active_slot(slot);
+               if (results.curl_result == CURLE_OK) {
+                       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.buffer,
+                                          in_buffer.posn, 1);
+                       free(ctx.name);
+
+                       if (result != XML_STATUS_OK) {
+                               ls.rc = error("XML error: %s",
+                                             XML_ErrorString(
+                                                     XML_GetErrorCode(parser)));
+                       }
+               } else {
+                       ls.rc = -1;
+               }
+       } else {
+               ls.rc = error("Unable to start PROPFIND request");
+       }
+
+       free(ls.path);
+       free(url);
+       free(out_data);
+       free(in_buffer.buffer);
+       curl_slist_free_all(dav_headers);
+
+       return ls.rc;
+}
+
+static void process_ls_pack(struct remote_ls_ctx *ls)
+{
+       unsigned char sha1[20];
+
+       if (strlen(ls->dentry_name) == 63 &&
+           !strncmp(ls->dentry_name, "objects/pack/pack-", 18) &&
+           has_extension(ls->dentry_name, ".pack")) {
+               get_sha1_hex(ls->dentry_name + 18, sha1);
+               setup_index(ls->repo, sha1);
+       }
+}
+#endif
+
 static int fetch_indices(struct alt_base *repo)
 {
        unsigned char sha1[20];
@@ -306,6 +885,9 @@ static int fetch_indices(struct alt_base *repo)
        char *data;
        int i = 0;
 
+       struct active_request_slot *slot;
+       struct slot_results results;
+
        if (repo->got_indices)
                return 0;
 
@@ -315,25 +897,49 @@ static int fetch_indices(struct alt_base *repo)
        buffer.buffer = data;
 
        if (get_verbosely)
-               fprintf(stderr, "Getting pack list\n");
-       
+               fprintf(stderr, "Getting pack list for %s\n", repo->base);
+
+#ifndef NO_EXPAT
+       if (remote_ls(repo, "objects/pack/", PROCESS_FILES,
+                     process_ls_pack, NULL) == 0)
+               return 0;
+#endif
+
        url = xmalloc(strlen(repo->base) + 21);
        sprintf(url, "%s/objects/info/packs", repo->base);
 
-       curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
-       curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-       curl_easy_setopt(curl, CURLOPT_URL, url);
-       curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
-       curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_errorstr);
-       
-       if (curl_easy_perform(curl))
-               return error("%s", curl_errorstr);
+       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 (results.http_code == 404 ||
+                           results.curl_result == CURLE_FILE_COULDNT_READ_FILE) {
+                               repo->got_indices = 1;
+                               free(buffer.buffer);
+                               return 0;
+                       } else {
+                               repo->got_indices = 0;
+                               free(buffer.buffer);
+                               return error("%s", curl_errorstr);
+                       }
+               }
+       } else {
+               repo->got_indices = 0;
+               free(buffer.buffer);
+               return error("Unable to start request");
+       }
 
+       data = buffer.buffer;
        while (i < buffer.posn) {
                switch (data[i]) {
                case 'P':
                        i++;
-                       if (i + 52 < buffer.posn &&
+                       if (i + 52 <= buffer.posn &&
                            !strncmp(data + i, " pack-", 6) &&
                            !strncmp(data + i + 46, ".pack\n", 6)) {
                                get_sha1_hex(data + i + 6, sha1);
@@ -342,12 +948,13 @@ static int fetch_indices(struct alt_base *repo)
                                break;
                        }
                default:
-                       while (data[i] != '\n')
+                       while (i < buffer.posn && data[i] != '\n')
                                i++;
                }
                i++;
        }
 
+       free(buffer.buffer);
        repo->got_indices = 1;
        return 0;
 }
@@ -364,7 +971,9 @@ static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
        long prev_posn = 0;
        char range[RANGE_HEADER_SIZE];
        struct curl_slist *range_header = NULL;
-       CURLcode curl_result;
+
+       struct active_request_slot *slot;
+       struct slot_results results;
 
        if (fetch_indices(repo))
                return -1;
@@ -390,11 +999,13 @@ static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
                return error("Unable to open local file %s for pack",
                             filename);
 
-       curl_easy_setopt(curl, CURLOPT_FILE, packfile);
-       curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite);
-       curl_easy_setopt(curl, CURLOPT_URL, url);
-       curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header);
-       curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_errorstr);
+       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, no_pragma_header);
+       slot->local = packfile;
 
        /* If there is data present from a previous transfer attempt,
           resume where it left off */
@@ -406,25 +1017,26 @@ static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
                                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(curl, CURLOPT_HTTPHEADER, range_header);
+               curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
        }
 
-       /* Clear out the Range: header after performing the request, so
-          other curl requests don't inherit inappropriate header data */
-       curl_result = curl_easy_perform(curl);
-       curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_range_header);
-       if (curl_result != 0) {
+       if (start_active_slot(slot)) {
+               run_active_slot(slot);
+               if (results.curl_result != CURLE_OK) {
+                       fclose(packfile);
+                       return error("Unable to get pack file %s\n%s", url,
+                                    curl_errorstr);
+               }
+       } else {
                fclose(packfile);
-               return error("Unable to get pack file %s\n%s", url,
-                            curl_errorstr);
+               return error("Unable to start request");
        }
 
        fclose(packfile);
 
-       ret = relink_or_rename(tmpfile, filename);
+       ret = move_temp_to_file(tmpfile, filename);
        if (ret)
-               return error("unable to write pack filename %s: %s",
-                            filename, strerror(ret));
+               return ret;
 
        lst = &repo->packs;
        while (*lst != target)
@@ -438,199 +1050,185 @@ static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
        return 0;
 }
 
+static void abort_object_request(struct object_request *obj_req)
+{
+       if (obj_req->local >= 0) {
+               close(obj_req->local);
+               obj_req->local = -1;
+       }
+       unlink(obj_req->tmpfile);
+       if (obj_req->slot) {
+               release_active_slot(obj_req->slot);
+               obj_req->slot = NULL;
+       }
+       release_object_request(obj_req);
+}
+
 static int fetch_object(struct alt_base *repo, unsigned char *sha1)
 {
        char *hex = sha1_to_hex(sha1);
-       char *filename = sha1_file_name(sha1);
-       unsigned char real_sha1[20];
-       char tmpfile[PATH_MAX];
-       char prevfile[PATH_MAX];
-       int ret;
-       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;
-       CURLcode curl_result;
-
-       snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
-       snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
-
-       if (unlink(prevfile) && (errno != ENOENT))
-               return error("Failed to unlink %s (%s)",
-                            prevfile, strerror(errno));
-       if (rename(tmpfile, prevfile) && (errno != ENOENT))
-               return error("Failed to rename %s to %s (%s)",
-                            tmpfile, prevfile, strerror(errno));
-
-       local = open(tmpfile, O_WRONLY | O_CREAT | O_EXCL, 0666);
-
-       /* Note: if another instance starts now, it will turn our new
-          tmpfile into its prevfile. */
-
-       if (local < 0)
-               return error("Couldn't create temporary file %s for %s: %s\n",
-                            tmpfile, filename, strerror(errno));
-
-       memset(&stream, 0, sizeof(stream));
-
-       inflateInit(&stream);
-
-       SHA1_Init(&c);
-
-       curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
-       curl_easy_setopt(curl, CURLOPT_FILE, NULL);
-       curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
-       curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header);
-       curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_errorstr);
-
-       url = xmalloc(strlen(repo->base) + 50);
-       strcpy(url, repo->base);
-       posn = url + strlen(repo->base);
-       strcpy(posn, "objects/");
-       posn += 8;
-       memcpy(posn, hex, 2);
-       posn += 2;
-       *(posn++) = '/';
-       strcpy(posn, hex + 2);
+       int ret = 0;
+       struct object_request *obj_req = object_queue_head;
 
-       curl_easy_setopt(curl, CURLOPT_URL, url);
+       while (obj_req != NULL && memcmp(obj_req->sha1, sha1, 20))
+               obj_req = obj_req->next;
+       if (obj_req == NULL)
+               return error("Couldn't find request for %s in the queue", hex);
 
-       /* If a previous temp file is present, process what was already
-          fetched. */
-       prevlocal = open(prevfile, O_RDONLY);
-       if (prevlocal != -1) {
-               do {
-                       prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
-                       if (prev_read>0) {
-                               if (fwrite_sha1_file(prev_buf,
-                                                    1,
-                                                    prev_read,
-                                                    NULL) == prev_read) {
-                                       prev_posn += prev_read;
-                               } else {
-                                       prev_read = -1;
-                               }
-                       }
-               } while (prev_read > 0);
-               close(prevlocal);
+       if (has_sha1_file(obj_req->sha1)) {
+               abort_object_request(obj_req);
+               return 0;
        }
-       unlink(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(&stream, 0, sizeof(stream));
-               inflateInit(&stream);
-               SHA1_Init(&c);
-               if (prev_posn>0) {
-                       prev_posn = 0;
-                       lseek(local, SEEK_SET, 0);
-                       ftruncate(local, 0);
-               }
+#ifdef USE_CURL_MULTI
+       while (obj_req->state == WAITING) {
+               step_active_slots();
        }
+#else
+       start_object_request(obj_req);
+#endif
 
-       /* 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 (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(curl, CURLOPT_HTTPHEADER, range_header);
+       while (obj_req->state == ACTIVE) {
+               run_active_slot(obj_req->slot);
        }
-
-       /* Clear out the Range: header after performing the request, so
-          other curl requests don't inherit inappropriate header data */
-       curl_result = curl_easy_perform(curl);
-       curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_range_header);
-       if (curl_result != 0) {
-               return error("%s", curl_errorstr);
+       if (obj_req->local != -1) {
+               close(obj_req->local); obj_req->local = -1;
        }
 
-       fchmod(local, 0444);
-       close(local);
-       inflateEnd(&stream);
-       SHA1_Final(real_sha1, &c);
-       if (zret != Z_STREAM_END) {
-               unlink(tmpfile);
-               return error("File %s (%s) corrupt\n", hex, url);
+       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 (obj_req->http_code == 404 ||
+                   obj_req->curl_result == CURLE_FILE_COULDNT_READ_FILE)
+                       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) {
+               corrupt_object_found++;
+               ret = error("File %s (%s) corrupt", hex, obj_req->url);
+       } else if (memcmp(obj_req->sha1, obj_req->real_sha1, 20)) {
+               ret = error("File %s has bad hash", hex);
+       } else if (obj_req->rename < 0) {
+               ret = error("unable to write sha1 filename %s",
+                           obj_req->filename);
        }
-       if (memcmp(sha1, real_sha1, 20)) {
-               unlink(tmpfile);
-               return error("File %s has bad hash\n", hex);
-       }
-       ret = relink_or_rename(tmpfile, filename);
-       if (ret)
-               return error("unable to write sha1 filename %s: %s",
-                            filename, strerror(ret));
 
-       pull_say("got %s\n", hex);
-       return 0;
+       release_object_request(obj_req);
+       return ret;
 }
 
 int fetch(unsigned char *sha1)
 {
        struct alt_base *altbase = alt;
+
+       if (!fetch_object(altbase, sha1))
+               return 0;
        while (altbase) {
-               if (!fetch_object(altbase, sha1))
-                       return 0;
                if (!fetch_pack(altbase, sha1))
                        return 0;
-               if (fetch_alternates(altbase->base) > 0) {
-                       altbase = alt;
-                       continue;
-               }
+               fetch_alternates(alt->base);
                altbase = altbase->next;
        }
-       return error("Unable to find %s under %s\n", sha1_to_hex(sha1), 
-                    initial_base);
+       return error("Unable to find %s under %s", sha1_to_hex(sha1),
+                    alt->base);
+}
+
+static inline int needs_quote(int ch)
+{
+       if (((ch >= 'A') && (ch <= 'Z'))
+                       || ((ch >= 'a') && (ch <= 'z'))
+                       || ((ch >= '0') && (ch <= '9'))
+                       || (ch == '/')
+                       || (ch == '-')
+                       || (ch == '.'))
+               return 0;
+       return 1;
+}
+
+static inline int hex(int v)
+{
+       if (v < 10) return '0' + v;
+       else return 'A' + v - 10;
+}
+
+static char *quote_ref_url(const char *base, const char *ref)
+{
+       const char *cp;
+       char *dp, *qref;
+       int len, baselen, ch;
+
+       baselen = strlen(base);
+       len = baselen + 6; /* "refs/" + NUL */
+       for (cp = ref; (ch = *cp) != 0; cp++, len++)
+               if (needs_quote(ch))
+                       len += 2; /* extra two hex plus replacement % */
+       qref = xmalloc(len);
+       memcpy(qref, base, baselen);
+       memcpy(qref + baselen, "refs/", 5);
+       for (cp = ref, dp = qref + baselen + 5; (ch = *cp) != 0; cp++) {
+               if (needs_quote(ch)) {
+                       *dp++ = '%';
+                       *dp++ = hex((ch >> 4) & 0xF);
+                       *dp++ = hex(ch & 0xF);
+               }
+               else
+                       *dp++ = ch;
+       }
+       *dp = 0;
+
+       return qref;
 }
 
 int fetch_ref(char *ref, unsigned char *sha1)
 {
-        char *url, *posn;
+        char *url;
         char hex[42];
         struct buffer buffer;
-       char *base = initial_base;
+       const char *base = alt->base;
+       struct active_request_slot *slot;
+       struct slot_results results;
         buffer.size = 41;
         buffer.posn = 0;
         buffer.buffer = hex;
         hex[41] = '\0';
-        
-        curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
-        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-       curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
-       curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_errorstr);
-
-        url = xmalloc(strlen(base) + 6 + strlen(ref));
-        strcpy(url, base);
-        posn = url + strlen(base);
-        strcpy(posn, "refs/");
-        posn += 5;
-        strcpy(posn, ref);
 
-        curl_easy_setopt(curl, CURLOPT_URL, url);
-
-        if (curl_easy_perform(curl))
-                return error("Couldn't get %s for %s\n%s",
-                            url, ref, curl_errorstr);
+       url = quote_ref_url(base, ref);
+       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)
+                       return error("Couldn't get %s for %s\n%s",
+                                    url, ref, curl_errorstr);
+       } else {
+               return error("Unable to start request");
+       }
 
         hex[40] = '\0';
         get_sha1_hex(hex, sha1);
         return 0;
 }
 
-int main(int argc, char **argv)
+int main(int argc, const char **argv)
 {
-       char *commit_id;
-       char *url;
+       int commits;
+       const char **write_ref = NULL;
+       char **commit_id;
+       const char *url;
+       char *path;
        int arg = 1;
+       int rc = 0;
+
+       setup_ident();
+       setup_git_directory();
+       git_config(git_default_config);
 
        while (arg < argc && argv[arg][0] == '-') {
                if (argv[arg][1] == 't') {
@@ -644,60 +1242,58 @@ int main(int argc, char **argv)
                } else if (argv[arg][1] == 'v') {
                        get_verbosely = 1;
                } else if (argv[arg][1] == 'w') {
-                       write_ref = argv[arg + 1];
+                       write_ref = &argv[arg + 1];
                        arg++;
                } else if (!strcmp(argv[arg], "--recover")) {
                        get_recover = 1;
+               } else if (!strcmp(argv[arg], "--stdin")) {
+                       commits_on_stdin = 1;
                }
                arg++;
        }
-       if (argc < arg + 2) {
-               usage("git-http-fetch [-c] [-t] [-a] [-d] [-v] [--recover] [-w ref] commit-id url");
+       if (argc < arg + 2 - commits_on_stdin) {
+               usage("git-http-fetch [-c] [-t] [-a] [-v] [--recover] [-w ref] [--stdin] commit-id url");
                return 1;
        }
-       commit_id = argv[arg];
-       url = argv[arg + 1];
+       if (commits_on_stdin) {
+               commits = pull_targets_stdin(&commit_id, &write_ref);
+       } else {
+               commit_id = (char **) &argv[arg++];
+               commits = 1;
+       }
+       url = argv[arg];
 
-       curl_global_init(CURL_GLOBAL_ALL);
+       http_init();
 
-       curl = curl_easy_init();
        no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
-       no_range_header = curl_slist_append(no_range_header, "Range:");
-
-       curl_ssl_verify = getenv("GIT_SSL_NO_VERIFY") ? 0 : 1;
-       curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
-#if LIBCURL_VERSION_NUM >= 0x070907
-       curl_easy_setopt(curl, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
-#endif
-
-       if ((ssl_cert = getenv("GIT_SSL_CERT")) != NULL) {
-               curl_easy_setopt(curl, CURLOPT_SSLCERT, ssl_cert);
-       }
-#if LIBCURL_VERSION_NUM >= 0x070902
-       if ((ssl_key = getenv("GIT_SSL_KEY")) != NULL) {
-               curl_easy_setopt(curl, CURLOPT_SSLKEY, ssl_key);
-       }
-#endif
-#if LIBCURL_VERSION_NUM >= 0x070908
-       if ((ssl_capath = getenv("GIT_SSL_CAPATH")) != NULL) {
-               curl_easy_setopt(curl, CURLOPT_CAPATH, ssl_capath);
-       }
-#endif
-       if ((ssl_cainfo = getenv("GIT_SSL_CAINFO")) != NULL) {
-               curl_easy_setopt(curl, CURLOPT_CAINFO, ssl_cainfo);
-       }
 
        alt = xmalloc(sizeof(*alt));
        alt->base = url;
        alt->got_indices = 0;
        alt->packs = NULL;
        alt->next = NULL;
-       initial_base = url;
+       path = strstr(url, "//");
+       if (path) {
+               path = strchr(path+2, '/');
+               if (path)
+                       alt->path_len = strlen(path);
+       }
 
-       if (pull(commit_id))
-               return 1;
+       if (pull(commits, commit_id, write_ref, url))
+               rc = 1;
+
+       http_cleanup();
 
        curl_slist_free_all(no_pragma_header);
-       curl_global_cleanup();
-       return 0;
+
+       if (commits_on_stdin)
+               pull_targets_free(commits, commit_id, write_ref);
+
+       if (corrupt_object_found) {
+               fprintf(stderr,
+"Some loose object were found to be corrupt, but they might be just\n"
+"a false '404 Not Found' error message sent with incorrect HTTP\n"
+"status code.  Suggest running git fsck-objects.\n");
+       }
+       return rc;
 }