Documentation/merge-options.txt: order options in alphabetical groups
[gitweb.git] / http-walker.c
index 0dbad3c888c6c9441af4d9550fd147ecb5b1aaf3..700bc13112d65dfe8cf89af17522e28cf0d76e26 100644 (file)
@@ -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);
@@ -97,166 +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(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) {
+       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(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;
-
-       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;
-       }
-
-       git_inflate_end(&obj_req->stream);
-       git_SHA1_Final(obj_req->real_sha1, &obj_req->c);
-       if (obj_req->zret != Z_STREAM_END) {
-               unlink(obj_req->tmpfile);
+       if (finish_http_object_request(obj_req->req))
                return;
-       }
-       if (hashcmp(obj_req->sha1, obj_req->real_sha1)) {
-               unlink(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));
 }
 
@@ -268,19 +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;
                }
@@ -293,8 +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 {
@@ -304,7 +125,6 @@ static void release_object_request(struct object_request *obj_req)
                        entry->next = entry->next->next;
        }
 
-       free(obj_req->url);
        free(obj_req);
 }
 
@@ -332,28 +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;
        }
 
@@ -363,92 +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);
-                       return error("Unable to get pack index %s\n%s", url,
-                                    curl_errorstr);
-               }
-       } else {
-               fclose(indexfile);
-               return error("Unable to start request");
-       }
-
-       fclose(indexfile);
-
-       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 =
@@ -505,7 +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
@@ -518,7 +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.
                                 *
@@ -547,7 +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, '/');
@@ -591,9 +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();
@@ -613,8 +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;
@@ -641,15 +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;
@@ -657,76 +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;
@@ -741,80 +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);
-                       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);
-               return error("Unable to start request");
+               error("Unable to start request");
+               goto abort;
        }
 
-       target->pack_size = ftell(packfile);
-       fclose(packfile);
-
-       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(obj_req->tmpfile);
-       if (obj_req->slot) {
-               release_active_slot(obj_req->slot);
-               obj_req->slot = NULL;
-       }
        release_object_request(obj_req);
 }
 
@@ -823,6 +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;
@@ -830,45 +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;
 }
@@ -898,10 +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)
@@ -912,8 +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);