root/http-push.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. xml_entities
  2. curl_setup_http_get
  3. curl_setup_http
  4. get_dav_token_headers
  5. process_response
  6. start_fetch_loose
  7. start_mkcol
  8. start_fetch_packed
  9. start_put
  10. start_move
  11. refresh_lock
  12. check_locks
  13. release_request
  14. finish_request
  15. fill_active_slot
  16. add_fetch_request
  17. add_send_request
  18. fetch_indices
  19. one_remote_object
  20. handle_lockprop_ctx
  21. handle_new_lock_ctx
  22. xml_start_tag
  23. xml_end_tag
  24. xml_cdata
  25. lock_remote
  26. unlock_remote
  27. remove_locks
  28. remove_locks_on_signal
  29. get_sha1_hex_from_objpath
  30. process_ls_object
  31. process_ls_ref
  32. handle_remote_ls_ctx
  33. remote_ls
  34. get_remote_object_list
  35. locking_available
  36. add_one_object
  37. process_blob
  38. process_tree
  39. get_delta
  40. update_remote
  41. one_remote_ref
  42. get_dav_remote_heads
  43. add_remote_info_ref
  44. update_remote_info_refs
  45. remote_exists
  46. fetch_symref
  47. verify_merge_base
  48. delete_remote_branch
  49. run_request_queue
  50. main

#include "cache.h"
#include "commit.h"
#include "tag.h"
#include "blob.h"
#include "http.h"
#include "refs.h"
#include "diff.h"
#include "revision.h"
#include "exec_cmd.h"
#include "remote.h"
#include "list-objects.h"
#include "sigchain.h"

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

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

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

#define PREV_BUF_SIZE 4096

/* DAV methods */
#define DAV_LOCK "LOCK"
#define DAV_MKCOL "MKCOL"
#define DAV_MOVE "MOVE"
#define DAV_PROPFIND "PROPFIND"
#define DAV_PUT "PUT"
#define DAV_UNLOCK "UNLOCK"
#define DAV_DELETE "DELETE"

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

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

/* DAV request body templates */
#define PROPFIND_SUPPORTEDLOCK_REQUEST "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:prop xmlns:R=\"%s\">\n<D:supportedlock/>\n</D:prop>\n</D:propfind>"
#define PROPFIND_ALL_REQUEST "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:allprop/>\n</D:propfind>"
#define LOCK_REQUEST "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:lockinfo xmlns:D=\"DAV:\">\n<D:lockscope><D:exclusive/></D:lockscope>\n<D:locktype><D:write/></D:locktype>\n<D:owner>\n<D:href>mailto:%s</D:href>\n</D:owner>\n</D:lockinfo>"

#define LOCK_TIME 600
#define LOCK_REFRESH 30

/* Remember to update object flag allocation in object.h */
#define LOCAL    (1u<<16)
#define REMOTE   (1u<<17)
#define FETCHING (1u<<18)
#define PUSHING  (1u<<19)

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

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

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

static struct object_list *objects;

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

static struct repo *repo;

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

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

static struct transfer_request *request_queue_head;

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

struct remote_lock {
        char *url;
        char *owner;
        char *token;
        char tmpfile_suffix[41];
        time_t start_time;
        long timeout;
        int refreshing;
        struct remote_lock *next;
};

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

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

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

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

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

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

static void curl_setup_http(CURL *curl, const char *url,
                const char *custom_req, struct buffer *buffer,
                curl_write_callback write_fn)
{
        curl_easy_setopt(curl, CURLOPT_PUT, 1);
        curl_easy_setopt(curl, CURLOPT_URL, url);
        curl_easy_setopt(curl, CURLOPT_INFILE, buffer);
        curl_easy_setopt(curl, CURLOPT_INFILESIZE, buffer->buf.len);
        curl_easy_setopt(curl, CURLOPT_READFUNCTION, fread_buffer);
#ifndef NO_CURL_IOCTL
        curl_easy_setopt(curl, CURLOPT_IOCTLFUNCTION, ioctl_buffer);
        curl_easy_setopt(curl, CURLOPT_IOCTLDATA, buffer);
#endif
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_fn);
        curl_easy_setopt(curl, CURLOPT_NOBODY, 0);
        curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, custom_req);
        curl_easy_setopt(curl, CURLOPT_UPLOAD, 1);
}

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

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

        return dav_headers;
}

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

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

        finish_request(request);
}

#ifdef USE_CURL_MULTI

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

        obj_req = new_http_object_request(repo->url, request->obj->sha1);
        if (obj_req == NULL) {
                request->state = ABORTED;
                return;
        }

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

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

static void start_mkcol(struct transfer_request *request)
{
        char *hex = sha1_to_hex(request->obj->sha1);
        struct active_request_slot *slot;

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

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

        if (start_active_slot(slot)) {
                request->slot = slot;
                request->state = RUN_MKCOL;
        } else {
                request->state = ABORTED;
                free(request->url);
                request->url = NULL;
        }
}
#endif

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

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

        target = find_sha1_pack(request->obj->sha1, repo->packs);
        if (!target) {
                fprintf(stderr, "Unable to fetch %s, will not be able to update server info refs\n", sha1_to_hex(request->obj->sha1));
                repo->can_update_info_refs = 0;
                release_request(request);
                return;
        }

        fprintf(stderr, "Fetching pack %s\n", sha1_to_hex(target->sha1));
        fprintf(stderr, " which contains %s\n", sha1_to_hex(request->obj->sha1));

        preq = new_http_pack_request(target, repo->url);
        if (preq == NULL) {
                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, preq->url)) {
                        release_http_pack_request(preq);
                        release_request(request);
                        return;
                }
                check_request = check_request->next;
        }

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

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

static void start_put(struct transfer_request *request)
{
        char *hex = sha1_to_hex(request->obj->sha1);
        struct active_request_slot *slot;
        struct strbuf buf = STRBUF_INIT;
        enum object_type type;
        char hdr[50];
        void *unpacked;
        unsigned long len;
        int hdrlen;
        ssize_t size;
        git_zstream stream;

        unpacked = read_sha1_file(request->obj->sha1, &type, &len);
        hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;

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

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

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

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

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

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

        append_remote_object_url(&buf, repo->url, hex, 0);
        strbuf_add(&buf, request->lock->tmpfile_suffix, 41);
        request->url = strbuf_detach(&buf, NULL);

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

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

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

        slot = get_active_slot();
        slot->callback_func = process_response;
        slot->callback_data = request;
        curl_setup_http_get(slot->curl, request->url, DAV_MOVE);
        dav_headers = curl_slist_append(dav_headers, request->dest);
        dav_headers = curl_slist_append(dav_headers, "Overwrite: T");
        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);

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

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

        lock->refreshing = 1;

        dav_headers = get_dav_token_headers(lock, DAV_HEADER_IF | DAV_HEADER_TIMEOUT);

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

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

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

        return rc;
}

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

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

static void release_request(struct transfer_request *request)
{
        struct transfer_request *entry = request_queue_head;

        if (request == request_queue_head) {
                request_queue_head = request->next;
        } else {
                while (entry->next != NULL && entry->next != request)
                        entry = entry->next;
                if (entry->next == request)
                        entry->next = entry->next->next;
        }

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

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

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

        /* Keep locks active */
        check_locks();

        if (request->headers != NULL)
                curl_slist_free_all(request->headers);

        /* URL is reused for MOVE after PUT */
        if (request->state != RUN_PUT) {
                free(request->url);
                request->url = NULL;
        }

        if (request->state == RUN_MKCOL) {
                if (request->curl_result == CURLE_OK ||
                    request->http_code == 405) {
                        remote_dir_exists[request->obj->sha1[0]] = 1;
                        start_put(request);
                } else {
                        fprintf(stderr, "MKCOL %s failed, aborting (%d/%ld)\n",
                                sha1_to_hex(request->obj->sha1),
                                request->curl_result, request->http_code);
                        request->state = ABORTED;
                        aborted = 1;
                }
        } else if (request->state == RUN_PUT) {
                if (request->curl_result == CURLE_OK) {
                        start_move(request);
                } else {
                        fprintf(stderr, "PUT %s failed, aborting (%d/%ld)\n",
                                sha1_to_hex(request->obj->sha1),
                                request->curl_result, request->http_code);
                        request->state = ABORTED;
                        aborted = 1;
                }
        } else if (request->state == RUN_MOVE) {
                if (request->curl_result == CURLE_OK) {
                        if (push_verbosely)
                                fprintf(stderr, "    sent %s\n",
                                        sha1_to_hex(request->obj->sha1));
                        request->obj->flags |= REMOTE;
                        release_request(request);
                } else {
                        fprintf(stderr, "MOVE %s failed, aborting (%d/%ld)\n",
                                sha1_to_hex(request->obj->sha1),
                                request->curl_result, request->http_code);
                        request->state = ABORTED;
                        aborted = 1;
                }
        } else if (request->state == RUN_FETCH_LOOSE) {
                obj_req = (struct http_object_request *)request->userData;

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

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

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

                        if (preq) {
                                if (finish_http_pack_request(preq) == 0)
                                        fail = 0;
                                release_http_pack_request(preq);
                        }
                }
                if (fail)
                        repo->can_update_info_refs = 0;
                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 || !is_running_queue)
                return 0;

        for (request = request_queue_head; request; request = request->next) {
                if (request->state == NEED_FETCH) {
                        start_fetch_loose(request);
                        return 1;
                } else if (pushing && request->state == NEED_PUSH) {
                        if (remote_dir_exists[request->obj->sha1[0]] == 1) {
                                start_put(request);
                        } else {
                                start_mkcol(request);
                        }
                        return 1;
                }
        }
        return 0;
}
#endif

static void get_remote_object_list(unsigned char parent);

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

        check_locks();

        /*
         * Don't fetch the object if it's known to exist locally
         * or is already in the request queue
         */
        if (remote_dir_exists[obj->sha1[0]] == -1)
                get_remote_object_list(obj->sha1[0]);
        if (obj->flags & (LOCAL | FETCHING))
                return;

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

#ifdef USE_CURL_MULTI
        fill_active_slots();
        step_active_slots();
#endif
}

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

        /* Keep locks active */
        check_locks();

        /*
         * Don't push the object if it's known to exist on the remote
         * or is already in the request queue
         */
        if (remote_dir_exists[obj->sha1[0]] == -1)
                get_remote_object_list(obj->sha1[0]);
        if (obj->flags & (REMOTE | PUSHING))
                return 0;
        target = find_sha1_pack(obj->sha1, repo->packs);
        if (target) {
                obj->flags |= REMOTE;
                return 0;
        }

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

#ifdef USE_CURL_MULTI
        fill_active_slots();
        step_active_slots();
#endif

        return 1;
}

static int fetch_indices(void)
{
        int ret;

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

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

        return ret;
}

static void one_remote_object(const unsigned char *sha1)
{
        struct object *obj;

        obj = lookup_object(sha1);
        if (!obj)
                obj = parse_object(sha1);

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

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

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

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

static void handle_new_lock_ctx(struct xml_ctx *ctx, int tag_closed)
{
        struct remote_lock *lock = (struct remote_lock *)ctx->userData;
        git_SHA_CTX sha_ctx;
        unsigned char lock_token_sha1[20];

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

                        git_SHA1_Init(&sha_ctx);
                        git_SHA1_Update(&sha_ctx, lock->token, strlen(lock->token));
                        git_SHA1_Final(lock_token_sha1, &sha_ctx);

                        lock->tmpfile_suffix[0] = '_';
                        memcpy(lock->tmpfile_suffix + 1, sha1_to_hex(lock_token_sha1), 40);
                }
        }
}

static void one_remote_ref(const char *refname);

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);

        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;
        free(ctx->cdata);
        ctx->cdata = xmemdupz(s, len);
}

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

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

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

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

        sprintf(timeout_header, "Timeout: Second-%ld", timeout);
        dav_headers = curl_slist_append(dav_headers, timeout_header);
        dav_headers = curl_slist_append(dav_headers, "Content-Type: text/xml");

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

        lock = xcalloc(1, sizeof(*lock));
        lock->timeout = -1;

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

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

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

        return lock;
}

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

        dav_headers = get_dav_token_headers(lock, DAV_HEADER_LOCK);

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

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

        curl_slist_free_all(dav_headers);

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

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

        return rc;
}

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

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

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

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

/* extract hex from sharded "xx/x{40}" filename */
static int get_sha1_hex_from_objpath(const char *path, unsigned char *sha1)
{
        char hex[40];

        if (strlen(path) != 41)
                return -1;

        memcpy(hex, path, 2);
        path += 2;
        path++; /* skip '/' */
        memcpy(hex, path, 38);

        return get_sha1_hex(hex, sha1);
}

static void process_ls_object(struct remote_ls_ctx *ls)
{
        unsigned int *parent = (unsigned int *)ls->userData;
        const char *path = ls->dentry_name;
        unsigned char sha1[20];

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

        if (!skip_prefix(path, "objects/", &path) ||
            get_sha1_hex_from_objpath(path, sha1))
                return;

        one_remote_object(sha1);
}

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

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

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

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

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

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

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

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

        strbuf_addf(&out_buffer.buf, PROPFIND_ALL_REQUEST);

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        return lock_flags;
}

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

static struct object_list **process_blob(struct blob *blob,
                                         struct object_list **p,
                                         struct name_path *path,
                                         const char *name)
{
        struct object *obj = &blob->object;

        obj->flags |= LOCAL;

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

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

static struct object_list **process_tree(struct tree *tree,
                                         struct object_list **p,
                                         struct name_path *path,
                                         const char *name)
{
        struct object *obj = &tree->object;
        struct tree_desc desc;
        struct name_entry entry;
        struct name_path me;

        obj->flags |= LOCAL;

        if (obj->flags & (UNINTERESTING | SEEN))
                return p;
        if (parse_tree(tree) < 0)
                die("bad tree object %s", sha1_to_hex(obj->sha1));

        obj->flags |= SEEN;
        name = xstrdup(name);
        p = add_one_object(obj, p);
        me.up = path;
        me.elem = name;
        me.elem_len = strlen(name);

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

        while (tree_entry(&desc, &entry))
                switch (object_type(entry.mode)) {
                case OBJ_TREE:
                        p = process_tree(lookup_tree(entry.sha1), p, &me, name);
                        break;
                case OBJ_BLOB:
                        p = process_blob(lookup_blob(entry.sha1), p, &me, name);
                        break;
                default:
                        /* Subproject commit - not in this repository */
                        break;
                }

        free_tree_buffer(tree);
        return p;
}

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

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

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

                if (obj->flags & (UNINTERESTING | SEEN))
                        continue;
                if (obj->type == OBJ_TAG) {
                        obj->flags |= SEEN;
                        p = add_one_object(obj, p);
                        continue;
                }
                if (obj->type == OBJ_TREE) {
                        p = process_tree((struct tree *)obj, p, NULL, name);
                        continue;
                }
                if (obj->type == OBJ_BLOB) {
                        p = process_blob((struct blob *)obj, p, NULL, name);
                        continue;
                }
                die("unknown pending object %s (%s)", sha1_to_hex(obj->sha1), name);
        }

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

        return count;
}

static int update_remote(unsigned char *sha1, struct remote_lock *lock)
{
        struct active_request_slot *slot;
        struct slot_results results;
        struct buffer out_buffer = { STRBUF_INIT, 0 };
        struct curl_slist *dav_headers;

        dav_headers = get_dav_token_headers(lock, DAV_HEADER_IF);

        strbuf_addf(&out_buffer.buf, "%s\n", sha1_to_hex(sha1));

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

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

        return 1;
}

static struct ref *remote_refs;

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

        ref = alloc_ref(refname);

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

        /*
         * Fetch a copy of the object if it doesn't exist locally - it
         * may be required for updating server info later.
         */
        if (repo->can_update_info_refs && !has_sha1_file(ref->old_sha1)) {
                obj = lookup_unknown_object(ref->old_sha1);
                if (obj) {
                        fprintf(stderr, "  fetch %s for %s\n",
                                sha1_to_hex(ref->old_sha1), refname);
                        add_fetch_request(obj);
                }
        }

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

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

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

        ref = alloc_ref(ls->dentry_name);

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

        o = parse_object(ref->old_sha1);
        if (!o) {
                fprintf(stderr,
                        "Unable to parse object %s for remote ref %s\n",
                        sha1_to_hex(ref->old_sha1), ls->dentry_name);
                aborted = 1;
                free(ref);
                return;
        }

        len = strlen(ls->dentry_name) + 42;
        ref_info = xcalloc(len + 1, 1);
        sprintf(ref_info, "%s   %s\n",
                sha1_to_hex(ref->old_sha1), ls->dentry_name);
        fwrite_buffer(ref_info, 1, len, buf);
        free(ref_info);

        if (o->type == OBJ_TAG) {
                o = deref_tag(o, ls->dentry_name, 0);
                if (o) {
                        len = strlen(ls->dentry_name) + 45;
                        ref_info = xcalloc(len + 1, 1);
                        sprintf(ref_info, "%s   %s^{}\n",
                                sha1_to_hex(o->sha1), ls->dentry_name);
                        fwrite_buffer(ref_info, 1, len, buf);
                        free(ref_info);
                }
        }
        free(ref);
}

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

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

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

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

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


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

static void fetch_symref(const char *path, char **symref, unsigned char *sha1)
{
        char *url = xstrfmt("%s%s", repo->url, path);
        struct strbuf buffer = STRBUF_INIT;
        const char *name;

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

        free(*symref);
        *symref = NULL;
        hashclr(sha1);

        if (buffer.len == 0)
                return;

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

        /* If it's a symref, set the refname; otherwise try for a sha1 */
        if (skip_prefix(buffer.buf, "ref: ", &name)) {
                *symref = xmemdupz(name, buffer.len - (name - buffer.buf));
        } else {
                get_sha1_hex(buffer.buf, sha1);
        }

        strbuf_release(&buffer);
}

static int verify_merge_base(unsigned char *head_sha1, struct ref *remote)
{
        struct commit *head = lookup_commit_or_die(head_sha1, "HEAD");
        struct commit *branch = lookup_commit_or_die(remote->old_sha1, remote->name);

        return in_merge_bases(branch, head);
}

static int delete_remote_branch(const char *pattern, int force)
{
        struct ref *refs = remote_refs;
        struct ref *remote_ref = NULL;
        unsigned char head_sha1[20];
        char *symref = NULL;
        int match;
        int patlen = strlen(pattern);
        int i;
        struct active_request_slot *slot;
        struct slot_results results;
        char *url;

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

        /*
         * Remote HEAD must be a symref (not exactly foolproof; a remote
         * symlink to a symref will look like a symref)
         */
        fetch_symref("HEAD", &symref, head_sha1);
        if (!symref)
                return error("Remote HEAD is not a symref");

        /* Remote branch must not be the remote HEAD */
        for (i = 0; symref && i < MAXDEPTH; i++) {
                if (!strcmp(remote_ref->name, symref))
                        return error("Remote branch %s is the current HEAD",
                                     remote_ref->name);
                fetch_symref(symref, &symref, head_sha1);
        }

        /* Run extra sanity checks if delete is not forced */
        if (!force) {
                /* Remote HEAD must resolve to a known object */
                if (symref)
                        return error("Remote HEAD symrefs too deep");
                if (is_null_sha1(head_sha1))
                        return error("Unable to resolve remote HEAD");
                if (!has_sha1_file(head_sha1))
                        return error("Remote HEAD resolves to object %s\nwhich does not exist locally, perhaps you need to fetch?", sha1_to_hex(head_sha1));

                /* Remote branch must resolve to a known object */
                if (is_null_sha1(remote_ref->old_sha1))
                        return error("Unable to resolve remote branch %s",
                                     remote_ref->name);
                if (!has_sha1_file(remote_ref->old_sha1))
                        return error("Remote branch %s resolves to object %s\nwhich does not exist locally, perhaps you need to fetch?", remote_ref->name, sha1_to_hex(remote_ref->old_sha1));

                /* Remote branch must be an ancestor of remote HEAD */
                if (!verify_merge_base(head_sha1, remote_ref)) {
                        return error("The branch '%s' is not an ancestor "
                                     "of your current HEAD.\n"
                                     "If you are sure you want to delete it,"
                                     " run:\n\t'git http-push -D %s %s'",
                                     remote_ref->name, repo->url, pattern);
                }
        }

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

        return 0;
}

static void run_request_queue(void)
{
#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;
        struct transfer_request *next_request;
        int nr_refspec = 0;
        char **refspec = NULL;
        struct remote_lock *ref_lock = NULL;
        struct remote_lock *info_ref_lock = NULL;
        struct rev_info revs;
        int delete_branch = 0;
        int force_delete = 0;
        int objects_to_send;
        int rc = 0;
        int i;
        int new_refs;
        struct ref *ref, *local_refs;

        git_setup_gettext();

        git_extract_argv0_path(argv[0]);

        repo = xcalloc(1, sizeof(*repo));

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

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

#ifndef USE_CURL_MULTI
        die("git-push is not available for http/https repository when not compiled with USE_CURL_MULTI");
#endif

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

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

        setup_git_directory();

        memset(remote_dir_exists, -1, 256);

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

#ifdef USE_CURL_MULTI
        is_running_queue = 0;
#endif

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

        sigchain_push_common(remove_locks_on_signal);

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

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

        /* Remove a remote branch if -d or -D was specified */
        if (delete_branch) {
                if (delete_remote_branch(refspec[0], force_delete) == -1) {
                        fprintf(stderr, "Unable to delete remote branch %s\n",
                                refspec[0]);
                        if (helper_status)
                                printf("error %s cannot remove\n", refspec[0]);
                }
                goto cleanup;
        }

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

        new_refs = 0;
        for (ref = remote_refs; ref; ref = ref->next) {
                char old_hex[60], *new_hex;
                const char *commit_argv[5];
                int commit_argc;
                char *new_sha1_hex, *old_sha1_hex;

                if (!ref->peer_ref)
                        continue;

                if (is_null_sha1(ref->peer_ref->new_sha1)) {
                        if (delete_remote_branch(ref->name, 1) == -1) {
                                error("Could not remove %s", ref->name);
                                if (helper_status)
                                        printf("error %s cannot remove\n", ref->name);
                                rc = -4;
                        }
                        else if (helper_status)
                                printf("ok %s\n", ref->name);
                        new_refs++;
                        continue;
                }

                if (!hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
                        if (push_verbosely)
                                fprintf(stderr, "'%s': up-to-date\n", ref->name);
                        if (helper_status)
                                printf("ok %s up to date\n", ref->name);
                        continue;
                }

                if (!force_all &&
                    !is_null_sha1(ref->old_sha1) &&
                    !ref->force) {
                        if (!has_sha1_file(ref->old_sha1) ||
                            !ref_newer(ref->peer_ref->new_sha1,
                                       ref->old_sha1)) {
                                /*
                                 * We do not have the remote ref, or
                                 * we know that the remote ref is not
                                 * an ancestor of what we are trying to
                                 * push.  Either way this can be losing
                                 * commits at the remote end and likely
                                 * we were not up to date to begin with.
                                 */
                                error("remote '%s' is not an ancestor of\n"
                                      "local '%s'.\n"
                                      "Maybe you are not up-to-date and "
                                      "need to pull first?",
                                      ref->name,
                                      ref->peer_ref->name);
                                if (helper_status)
                                        printf("error %s non-fast forward\n", ref->name);
                                rc = -2;
                                continue;
                        }
                }
                hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
                new_refs++;
                strcpy(old_hex, sha1_to_hex(ref->old_sha1));
                new_hex = sha1_to_hex(ref->new_sha1);

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

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

                /* Set up revision info for this refspec */
                commit_argc = 3;
                new_sha1_hex = xstrdup(sha1_to_hex(ref->new_sha1));
                old_sha1_hex = NULL;
                commit_argv[1] = "--objects";
                commit_argv[2] = new_sha1_hex;
                if (!push_all && !is_null_sha1(ref->old_sha1)) {
                        old_sha1_hex = xmalloc(42);
                        sprintf(old_sha1_hex, "^%s",
                                sha1_to_hex(ref->old_sha1));
                        commit_argv[3] = old_sha1_hex;
                        commit_argc++;
                }
                commit_argv[commit_argc] = NULL;
                init_revisions(&revs, setup_git_directory());
                setup_revisions(commit_argc, commit_argv, &revs, NULL);
                revs.edge_hint = 0; /* just in case */
                free(new_sha1_hex);
                if (old_sha1_hex) {
                        free(old_sha1_hex);
                        commit_argv[1] = NULL;
                }

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

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

                run_request_queue();

                /* Update the remote branch if all went well */
                if (aborted || !update_remote(ref->new_sha1, ref_lock))
                        rc = 1;

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

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

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

        http_cleanup();

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

        return rc;
}

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