diff --git a/Documentation/git-http-fetch.txt b/Documentation/git-http-fetch.txt
index 4deb4893f5..9fa17b60e4 100644
--- a/Documentation/git-http-fetch.txt
+++ b/Documentation/git-http-fetch.txt
@@ -41,11 +41,17 @@ commit-id::
 		<commit-id>['\t'<filename-as-in--w>]
 
 --packfile=<hash>::
-	Instead of a commit id on the command line (which is not expected in
+	For internal use only. Instead of a commit id on the command
+	line (which is not expected in
 	this case), 'git http-fetch' fetches the packfile directly at the given
 	URL and uses index-pack to generate corresponding .idx and .keep files.
 	The hash is used to determine the name of the temporary file and is
-	arbitrary. The output of index-pack is printed to stdout.
+	arbitrary. The output of index-pack is printed to stdout. Requires
+	--index-pack-args.
+
+--index-pack-args=<args>::
+	For internal use only. The command to run on the contents of the
+	downloaded pack. Arguments are URL-encoded separated by spaces.
 
 --recover::
 	Verify that everything reachable from target is fetched.  Used after
diff --git a/Documentation/git-index-pack.txt b/Documentation/git-index-pack.txt
index 69ba904d44..7fa74b9e79 100644
--- a/Documentation/git-index-pack.txt
+++ b/Documentation/git-index-pack.txt
@@ -86,7 +86,12 @@ OPTIONS
 	Die if the pack contains broken links. For internal use only.
 
 --fsck-objects::
-	Die if the pack contains broken objects. For internal use only.
+	For internal use only.
++
+Die if the pack contains broken objects. If the pack contains a tree
+pointing to a .gitmodules blob that does not exist, prints the hash of
+that blob (for the caller to check) after the hash that goes into the
+name of the pack/idx file (see "Notes").
 
 --threads=<n>::
 	Specifies the number of threads to spawn when resolving
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 54f74c4874..bad5748807 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1712,6 +1712,22 @@ static void show_pack_info(int stat_only)
 	}
 }
 
+static int print_dangling_gitmodules(struct fsck_options *o,
+				     const struct object_id *oid,
+				     enum object_type object_type,
+				     int msg_type, const char *message)
+{
+	/*
+	 * NEEDSWORK: Plumb the MSG_ID (from fsck.c) here and use it
+	 * instead of relying on this string check.
+	 */
+	if (starts_with(message, "gitmodulesMissing")) {
+		printf("%s\n", oid_to_hex(oid));
+		return 0;
+	}
+	return fsck_error_function(o, oid, object_type, msg_type, message);
+}
+
 int cmd_index_pack(int argc, const char **argv, const char *prefix)
 {
 	int i, fix_thin_pack = 0, verify = 0, stat_only = 0, rev_index;
@@ -1932,8 +1948,13 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	else
 		close(input_fd);
 
-	if (do_fsck_object && fsck_finish(&fsck_options))
-		die(_("fsck error in pack objects"));
+	if (do_fsck_object) {
+		struct fsck_options fo = fsck_options;
+
+		fo.error_func = print_dangling_gitmodules;
+		if (fsck_finish(&fo))
+			die(_("fsck error in pack objects"));
+	}
 
 	free(objects);
 	strbuf_release(&index_name_buf);
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index b89ce31bf2..d26040c477 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -2275,7 +2275,7 @@ static const char *unpack(int err_fd, struct shallow_info *si)
 		status = start_command(&child);
 		if (status)
 			return "index-pack fork failed";
-		pack_lockfile = index_pack_lockfile(child.out);
+		pack_lockfile = index_pack_lockfile(child.out, NULL);
 		close(child.out);
 		status = finish_command(&child);
 		if (status)
diff --git a/fetch-pack.c b/fetch-pack.c
index 1eaedcb5dc..0cb59acc48 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -790,14 +790,36 @@ static void create_promisor_file(const char *keep_name,
 	strbuf_release(&promisor_name);
 }
 
+static void parse_gitmodules_oids(int fd, struct oidset *gitmodules_oids)
+{
+	int len = the_hash_algo->hexsz + 1; /* hash + NL */
+
+	do {
+		char hex_hash[GIT_MAX_HEXSZ + 1];
+		int read_len = read_in_full(fd, hex_hash, len);
+		struct object_id oid;
+		const char *end;
+
+		if (!read_len)
+			return;
+		if (read_len != len)
+			die("invalid length read %d", read_len);
+		if (parse_oid_hex(hex_hash, &oid, &end) || *end != '\n')
+			die("invalid hash");
+		oidset_insert(gitmodules_oids, &oid);
+	} while (1);
+}
+
 /*
- * Pass 1 as "only_packfile" if the pack received is the only pack in this
- * fetch request (that is, if there were no packfile URIs provided).
+ * If packfile URIs were provided, pass a non-NULL pointer to index_pack_args.
+ * The strings to pass as the --index-pack-arg arguments to http-fetch will be
+ * stored there. (It must be freed by the caller.)
  */
 static int get_pack(struct fetch_pack_args *args,
 		    int xd[2], struct string_list *pack_lockfiles,
-		    int only_packfile,
-		    struct ref **sought, int nr_sought)
+		    struct strvec *index_pack_args,
+		    struct ref **sought, int nr_sought,
+		    struct oidset *gitmodules_oids)
 {
 	struct async demux;
 	int do_keep = args->keep_pack;
@@ -805,6 +827,7 @@ static int get_pack(struct fetch_pack_args *args,
 	struct pack_header header;
 	int pass_header = 0;
 	struct child_process cmd = CHILD_PROCESS_INIT;
+	int fsck_objects = 0;
 	int ret;
 
 	memset(&demux, 0, sizeof(demux));
@@ -839,8 +862,15 @@ static int get_pack(struct fetch_pack_args *args,
 		strvec_push(&cmd.args, alternate_shallow_file);
 	}
 
-	if (do_keep || args->from_promisor) {
-		if (pack_lockfiles)
+	if (fetch_fsck_objects >= 0
+	    ? fetch_fsck_objects
+	    : transfer_fsck_objects >= 0
+	    ? transfer_fsck_objects
+	    : 0)
+		fsck_objects = 1;
+
+	if (do_keep || args->from_promisor || index_pack_args || fsck_objects) {
+		if (pack_lockfiles || fsck_objects)
 			cmd.out = -1;
 		cmd_name = "index-pack";
 		strvec_push(&cmd.args, cmd_name);
@@ -857,7 +887,7 @@ static int get_pack(struct fetch_pack_args *args,
 				     "--keep=fetch-pack %"PRIuMAX " on %s",
 				     (uintmax_t)getpid(), hostname);
 		}
-		if (only_packfile && args->check_self_contained_and_connected)
+		if (!index_pack_args && args->check_self_contained_and_connected)
 			strvec_push(&cmd.args, "--check-self-contained-and-connected");
 		else
 			/*
@@ -890,12 +920,8 @@ static int get_pack(struct fetch_pack_args *args,
 		strvec_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 			     ntohl(header.hdr_version),
 				 ntohl(header.hdr_entries));
-	if (fetch_fsck_objects >= 0
-	    ? fetch_fsck_objects
-	    : transfer_fsck_objects >= 0
-	    ? transfer_fsck_objects
-	    : 0) {
-		if (args->from_promisor || !only_packfile)
+	if (fsck_objects) {
+		if (args->from_promisor || index_pack_args)
 			/*
 			 * We cannot use --strict in index-pack because it
 			 * checks both broken objects and links, but we only
@@ -907,14 +933,26 @@ static int get_pack(struct fetch_pack_args *args,
 				     fsck_msg_types.buf);
 	}
 
+	if (index_pack_args) {
+		int i;
+
+		for (i = 0; i < cmd.args.nr; i++)
+			strvec_push(index_pack_args, cmd.args.v[i]);
+	}
+
 	cmd.in = demux.out;
 	cmd.git_cmd = 1;
 	if (start_command(&cmd))
 		die(_("fetch-pack: unable to fork off %s"), cmd_name);
-	if (do_keep && pack_lockfiles) {
-		char *pack_lockfile = index_pack_lockfile(cmd.out);
+	if (do_keep && (pack_lockfiles || fsck_objects)) {
+		int is_well_formed;
+		char *pack_lockfile = index_pack_lockfile(cmd.out, &is_well_formed);
+
+		if (!is_well_formed)
+			die(_("fetch-pack: invalid index-pack output"));
 		if (pack_lockfile)
 			string_list_append_nodup(pack_lockfiles, pack_lockfile);
+		parse_gitmodules_oids(cmd.out, gitmodules_oids);
 		close(cmd.out);
 	}
 
@@ -949,6 +987,22 @@ static int cmp_ref_by_name(const void *a_, const void *b_)
 	return strcmp(a->name, b->name);
 }
 
+static void fsck_gitmodules_oids(struct oidset *gitmodules_oids)
+{
+	struct oidset_iter iter;
+	const struct object_id *oid;
+	struct fsck_options fo = FSCK_OPTIONS_STRICT;
+
+	if (!oidset_size(gitmodules_oids))
+		return;
+
+	oidset_iter_init(gitmodules_oids, &iter);
+	while ((oid = oidset_iter_next(&iter)))
+		register_found_gitmodules(oid);
+	if (fsck_finish(&fo))
+		die("fsck failed");
+}
+
 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 				 int fd[2],
 				 const struct ref *orig_ref,
@@ -963,6 +1017,7 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 	int agent_len;
 	struct fetch_negotiator negotiator_alloc;
 	struct fetch_negotiator *negotiator;
+	struct oidset gitmodules_oids = OIDSET_INIT;
 
 	negotiator = &negotiator_alloc;
 	fetch_negotiator_init(r, negotiator);
@@ -1078,8 +1133,10 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 		alternate_shallow_file = setup_temporary_shallow(si->shallow);
 	else
 		alternate_shallow_file = NULL;
-	if (get_pack(args, fd, pack_lockfiles, 1, sought, nr_sought))
+	if (get_pack(args, fd, pack_lockfiles, NULL, sought, nr_sought,
+		     &gitmodules_oids))
 		die(_("git fetch-pack: fetch failed."));
+	fsck_gitmodules_oids(&gitmodules_oids);
 
  all_done:
 	if (negotiator)
@@ -1529,6 +1586,8 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 	int seen_ack = 0;
 	struct string_list packfile_uris = STRING_LIST_INIT_DUP;
 	int i;
+	struct strvec index_pack_args = STRVEC_INIT;
+	struct oidset gitmodules_oids = OIDSET_INIT;
 
 	negotiator = &negotiator_alloc;
 	fetch_negotiator_init(r, negotiator);
@@ -1618,7 +1677,8 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 				receive_packfile_uris(&reader, &packfile_uris);
 			process_section_header(&reader, "packfile", 0);
 			if (get_pack(args, fd, pack_lockfiles,
-				     !packfile_uris.nr, sought, nr_sought))
+				     packfile_uris.nr ? &index_pack_args : NULL,
+				     sought, nr_sought, &gitmodules_oids))
 				die(_("git fetch-pack: fetch failed."));
 			do_check_stateless_delimiter(args, &reader);
 
@@ -1630,6 +1690,7 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 	}
 
 	for (i = 0; i < packfile_uris.nr; i++) {
+		int j;
 		struct child_process cmd = CHILD_PROCESS_INIT;
 		char packname[GIT_MAX_HEXSZ + 1];
 		const char *uri = packfile_uris.items[i].string +
@@ -1639,6 +1700,9 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 		strvec_pushf(&cmd.args, "--packfile=%.*s",
 			     (int) the_hash_algo->hexsz,
 			     packfile_uris.items[i].string);
+		for (j = 0; j < index_pack_args.nr; j++)
+			strvec_pushf(&cmd.args, "--index-pack-arg=%s",
+				     index_pack_args.v[j]);
 		strvec_push(&cmd.args, uri);
 		cmd.git_cmd = 1;
 		cmd.no_stdin = 1;
@@ -1657,6 +1721,8 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 
 		packname[the_hash_algo->hexsz] = '\0';
 
+		parse_gitmodules_oids(cmd.out, &gitmodules_oids);
+
 		close(cmd.out);
 
 		if (finish_command(&cmd))
@@ -1674,6 +1740,9 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 						 packname));
 	}
 	string_list_clear(&packfile_uris, 0);
+	strvec_clear(&index_pack_args);
+
+	fsck_gitmodules_oids(&gitmodules_oids);
 
 	if (negotiator)
 		negotiator->release(negotiator);
diff --git a/fsck.c b/fsck.c
index 71134fdefa..e3030f3b35 100644
--- a/fsck.c
+++ b/fsck.c
@@ -1276,6 +1276,11 @@ int fsck_error_function(struct fsck_options *o,
 	return 1;
 }
 
+void register_found_gitmodules(const struct object_id *oid)
+{
+	oidset_insert(&gitmodules_found, oid);
+}
+
 int fsck_finish(struct fsck_options *options)
 {
 	int ret = 0;
diff --git a/fsck.h b/fsck.h
index 423c467feb..733378f126 100644
--- a/fsck.h
+++ b/fsck.h
@@ -62,6 +62,8 @@ int fsck_walk(struct object *obj, void *data, struct fsck_options *options);
 int fsck_object(struct object *obj, void *data, unsigned long size,
 	struct fsck_options *options);
 
+void register_found_gitmodules(const struct object_id *oid);
+
 /*
  * fsck a tag, and pass info about it back to the caller. This is
  * exposed fsck_object() internals for git-mktag(1).
diff --git a/http-fetch.c b/http-fetch.c
index c4ccc5fea9..fa642462a9 100644
--- a/http-fetch.c
+++ b/http-fetch.c
@@ -3,6 +3,7 @@
 #include "exec-cmd.h"
 #include "http.h"
 #include "walker.h"
+#include "strvec.h"
 
 static const char http_fetch_usage[] = "git http-fetch "
 "[-c] [-t] [-a] [-v] [--recover] [-w ref] [--stdin | --packfile=hash | commit-id] url";
@@ -44,7 +45,8 @@ static int fetch_using_walker(const char *raw_url, int get_verbosely,
 }
 
 static void fetch_single_packfile(struct object_id *packfile_hash,
-				  const char *url) {
+				  const char *url,
+				  const char **index_pack_args) {
 	struct http_pack_request *preq;
 	struct slot_results results;
 	int ret;
@@ -55,7 +57,8 @@ static void fetch_single_packfile(struct object_id *packfile_hash,
 	if (preq == NULL)
 		die("couldn't create http pack request");
 	preq->slot->results = &results;
-	preq->generate_keep = 1;
+	preq->index_pack_args = index_pack_args;
+	preq->preserve_index_pack_stdout = 1;
 
 	if (start_active_slot(preq->slot)) {
 		run_active_slot(preq->slot);
@@ -86,6 +89,7 @@ int cmd_main(int argc, const char **argv)
 	int packfile = 0;
 	int nongit;
 	struct object_id packfile_hash;
+	struct strvec index_pack_args = STRVEC_INIT;
 
 	setup_git_directory_gently(&nongit);
 
@@ -112,6 +116,8 @@ int cmd_main(int argc, const char **argv)
 			packfile = 1;
 			if (parse_oid_hex(p, &packfile_hash, &end) || *end)
 				die(_("argument to --packfile must be a valid hash (got '%s')"), p);
+		} else if (skip_prefix(argv[arg], "--index-pack-arg=", &p)) {
+			strvec_push(&index_pack_args, p);
 		}
 		arg++;
 	}
@@ -124,10 +130,18 @@ int cmd_main(int argc, const char **argv)
 	git_config(git_default_config, NULL);
 
 	if (packfile) {
-		fetch_single_packfile(&packfile_hash, argv[arg]);
+		if (!index_pack_args.nr)
+			die(_("--packfile requires --index-pack-args"));
+
+		fetch_single_packfile(&packfile_hash, argv[arg],
+				      index_pack_args.v);
+
 		return 0;
 	}
 
+	if (index_pack_args.nr)
+		die(_("--index-pack-args can only be used with --packfile"));
+
 	if (commits_on_stdin) {
 		commits = walker_targets_stdin(&commit_id, &write_ref);
 	} else {
diff --git a/http.c b/http.c
index 8b23a546af..f8ea28bb2e 100644
--- a/http.c
+++ b/http.c
@@ -2259,6 +2259,9 @@ void release_http_pack_request(struct http_pack_request *preq)
 	free(preq);
 }
 
+static const char *default_index_pack_args[] =
+	{"index-pack", "--stdin", NULL};
+
 int finish_http_pack_request(struct http_pack_request *preq)
 {
 	struct child_process ip = CHILD_PROCESS_INIT;
@@ -2270,17 +2273,15 @@ int finish_http_pack_request(struct http_pack_request *preq)
 
 	tmpfile_fd = xopen(preq->tmpfile.buf, O_RDONLY);
 
-	strvec_push(&ip.args, "index-pack");
-	strvec_push(&ip.args, "--stdin");
 	ip.git_cmd = 1;
 	ip.in = tmpfile_fd;
-	if (preq->generate_keep) {
-		strvec_pushf(&ip.args, "--keep=git %"PRIuMAX,
-			     (uintmax_t)getpid());
+	ip.argv = preq->index_pack_args ? preq->index_pack_args
+					: default_index_pack_args;
+
+	if (preq->preserve_index_pack_stdout)
 		ip.out = 0;
-	} else {
+	else
 		ip.no_stdout = 1;
-	}
 
 	if (run_command(&ip)) {
 		ret = -1;
diff --git a/http.h b/http.h
index 5de792ef3f..bf3d1270ad 100644
--- a/http.h
+++ b/http.h
@@ -218,12 +218,12 @@ struct http_pack_request {
 	char *url;
 
 	/*
-	 * If this is true, finish_http_pack_request() will pass "--keep" to
-	 * index-pack, resulting in the creation of a keep file, and will not
-	 * suppress its stdout (that is, the "keep\t<hash>\n" line will be
-	 * printed to stdout).
+	 * index-pack command to run. Must be terminated by NULL.
+	 *
+	 * If NULL, defaults to	{"index-pack", "--stdin", NULL}.
 	 */
-	unsigned generate_keep : 1;
+	const char **index_pack_args;
+	unsigned preserve_index_pack_stdout : 1;
 
 	FILE *packfile;
 	struct strbuf tmpfile;
diff --git a/pack-write.c b/pack-write.c
index 680c36755d..2ca85a9d16 100644
--- a/pack-write.c
+++ b/pack-write.c
@@ -380,7 +380,7 @@ void fixup_pack_header_footer(int pack_fd,
 	fsync_or_die(pack_fd, pack_name);
 }
 
-char *index_pack_lockfile(int ip_out)
+char *index_pack_lockfile(int ip_out, int *is_well_formed)
 {
 	char packname[GIT_MAX_HEXSZ + 6];
 	const int len = the_hash_algo->hexsz + 6;
@@ -394,11 +394,17 @@ char *index_pack_lockfile(int ip_out)
 	 */
 	if (read_in_full(ip_out, packname, len) == len && packname[len-1] == '\n') {
 		const char *name;
+
+		if (is_well_formed)
+			*is_well_formed = 1;
 		packname[len-1] = 0;
 		if (skip_prefix(packname, "keep\t", &name))
 			return xstrfmt("%s/pack/pack-%s.keep",
 				       get_object_directory(), name);
+		return NULL;
 	}
+	if (is_well_formed)
+		*is_well_formed = 0;
 	return NULL;
 }
 
diff --git a/pack.h b/pack.h
index afdcf8f5c7..857cbd5bd4 100644
--- a/pack.h
+++ b/pack.h
@@ -87,7 +87,7 @@ int verify_pack_index(struct packed_git *);
 int verify_pack(struct repository *, struct packed_git *, verify_fn fn, struct progress *, uint32_t);
 off_t write_pack_header(struct hashfile *f, uint32_t);
 void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
-char *index_pack_lockfile(int fd);
+char *index_pack_lockfile(int fd, int *is_well_formed);
 
 struct ref;
 
diff --git a/t/t5550-http-fetch-dumb.sh b/t/t5550-http-fetch-dumb.sh
index 2ecb06bb63..6d9142afc3 100755
--- a/t/t5550-http-fetch-dumb.sh
+++ b/t/t5550-http-fetch-dumb.sh
@@ -227,7 +227,10 @@ test_expect_success 'http-fetch --packfile' '
 
 	git init packfileclient &&
 	p=$(cd "$HTTPD_DOCUMENT_ROOT_PATH"/repo_pack.git && ls objects/pack/pack-*.pack) &&
-	git -C packfileclient http-fetch --packfile=$ARBITRARY "$HTTPD_URL"/dumb/repo_pack.git/$p >out &&
+	git -C packfileclient http-fetch --packfile=$ARBITRARY \
+		--index-pack-arg=index-pack --index-pack-arg=--stdin \
+		--index-pack-arg=--keep \
+		"$HTTPD_URL"/dumb/repo_pack.git/$p >out &&
 
 	grep "^keep.[0-9a-f]\{16,\}$" out &&
 	cut -c6- out >packhash &&
diff --git a/t/t5702-protocol-v2.sh b/t/t5702-protocol-v2.sh
index 9113d209c5..994a76ca3c 100755
--- a/t/t5702-protocol-v2.sh
+++ b/t/t5702-protocol-v2.sh
@@ -875,11 +875,10 @@ test_expect_success 'part of packfile response provided as URI' '
 	test -f hfound &&
 	test -f h2found &&
 
-	# Ensure that there are exactly 6 files (3 .pack and 3 .idx).
-	ls http_child/.git/objects/pack/*.pack >packlist &&
-	ls http_child/.git/objects/pack/*.idx >idxlist &&
-	test_line_count = 3 idxlist &&
-	test_line_count = 3 packlist
+	# Ensure that there are exactly 3 packfiles with associated .idx
+	ls http_child/.git/objects/pack/*.pack \
+	    http_child/.git/objects/pack/*.idx >filelist &&
+	test_line_count = 6 filelist
 '
 
 test_expect_success 'fetching with valid packfile URI but invalid hash fails' '
@@ -931,11 +930,10 @@ test_expect_success 'packfile-uri with transfer.fsckobjects' '
 		-c fetch.uriprotocols=http,https \
 		clone "$HTTPD_URL/smart/http_parent" http_child &&
 
-	# Ensure that there are exactly 4 files (2 .pack and 2 .idx).
-	ls http_child/.git/objects/pack/*.pack >packlist &&
-	ls http_child/.git/objects/pack/*.idx >idxlist &&
-	test_line_count = 2 idxlist &&
-	test_line_count = 2 packlist
+	# Ensure that there are exactly 2 packfiles with associated .idx
+	ls http_child/.git/objects/pack/*.pack \
+	    http_child/.git/objects/pack/*.idx >filelist &&
+	test_line_count = 4 filelist
 '
 
 test_expect_success 'packfile-uri with transfer.fsckobjects fails on bad object' '
@@ -968,6 +966,54 @@ test_expect_success 'packfile-uri with transfer.fsckobjects fails on bad object'
 	test_i18ngrep "invalid author/committer line - missing email" error
 '
 
+test_expect_success 'packfile-uri with transfer.fsckobjects succeeds when .gitmodules is separate from tree' '
+	P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
+	rm -rf "$P" http_child &&
+
+	git init "$P" &&
+	git -C "$P" config "uploadpack.allowsidebandall" "true" &&
+
+	echo "[submodule libfoo]" >"$P/.gitmodules" &&
+	echo "path = include/foo" >>"$P/.gitmodules" &&
+	echo "url = git://example.com/git/lib.git" >>"$P/.gitmodules" &&
+	git -C "$P" add .gitmodules &&
+	git -C "$P" commit -m x &&
+
+	configure_exclusion "$P" .gitmodules >h &&
+
+	sane_unset GIT_TEST_SIDEBAND_ALL &&
+	git -c protocol.version=2 -c transfer.fsckobjects=1 \
+		-c fetch.uriprotocols=http,https \
+		clone "$HTTPD_URL/smart/http_parent" http_child &&
+
+	# Ensure that there are exactly 2 packfiles with associated .idx
+	ls http_child/.git/objects/pack/*.pack \
+	    http_child/.git/objects/pack/*.idx >filelist &&
+	test_line_count = 4 filelist
+'
+
+test_expect_success 'packfile-uri with transfer.fsckobjects fails when .gitmodules separate from tree is invalid' '
+	P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
+	rm -rf "$P" http_child err &&
+
+	git init "$P" &&
+	git -C "$P" config "uploadpack.allowsidebandall" "true" &&
+
+	echo "[submodule \"..\"]" >"$P/.gitmodules" &&
+	echo "path = include/foo" >>"$P/.gitmodules" &&
+	echo "url = git://example.com/git/lib.git" >>"$P/.gitmodules" &&
+	git -C "$P" add .gitmodules &&
+	git -C "$P" commit -m x &&
+
+	configure_exclusion "$P" .gitmodules >h &&
+
+	sane_unset GIT_TEST_SIDEBAND_ALL &&
+	test_must_fail git -c protocol.version=2 -c transfer.fsckobjects=1 \
+		-c fetch.uriprotocols=http,https \
+		clone "$HTTPD_URL/smart/http_parent" http_child 2>err &&
+	test_i18ngrep "disallowed submodule name" err
+'
+
 # DO NOT add non-httpd-specific tests here, because the last part of this
 # test script is only executed when httpd is available and enabled.