Merge branch 'rc/fetch-refetch'

"git fetch --refetch" learned to fetch everything without telling
the other side what we already have, which is useful when you
cannot trust what you have in the local object store.

* rc/fetch-refetch:
  docs: mention --refetch fetch option
  fetch: after refetch, encourage auto gc repacking
  t5615-partial-clone: add test for fetch --refetch
  fetch: add --refetch option
  builtin/fetch-pack: add --refetch option
  fetch-pack: add refetch
  fetch-negotiator: add specific noop initializer

2 files changed, 36 insertions, 2 deletions

diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index c4b9104f9b..f045bbbe94 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -153,6 +153,10 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 			args.from_promisor = 1;
 			continue;
 		}
+		if (!strcmp("--refetch", arg)) {
+			args.refetch = 1;
+			continue;
+		}
 		if (skip_prefix(arg, ("--filter="), &arg)) {
 			parse_list_objects_filter(&args.filter_options, arg);
 			continue;
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 9b4018f62c..e3791f09ed 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -59,7 +59,7 @@ static int prune_tags = -1; /* unspecified */
 
 static int all, append, dry_run, force, keep, multiple, update_head_ok;
 static int write_fetch_head = 1;
-static int verbosity, deepen_relative, set_upstream;
+static int verbosity, deepen_relative, set_upstream, refetch;
 static int progress = -1;
 static int enable_auto_gc = 1;
 static int tags = TAGS_DEFAULT, unshallow, update_shallow, deepen;
@@ -190,6 +190,9 @@ static struct option builtin_fetch_options[] = {
 	OPT_SET_INT_F(0, "unshallow", &unshallow,
 		      N_("convert to a complete repository"),
 		      1, PARSE_OPT_NONEG),
+	OPT_SET_INT_F(0, "refetch", &refetch,
+		      N_("re-fetch without negotiating common commits"),
+		      1, PARSE_OPT_NONEG),
 	{ OPTION_STRING, 0, "submodule-prefix", &submodule_prefix, N_("dir"),
 		   N_("prepend this to submodule path output"), PARSE_OPT_HIDDEN },
 	OPT_CALLBACK_F(0, "recurse-submodules-default",
@@ -1305,6 +1308,14 @@ static int check_exist_and_connected(struct ref *ref_map)
 		return -1;
 
 	/*
+	 * Similarly, if we need to refetch, we always want to perform a full
+	 * fetch ignoring existing objects.
+	 */
+	if (refetch)
+		return -1;
+
+
+	/*
 	 * check_connected() allows objects to merely be promised, but
 	 * we need all direct targets to exist.
 	 */
@@ -1517,6 +1528,8 @@ static struct transport *prepare_transport(struct remote *remote, int deepen)
 		set_option(transport, TRANS_OPT_DEEPEN_RELATIVE, "yes");
 	if (update_shallow)
 		set_option(transport, TRANS_OPT_UPDATE_SHALLOW, "yes");
+	if (refetch)
+		set_option(transport, TRANS_OPT_REFETCH, "yes");
 	if (filter_options.choice) {
 		const char *spec =
 			expand_list_objects_filter_spec(&filter_options);
@@ -2293,8 +2306,25 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 					     NULL);
 	}
 
-	if (enable_auto_gc)
+	if (enable_auto_gc) {
+		if (refetch) {
+			/*
+			 * Hint auto-maintenance strongly to encourage repacking,
+			 * but respect config settings disabling it.
+			 */
+			int opt_val;
+			if (git_config_get_int("gc.autopacklimit", &opt_val))
+				opt_val = -1;
+			if (opt_val != 0)
+				git_config_push_parameter("gc.autoPackLimit=1");
+
+			if (git_config_get_int("maintenance.incremental-repack.auto", &opt_val))
+				opt_val = -1;
+			if (opt_val != 0)
+				git_config_push_parameter("maintenance.incremental-repack.auto=-1");
+		}
 		run_auto_maintenance(verbosity < 0);
+	}
 
  cleanup:
 	string_list_clear(&list, 0);