Merge branch 'jt/transfer-fsck-with-promissor'

The transfer.fsckobjects configuration tells "git fetch" to
validate the data and connected-ness of objects in the received
pack; the code to perform this check has been taught about the
narrow clone's convention that missing objects that are reachable
from objects in a pack that came from a promissor remote is OK.

* jt/transfer-fsck-with-promissor:
  fetch-pack: do not check links for partial fetch
  index-pack: support checking objects but not links

Documentation/git-index-pack.txt

@@ -77,6 +77,9 @@ OPTIONS
 --check-self-contained-and-connected::
 	Die if the pack contains broken links. For internal use only.
 
+--fsck-objects::
+	Die if the pack contains broken objects. For internal use only.
+
 --threads=<n>::
 	Specifies the number of threads to spawn when resolving
 	deltas. This requires that index-pack be compiled with

builtin/index-pack.c

@@ -828,7 +828,7 @@ static void sha1_object(const void *data, struct object_entry *obj_entry,
 		free(has_data);
 	}
 
-	if (strict) {
+	if (strict || do_fsck_object) {
 		read_lock();
 		if (type == OBJ_BLOB) {
 			struct blob *blob = lookup_blob(oid);
@@ -854,7 +854,7 @@ static void sha1_object(const void *data, struct object_entry *obj_entry,
 			if (do_fsck_object &&
 			    fsck_object(obj, buf, size, &fsck_options))
 				die(_("Error in object"));
-			if (fsck_walk(obj, NULL, &fsck_options))
+			if (strict && fsck_walk(obj, NULL, &fsck_options))
 				die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 
 			if (obj->type == OBJ_TREE) {
@@ -1689,6 +1689,8 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 			} else if (!strcmp(arg, "--check-self-contained-and-connected")) {
 				strict = 1;
 				check_self_contained_and_connected = 1;
+			} else if (!strcmp(arg, "--fsck-objects")) {
+				do_fsck_object = 1;
 			} else if (!strcmp(arg, "--verify")) {
 				verify = 1;
 			} else if (!strcmp(arg, "--verify-stat")) {

fetch-pack.c

@@ -886,8 +886,17 @@ static int get_pack(struct fetch_pack_args *args,
 	    ? fetch_fsck_objects
 	    : transfer_fsck_objects >= 0
 	    ? transfer_fsck_objects
-	    : 0)
-		argv_array_push(&cmd.args, "--strict");
+	    : 0) {
+		if (args->from_promisor)
+			/*
+			 * We cannot use --strict in index-pack because it
+			 * checks both broken objects and links, but we only
+			 * want to check for broken objects.
+			 */
+			argv_array_push(&cmd.args, "--fsck-objects");
+		else
+			argv_array_push(&cmd.args, "--strict");
+	}
 
 	cmd.in = demux.out;
 	cmd.git_cmd = 1;

t/t5302-pack-index.sh

@@ -262,4 +262,9 @@ EOF
     grep "^warning:.* expected .tagger. line" err
 '
 
+test_expect_success 'index-pack --fsck-objects also warns upon missing tagger in tag' '
+    git index-pack --fsck-objects tag-test-${pack1}.pack 2>err &&
+    grep "^warning:.* expected .tagger. line" err
+'
+
 test_done

t/t5616-partial-clone.sh

@@ -143,4 +143,15 @@ test_expect_success 'manual prefetch of missing objects' '
 	test_line_count = 0 observed.oids
 '
 
+test_expect_success 'partial clone with transfer.fsckobjects=1 uses index-pack --fsck-objects' '
+	git init src &&
+	test_commit -C src x &&
+	test_config -C src uploadpack.allowfilter 1 &&
+	test_config -C src uploadpack.allowanysha1inwant 1 &&
+
+	GIT_TRACE="$(pwd)/trace" git -c transfer.fsckobjects=1 \
+		clone --filter="blob:none" "file://$(pwd)/src" dst &&
+	grep "git index-pack.*--fsck-objects" trace
+'
+
 test_done