Adding upstream version 1:2.43.0.upstream/1%2.43.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 935 insertions, 0 deletions

diff --git a/bundle-uri.c b/bundle-uri.c
new file mode 100644
index 0000000..8492fff
--- /dev/null
+++ b/bundle-uri.c
@@ -0,0 +1,935 @@
+#include "git-compat-util.h"
+#include "bundle-uri.h"
+#include "bundle.h"
+#include "copy.h"
+#include "environment.h"
+#include "gettext.h"
+#include "object-store-ll.h"
+#include "refs.h"
+#include "run-command.h"
+#include "hashmap.h"
+#include "pkt-line.h"
+#include "config.h"
+#include "remote.h"
+
+static struct {
+	enum bundle_list_heuristic heuristic;
+	const char *name;
+} heuristics[BUNDLE_HEURISTIC__COUNT] = {
+	{ BUNDLE_HEURISTIC_NONE, ""},
+	{ BUNDLE_HEURISTIC_CREATIONTOKEN, "creationToken" },
+};
+
+static int compare_bundles(const void *hashmap_cmp_fn_data UNUSED,
+			   const struct hashmap_entry *he1,
+			   const struct hashmap_entry *he2,
+			   const void *id)
+{
+	const struct remote_bundle_info *e1 =
+		container_of(he1, const struct remote_bundle_info, ent);
+	const struct remote_bundle_info *e2 =
+		container_of(he2, const struct remote_bundle_info, ent);
+
+	return strcmp(e1->id, id ? (const char *)id : e2->id);
+}
+
+void init_bundle_list(struct bundle_list *list)
+{
+	memset(list, 0, sizeof(*list));
+
+	/* Implied defaults. */
+	list->mode = BUNDLE_MODE_ALL;
+	list->version = 1;
+
+	hashmap_init(&list->bundles, compare_bundles, NULL, 0);
+}
+
+static int clear_remote_bundle_info(struct remote_bundle_info *bundle,
+				    void *data UNUSED)
+{
+	FREE_AND_NULL(bundle->id);
+	FREE_AND_NULL(bundle->uri);
+	FREE_AND_NULL(bundle->file);
+	bundle->unbundled = 0;
+	return 0;
+}
+
+void clear_bundle_list(struct bundle_list *list)
+{
+	if (!list)
+		return;
+
+	for_all_bundles_in_list(list, clear_remote_bundle_info, NULL);
+	hashmap_clear_and_free(&list->bundles, struct remote_bundle_info, ent);
+	free(list->baseURI);
+}
+
+int for_all_bundles_in_list(struct bundle_list *list,
+			    bundle_iterator iter,
+			    void *data)
+{
+	struct remote_bundle_info *info;
+	struct hashmap_iter i;
+
+	hashmap_for_each_entry(&list->bundles, &i, info, ent) {
+		int result = iter(info, data);
+
+		if (result)
+			return result;
+	}
+
+	return 0;
+}
+
+static int summarize_bundle(struct remote_bundle_info *info, void *data)
+{
+	FILE *fp = data;
+	fprintf(fp, "[bundle \"%s\"]\n", info->id);
+	fprintf(fp, "\turi = %s\n", info->uri);
+
+	if (info->creationToken)
+		fprintf(fp, "\tcreationToken = %"PRIu64"\n", info->creationToken);
+	return 0;
+}
+
+void print_bundle_list(FILE *fp, struct bundle_list *list)
+{
+	const char *mode;
+
+	switch (list->mode) {
+	case BUNDLE_MODE_ALL:
+		mode = "all";
+		break;
+
+	case BUNDLE_MODE_ANY:
+		mode = "any";
+		break;
+
+	case BUNDLE_MODE_NONE:
+	default:
+		mode = "<unknown>";
+	}
+
+	fprintf(fp, "[bundle]\n");
+	fprintf(fp, "\tversion = %d\n", list->version);
+	fprintf(fp, "\tmode = %s\n", mode);
+
+	if (list->heuristic) {
+		int i;
+		for (i = 0; i < BUNDLE_HEURISTIC__COUNT; i++) {
+			if (heuristics[i].heuristic == list->heuristic) {
+				printf("\theuristic = %s\n",
+				       heuristics[list->heuristic].name);
+				break;
+			}
+		}
+	}
+
+	for_all_bundles_in_list(list, summarize_bundle, fp);
+}
+
+/**
+ * Given a key-value pair, update the state of the given bundle list.
+ * Returns 0 if the key-value pair is understood. Returns -1 if the key
+ * is not understood or the value is malformed.
+ */
+static int bundle_list_update(const char *key, const char *value,
+			      struct bundle_list *list)
+{
+	struct strbuf id = STRBUF_INIT;
+	struct remote_bundle_info lookup = REMOTE_BUNDLE_INFO_INIT;
+	struct remote_bundle_info *bundle;
+	const char *subsection, *subkey;
+	size_t subsection_len;
+
+	if (parse_config_key(key, "bundle", &subsection, &subsection_len, &subkey))
+		return -1;
+
+	if (!subsection_len) {
+		if (!strcmp(subkey, "version")) {
+			int version;
+			if (!git_parse_int(value, &version))
+				return -1;
+			if (version != 1)
+				return -1;
+
+			list->version = version;
+			return 0;
+		}
+
+		if (!strcmp(subkey, "mode")) {
+			if (!strcmp(value, "all"))
+				list->mode = BUNDLE_MODE_ALL;
+			else if (!strcmp(value, "any"))
+				list->mode = BUNDLE_MODE_ANY;
+			else
+				return -1;
+			return 0;
+		}
+
+		if (!strcmp(subkey, "heuristic")) {
+			int i;
+			for (i = 0; i < BUNDLE_HEURISTIC__COUNT; i++) {
+				if (heuristics[i].heuristic &&
+				    heuristics[i].name &&
+				    !strcmp(value, heuristics[i].name)) {
+					list->heuristic = heuristics[i].heuristic;
+					return 0;
+				}
+			}
+
+			/* Ignore unknown heuristics. */
+			return 0;
+		}
+
+		/* Ignore other unknown global keys. */
+		return 0;
+	}
+
+	strbuf_add(&id, subsection, subsection_len);
+
+	/*
+	 * Check for an existing bundle with this <id>, or create one
+	 * if necessary.
+	 */
+	lookup.id = id.buf;
+	hashmap_entry_init(&lookup.ent, strhash(lookup.id));
+	if (!(bundle = hashmap_get_entry(&list->bundles, &lookup, ent, NULL))) {
+		CALLOC_ARRAY(bundle, 1);
+		bundle->id = strbuf_detach(&id, NULL);
+		hashmap_entry_init(&bundle->ent, strhash(bundle->id));
+		hashmap_add(&list->bundles, &bundle->ent);
+	}
+	strbuf_release(&id);
+
+	if (!strcmp(subkey, "uri")) {
+		if (bundle->uri)
+			return -1;
+		bundle->uri = relative_url(list->baseURI, value, NULL);
+		return 0;
+	}
+
+	if (!strcmp(subkey, "creationtoken")) {
+		if (sscanf(value, "%"PRIu64, &bundle->creationToken) != 1)
+			warning(_("could not parse bundle list key %s with value '%s'"),
+				"creationToken", value);
+		return 0;
+	}
+
+	/*
+	 * At this point, we ignore any information that we don't
+	 * understand, assuming it to be hints for a heuristic the client
+	 * does not currently understand.
+	 */
+	return 0;
+}
+
+static int config_to_bundle_list(const char *key, const char *value,
+				 const struct config_context *ctx UNUSED,
+				 void *data)
+{
+	struct bundle_list *list = data;
+	return bundle_list_update(key, value, list);
+}
+
+int bundle_uri_parse_config_format(const char *uri,
+				   const char *filename,
+				   struct bundle_list *list)
+{
+	int result;
+	struct config_options opts = {
+		.error_action = CONFIG_ERROR_ERROR,
+	};
+
+	if (!list->baseURI) {
+		struct strbuf baseURI = STRBUF_INIT;
+		strbuf_addstr(&baseURI, uri);
+
+		/*
+		 * If the URI does not end with a trailing slash, then
+		 * remove the filename portion of the path. This is
+		 * important for relative URIs.
+		 */
+		strbuf_strip_file_from_path(&baseURI);
+		list->baseURI = strbuf_detach(&baseURI, NULL);
+	}
+	result = git_config_from_file_with_options(config_to_bundle_list,
+						   filename, list,
+						   CONFIG_SCOPE_UNKNOWN,
+						   &opts);
+
+	if (!result && list->mode == BUNDLE_MODE_NONE) {
+		warning(_("bundle list at '%s' has no mode"), uri);
+		result = 1;
+	}
+
+	return result;
+}
+
+static char *find_temp_filename(void)
+{
+	int fd;
+	struct strbuf name = STRBUF_INIT;
+	/*
+	 * Find a temporary filename that is available. This is briefly
+	 * racy, but unlikely to collide.
+	 */
+	fd = odb_mkstemp(&name, "bundles/tmp_uri_XXXXXX");
+	if (fd < 0) {
+		warning(_("failed to create temporary file"));
+		return NULL;
+	}
+
+	close(fd);
+	unlink(name.buf);
+	return strbuf_detach(&name, NULL);
+}
+
+static int download_https_uri_to_file(const char *file, const char *uri)
+{
+	int result = 0;
+	struct child_process cp = CHILD_PROCESS_INIT;
+	FILE *child_in = NULL, *child_out = NULL;
+	struct strbuf line = STRBUF_INIT;
+	int found_get = 0;
+
+	strvec_pushl(&cp.args, "git-remote-https", uri, NULL);
+	cp.err = -1;
+	cp.in = -1;
+	cp.out = -1;
+
+	if (start_command(&cp))
+		return 1;
+
+	child_in = fdopen(cp.in, "w");
+	if (!child_in) {
+		result = 1;
+		goto cleanup;
+	}
+
+	child_out = fdopen(cp.out, "r");
+	if (!child_out) {
+		result = 1;
+		goto cleanup;
+	}
+
+	fprintf(child_in, "capabilities\n");
+	fflush(child_in);
+
+	while (!strbuf_getline(&line, child_out)) {
+		if (!line.len)
+			break;
+		if (!strcmp(line.buf, "get"))
+			found_get = 1;
+	}
+	strbuf_release(&line);
+
+	if (!found_get) {
+		result = error(_("insufficient capabilities"));
+		goto cleanup;
+	}
+
+	fprintf(child_in, "get %s %s\n\n", uri, file);
+
+cleanup:
+	if (child_in)
+		fclose(child_in);
+	if (finish_command(&cp))
+		return 1;
+	if (child_out)
+		fclose(child_out);
+	return result;
+}
+
+static int copy_uri_to_file(const char *filename, const char *uri)
+{
+	const char *out;
+
+	if (starts_with(uri, "https:") ||
+	    starts_with(uri, "http:"))
+		return download_https_uri_to_file(filename, uri);
+
+	if (skip_prefix(uri, "file://", &out))
+		uri = out;
+
+	/* Copy as a file */
+	return copy_file(filename, uri, 0);
+}
+
+static int unbundle_from_file(struct repository *r, const char *file)
+{
+	int result = 0;
+	int bundle_fd;
+	struct bundle_header header = BUNDLE_HEADER_INIT;
+	struct string_list_item *refname;
+	struct strbuf bundle_ref = STRBUF_INIT;
+	size_t bundle_prefix_len;
+
+	if ((bundle_fd = read_bundle_header(file, &header)) < 0)
+		return 1;
+
+	/*
+	 * Skip the reachability walk here, since we will be adding
+	 * a reachable ref pointing to the new tips, which will reach
+	 * the prerequisite commits.
+	 */
+	if ((result = unbundle(r, &header, bundle_fd, NULL,
+			       VERIFY_BUNDLE_QUIET)))
+		return 1;
+
+	/*
+	 * Convert all refs/heads/ from the bundle into refs/bundles/
+	 * in the local repository.
+	 */
+	strbuf_addstr(&bundle_ref, "refs/bundles/");
+	bundle_prefix_len = bundle_ref.len;
+
+	for_each_string_list_item(refname, &header.references) {
+		struct object_id *oid = refname->util;
+		struct object_id old_oid;
+		const char *branch_name;
+		int has_old;
+
+		if (!skip_prefix(refname->string, "refs/heads/", &branch_name))
+			continue;
+
+		strbuf_setlen(&bundle_ref, bundle_prefix_len);
+		strbuf_addstr(&bundle_ref, branch_name);
+
+		has_old = !read_ref(bundle_ref.buf, &old_oid);
+		update_ref("fetched bundle", bundle_ref.buf, oid,
+			   has_old ? &old_oid : NULL,
+			   REF_SKIP_OID_VERIFICATION,
+			   UPDATE_REFS_MSG_ON_ERR);
+	}
+
+	bundle_header_release(&header);
+	return result;
+}
+
+struct bundle_list_context {
+	struct repository *r;
+	struct bundle_list *list;
+	enum bundle_list_mode mode;
+	int count;
+	int depth;
+};
+
+/*
+ * This early definition is necessary because we use indirect recursion:
+ *
+ * While iterating through a bundle list that was downloaded as part
+ * of fetch_bundle_uri_internal(), iterator methods eventually call it
+ * again, but with depth + 1.
+ */
+static int fetch_bundle_uri_internal(struct repository *r,
+				     struct remote_bundle_info *bundle,
+				     int depth,
+				     struct bundle_list *list);
+
+static int download_bundle_to_file(struct remote_bundle_info *bundle, void *data)
+{
+	int res;
+	struct bundle_list_context *ctx = data;
+
+	if (ctx->mode == BUNDLE_MODE_ANY && ctx->count)
+		return 0;
+
+	res = fetch_bundle_uri_internal(ctx->r, bundle, ctx->depth + 1, ctx->list);
+
+	/*
+	 * Only increment count if the download succeeded. If our mode is
+	 * BUNDLE_MODE_ANY, then we will want to try other URIs in the
+	 * list in case they work instead.
+	 */
+	if (!res)
+		ctx->count++;
+
+	/*
+	 * To be opportunistic as possible, we continue iterating and
+	 * download as many bundles as we can, so we can apply the ones
+	 * that work, even in BUNDLE_MODE_ALL mode.
+	 */
+	return 0;
+}
+
+struct bundles_for_sorting {
+	struct remote_bundle_info **items;
+	size_t alloc;
+	size_t nr;
+};
+
+static int append_bundle(struct remote_bundle_info *bundle, void *data)
+{
+	struct bundles_for_sorting *list = data;
+	list->items[list->nr++] = bundle;
+	return 0;
+}
+
+/**
+ * For use in QSORT() to get a list sorted by creationToken
+ * in decreasing order.
+ */
+static int compare_creation_token_decreasing(const void *va, const void *vb)
+{
+	const struct remote_bundle_info * const *a = va;
+	const struct remote_bundle_info * const *b = vb;
+
+	if ((*a)->creationToken > (*b)->creationToken)
+		return -1;
+	if ((*a)->creationToken < (*b)->creationToken)
+		return 1;
+	return 0;
+}
+
+static int fetch_bundles_by_token(struct repository *r,
+				  struct bundle_list *list)
+{
+	int cur;
+	int move_direction = 0;
+	const char *creationTokenStr;
+	uint64_t maxCreationToken = 0, newMaxCreationToken = 0;
+	struct bundle_list_context ctx = {
+		.r = r,
+		.list = list,
+		.mode = list->mode,
+	};
+	struct bundles_for_sorting bundles = {
+		.alloc = hashmap_get_size(&list->bundles),
+	};
+
+	ALLOC_ARRAY(bundles.items, bundles.alloc);
+
+	for_all_bundles_in_list(list, append_bundle, &bundles);
+
+	if (!bundles.nr) {
+		free(bundles.items);
+		return 0;
+	}
+
+	QSORT(bundles.items, bundles.nr, compare_creation_token_decreasing);
+
+	/*
+	 * If fetch.bundleCreationToken exists, parses to a uint64t, and
+	 * is not strictly smaller than the maximum creation token in the
+	 * bundle list, then do not download any bundles.
+	 */
+	if (!repo_config_get_value(r,
+				   "fetch.bundlecreationtoken",
+				   &creationTokenStr) &&
+	    sscanf(creationTokenStr, "%"PRIu64, &maxCreationToken) == 1 &&
+	    bundles.items[0]->creationToken <= maxCreationToken) {
+		free(bundles.items);
+		return 0;
+	}
+
+	/*
+	 * Attempt to download and unbundle the minimum number of bundles by
+	 * creationToken in decreasing order. If we fail to unbundle (after
+	 * a successful download) then move to the next non-downloaded bundle
+	 * and attempt downloading. Once we succeed in applying a bundle,
+	 * move to the previous unapplied bundle and attempt to unbundle it
+	 * again.
+	 *
+	 * In the case of a fresh clone, we will likely download all of the
+	 * bundles before successfully unbundling the oldest one, then the
+	 * rest of the bundles unbundle successfully in increasing order
+	 * of creationToken.
+	 *
+	 * If there are existing objects, then this process may terminate
+	 * early when all required commits from "new" bundles exist in the
+	 * repo's object store.
+	 */
+	cur = 0;
+	while (cur >= 0 && cur < bundles.nr) {
+		struct remote_bundle_info *bundle = bundles.items[cur];
+
+		/*
+		 * If we need to dig into bundles below the previous
+		 * creation token value, then likely we are in an erroneous
+		 * state due to missing or invalid bundles. Halt the process
+		 * instead of continuing to download extra data.
+		 */
+		if (bundle->creationToken <= maxCreationToken)
+			break;
+
+		if (!bundle->file) {
+			/*
+			 * Not downloaded yet. Try downloading.
+			 *
+			 * Note that bundle->file is non-NULL if a download
+			 * was attempted, even if it failed to download.
+			 */
+			if (fetch_bundle_uri_internal(ctx.r, bundle, ctx.depth + 1, ctx.list)) {
+				/* Mark as unbundled so we do not retry. */
+				bundle->unbundled = 1;
+
+				/* Try looking deeper in the list. */
+				move_direction = 1;
+				goto move;
+			}
+
+			/* We expect bundles when using creationTokens. */
+			if (!is_bundle(bundle->file, 1)) {
+				warning(_("file downloaded from '%s' is not a bundle"),
+					bundle->uri);
+				break;
+			}
+		}
+
+		if (bundle->file && !bundle->unbundled) {
+			/*
+			 * This was downloaded, but not successfully
+			 * unbundled. Try unbundling again.
+			 */
+			if (unbundle_from_file(ctx.r, bundle->file)) {
+				/* Try looking deeper in the list. */
+				move_direction = 1;
+			} else {
+				/*
+				 * Succeeded in unbundle. Retry bundles
+				 * that previously failed to unbundle.
+				 */
+				move_direction = -1;
+				bundle->unbundled = 1;
+
+				if (bundle->creationToken > newMaxCreationToken)
+					newMaxCreationToken = bundle->creationToken;
+			}
+		}
+
+		/*
+		 * Else case: downloaded and unbundled successfully.
+		 * Skip this by moving in the same direction as the
+		 * previous step.
+		 */
+
+move:
+		/* Move in the specified direction and repeat. */
+		cur += move_direction;
+	}
+
+	/*
+	 * We succeed if the loop terminates because 'cur' drops below
+	 * zero. The other case is that we terminate because 'cur'
+	 * reaches the end of the list, so we have a failure no matter
+	 * which bundles we apply from the list.
+	 */
+	if (cur < 0) {
+		struct strbuf value = STRBUF_INIT;
+		strbuf_addf(&value, "%"PRIu64"", newMaxCreationToken);
+		if (repo_config_set_multivar_gently(ctx.r,
+						    "fetch.bundleCreationToken",
+						    value.buf, NULL, 0))
+			warning(_("failed to store maximum creation token"));
+
+		strbuf_release(&value);
+	}
+
+	free(bundles.items);
+	return cur >= 0;
+}
+
+static int download_bundle_list(struct repository *r,
+				struct bundle_list *local_list,
+				struct bundle_list *global_list,
+				int depth)
+{
+	struct bundle_list_context ctx = {
+		.r = r,
+		.list = global_list,
+		.depth = depth + 1,
+		.mode = local_list->mode,
+	};
+
+	return for_all_bundles_in_list(local_list, download_bundle_to_file, &ctx);
+}
+
+static int fetch_bundle_list_in_config_format(struct repository *r,
+					      struct bundle_list *global_list,
+					      struct remote_bundle_info *bundle,
+					      int depth)
+{
+	int result;
+	struct bundle_list list_from_bundle;
+
+	init_bundle_list(&list_from_bundle);
+
+	if ((result = bundle_uri_parse_config_format(bundle->uri,
+						     bundle->file,
+						     &list_from_bundle)))
+		goto cleanup;
+
+	if (list_from_bundle.mode == BUNDLE_MODE_NONE) {
+		warning(_("unrecognized bundle mode from URI '%s'"),
+			bundle->uri);
+		result = -1;
+		goto cleanup;
+	}
+
+	/*
+	 * If this list uses the creationToken heuristic, then the URIs
+	 * it advertises are expected to be bundles, not nested lists.
+	 * We can drop 'global_list' and 'depth'.
+	 */
+	if (list_from_bundle.heuristic == BUNDLE_HEURISTIC_CREATIONTOKEN) {
+		result = fetch_bundles_by_token(r, &list_from_bundle);
+		global_list->heuristic = BUNDLE_HEURISTIC_CREATIONTOKEN;
+	} else if ((result = download_bundle_list(r, &list_from_bundle,
+					   global_list, depth)))
+		goto cleanup;
+
+cleanup:
+	clear_bundle_list(&list_from_bundle);
+	return result;
+}
+
+/**
+ * This limits the recursion on fetch_bundle_uri_internal() when following
+ * bundle lists.
+ */
+static int max_bundle_uri_depth = 4;
+
+/**
+ * Recursively download all bundles advertised at the given URI
+ * to files. If the file is a bundle, then add it to the given
+ * 'list'. Otherwise, expect a bundle list and recurse on the
+ * URIs in that list according to the list mode (ANY or ALL).
+ */
+static int fetch_bundle_uri_internal(struct repository *r,
+				     struct remote_bundle_info *bundle,
+				     int depth,
+				     struct bundle_list *list)
+{
+	int result = 0;
+	struct remote_bundle_info *bcopy;
+
+	if (depth >= max_bundle_uri_depth) {
+		warning(_("exceeded bundle URI recursion limit (%d)"),
+			max_bundle_uri_depth);
+		return -1;
+	}
+
+	if (!bundle->file &&
+	    !(bundle->file = find_temp_filename())) {
+		result = -1;
+		goto cleanup;
+	}
+
+	if ((result = copy_uri_to_file(bundle->file, bundle->uri))) {
+		warning(_("failed to download bundle from URI '%s'"), bundle->uri);
+		goto cleanup;
+	}
+
+	if ((result = !is_bundle(bundle->file, 1))) {
+		result = fetch_bundle_list_in_config_format(
+				r, list, bundle, depth);
+		if (result)
+			warning(_("file at URI '%s' is not a bundle or bundle list"),
+				bundle->uri);
+		goto cleanup;
+	}
+
+	/* Copy the bundle and insert it into the global list. */
+	CALLOC_ARRAY(bcopy, 1);
+	bcopy->id = xstrdup(bundle->id);
+	bcopy->file = xstrdup(bundle->file);
+	hashmap_entry_init(&bcopy->ent, strhash(bcopy->id));
+	hashmap_add(&list->bundles, &bcopy->ent);
+
+cleanup:
+	if (result && bundle->file)
+		unlink(bundle->file);
+	return result;
+}
+
+/**
+ * This loop iterator breaks the loop with nonzero return code on the
+ * first successful unbundling of a bundle.
+ */
+static int attempt_unbundle(struct remote_bundle_info *info, void *data)
+{
+	struct repository *r = data;
+
+	if (!info->file || info->unbundled)
+		return 0;
+
+	if (!unbundle_from_file(r, info->file)) {
+		info->unbundled = 1;
+		return 1;
+	}
+
+	return 0;
+}
+
+static int unbundle_all_bundles(struct repository *r,
+				struct bundle_list *list)
+{
+	/*
+	 * Iterate through all bundles looking for ones that can
+	 * successfully unbundle. If any succeed, then perhaps another
+	 * will succeed in the next attempt.
+	 *
+	 * Keep in mind that a non-zero result for the loop here means
+	 * the loop terminated early on a successful unbundling, which
+	 * signals that we can try again.
+	 */
+	while (for_all_bundles_in_list(list, attempt_unbundle, r)) ;
+
+	return 0;
+}
+
+static int unlink_bundle(struct remote_bundle_info *info, void *data UNUSED)
+{
+	if (info->file)
+		unlink_or_warn(info->file);
+	return 0;
+}
+
+int fetch_bundle_uri(struct repository *r, const char *uri,
+		     int *has_heuristic)
+{
+	int result;
+	struct bundle_list list;
+	struct remote_bundle_info bundle = {
+		.uri = xstrdup(uri),
+		.id = xstrdup(""),
+	};
+
+	init_bundle_list(&list);
+
+	/*
+	 * Do not fetch an empty bundle URI. An empty bundle URI
+	 * could signal that a configured bundle URI has been disabled.
+	 */
+	if (!*uri) {
+		result = 0;
+		goto cleanup;
+	}
+
+	/* If a bundle is added to this global list, then it is required. */
+	list.mode = BUNDLE_MODE_ALL;
+
+	if ((result = fetch_bundle_uri_internal(r, &bundle, 0, &list)))
+		goto cleanup;
+
+	result = unbundle_all_bundles(r, &list);
+
+cleanup:
+	if (has_heuristic)
+		*has_heuristic = (list.heuristic != BUNDLE_HEURISTIC_NONE);
+	for_all_bundles_in_list(&list, unlink_bundle, NULL);
+	clear_bundle_list(&list);
+	clear_remote_bundle_info(&bundle, NULL);
+	return result;
+}
+
+int fetch_bundle_list(struct repository *r, struct bundle_list *list)
+{
+	int result;
+	struct bundle_list global_list;
+
+	/*
+	 * If the creationToken heuristic is used, then the URIs
+	 * advertised by 'list' are not nested lists and instead
+	 * direct bundles. We do not need to use global_list.
+	 */
+	if (list->heuristic == BUNDLE_HEURISTIC_CREATIONTOKEN)
+		return fetch_bundles_by_token(r, list);
+
+	init_bundle_list(&global_list);
+
+	/* If a bundle is added to this global list, then it is required. */
+	global_list.mode = BUNDLE_MODE_ALL;
+
+	if ((result = download_bundle_list(r, list, &global_list, 0)))
+		goto cleanup;
+
+	if (list->heuristic == BUNDLE_HEURISTIC_CREATIONTOKEN)
+		result = fetch_bundles_by_token(r, list);
+	else
+		result = unbundle_all_bundles(r, &global_list);
+
+cleanup:
+	for_all_bundles_in_list(&global_list, unlink_bundle, NULL);
+	clear_bundle_list(&global_list);
+	return result;
+}
+
+/**
+ * API for serve.c.
+ */
+
+int bundle_uri_advertise(struct repository *r, struct strbuf *value UNUSED)
+{
+	static int advertise_bundle_uri = -1;
+
+	if (advertise_bundle_uri != -1)
+		goto cached;
+
+	advertise_bundle_uri = 0;
+	repo_config_get_maybe_bool(r, "uploadpack.advertisebundleuris", &advertise_bundle_uri);
+
+cached:
+	return advertise_bundle_uri;
+}
+
+static int config_to_packet_line(const char *key, const char *value,
+				 const struct config_context *ctx UNUSED,
+				 void *data)
+{
+	struct packet_reader *writer = data;
+
+	if (starts_with(key, "bundle."))
+		packet_write_fmt(writer->fd, "%s=%s", key, value);
+
+	return 0;
+}
+
+int bundle_uri_command(struct repository *r,
+		       struct packet_reader *request)
+{
+	struct packet_writer writer;
+	packet_writer_init(&writer, 1);
+
+	while (packet_reader_read(request) == PACKET_READ_NORMAL)
+		die(_("bundle-uri: unexpected argument: '%s'"), request->line);
+	if (request->status != PACKET_READ_FLUSH)
+		die(_("bundle-uri: expected flush after arguments"));
+
+	/*
+	 * Read all "bundle.*" config lines to the client as key=value
+	 * packet lines.
+	 */
+	repo_config(r, config_to_packet_line, &writer);
+
+	packet_writer_flush(&writer);
+
+	return 0;
+}
+
+/**
+ * General API for {transport,connect}.c etc.
+ */
+int bundle_uri_parse_line(struct bundle_list *list, const char *line)
+{
+	int result;
+	const char *equals;
+	struct strbuf key = STRBUF_INIT;
+
+	if (!strlen(line))
+		return error(_("bundle-uri: got an empty line"));
+
+	equals = strchr(line, '=');
+
+	if (!equals)
+		return error(_("bundle-uri: line is not of the form 'key=value'"));
+	if (line == equals || !*(equals + 1))
+		return error(_("bundle-uri: line has empty key or value"));
+
+	strbuf_add(&key, line, equals - line);
+	result = bundle_list_update(key.buf, equals + 1, list);
+	strbuf_release(&key);
+
+	return result;
+}