Merge branch 'jc/transport-do-not-use-connect-twice-in-fetch'

The auto-tag-following code in "git fetch" tries to reuse the same
transport twice when the serving end does not cooperate and does
not give tags that point to commits that are asked for as part of
the primary transfer.  Unfortunately, Git-aware transport helper
interface is not designed to be used more than once, hence this
does not work over smart-http transfer.

* jc/transport-do-not-use-connect-twice-in-fetch:
  builtin/fetch.c: Fix a sparse warning
  fetch: work around "transport-take-over" hack
  fetch: refactor code that fetches leftover tags
  fetch: refactor code that prepares a transport
  fetch: rename file-scope global "transport" to "gtransport"
  t5802: add test for connect helper

1 files changed, 56 insertions, 33 deletions

diff --git a/builtin/fetch.c b/builtin/fetch.c
index 5936539552..9e654efa3b 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -40,7 +40,8 @@ static int tags = TAGS_DEFAULT, unshallow;
 static const char *depth;
 static const char *upload_pack;
 static struct strbuf default_rla = STRBUF_INIT;
-static struct transport *transport;
+static struct transport *gtransport;
+static struct transport *gsecondary;
 static const char *submodule_prefix = "";
 static const char *recurse_submodules_default;
 
@@ -108,8 +109,10 @@ static struct option builtin_fetch_options[] = {
 
 static void unlock_pack(void)
 {
-	if (transport)
-		transport_unlock_pack(transport);
+	if (gtransport)
+		transport_unlock_pack(gtransport);
+	if (gsecondary)
+		transport_unlock_pack(gsecondary);
 }
 
 static void unlock_pack_on_signal(int signo)
@@ -733,6 +736,48 @@ static int truncate_fetch_head(void)
 	return 0;
 }
 
+static void set_option(struct transport *transport, const char *name, const char *value)
+{
+	int r = transport_set_option(transport, name, value);
+	if (r < 0)
+		die(_("Option \"%s\" value \"%s\" is not valid for %s"),
+		    name, value, transport->url);
+	if (r > 0)
+		warning(_("Option \"%s\" is ignored for %s\n"),
+			name, transport->url);
+}
+
+static struct transport *prepare_transport(struct remote *remote)
+{
+	struct transport *transport;
+	transport = transport_get(remote, NULL);
+	transport_set_verbosity(transport, verbosity, progress);
+	if (upload_pack)
+		set_option(transport, TRANS_OPT_UPLOADPACK, upload_pack);
+	if (keep)
+		set_option(transport, TRANS_OPT_KEEP, "yes");
+	if (depth)
+		set_option(transport, TRANS_OPT_DEPTH, depth);
+	return transport;
+}
+
+static void backfill_tags(struct transport *transport, struct ref *ref_map)
+{
+	if (transport->cannot_reuse) {
+		gsecondary = prepare_transport(transport->remote);
+		transport = gsecondary;
+	}
+
+	transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
+	transport_set_option(transport, TRANS_OPT_DEPTH, "0");
+	fetch_refs(transport, ref_map);
+
+	if (gsecondary) {
+		transport_disconnect(gsecondary);
+		gsecondary = NULL;
+	}
+}
+
 static int do_fetch(struct transport *transport,
 		    struct refspec *refs, int ref_count)
 {
@@ -819,11 +864,8 @@ static int do_fetch(struct transport *transport,
 		struct ref **tail = &ref_map;
 		ref_map = NULL;
 		find_non_local_tags(transport, &ref_map, &tail);
-		if (ref_map) {
-			transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
-			transport_set_option(transport, TRANS_OPT_DEPTH, "0");
-			fetch_refs(transport, ref_map);
-		}
+		if (ref_map)
+			backfill_tags(transport, ref_map);
 		free_refs(ref_map);
 	}
 
@@ -832,17 +874,6 @@ static int do_fetch(struct transport *transport,
 	return retcode;
 }
 
-static void set_option(const char *name, const char *value)
-{
-	int r = transport_set_option(transport, name, value);
-	if (r < 0)
-		die(_("Option \"%s\" value \"%s\" is not valid for %s"),
-			name, value, transport->url);
-	if (r > 0)
-		warning(_("Option \"%s\" is ignored for %s\n"),
-			name, transport->url);
-}
-
 static int get_one_remote_for_fetch(struct remote *remote, void *priv)
 {
 	struct string_list *list = priv;
@@ -965,26 +996,18 @@ static int fetch_one(struct remote *remote, int argc, const char **argv)
 		die(_("No remote repository specified.  Please, specify either a URL or a\n"
 		    "remote name from which new revisions should be fetched."));
 
-	transport = transport_get(remote, NULL);
+	gtransport = prepare_transport(remote);
 
 	if (prune < 0) {
 		/* no command line request */
-		if (0 <= transport->remote->prune)
-			prune = transport->remote->prune;
+		if (0 <= gtransport->remote->prune)
+			prune = gtransport->remote->prune;
 		else if (0 <= fetch_prune_config)
 			prune = fetch_prune_config;
 		else
 			prune = PRUNE_BY_DEFAULT;
 	}
 
-	transport_set_verbosity(transport, verbosity, progress);
-	if (upload_pack)
-		set_option(TRANS_OPT_UPLOADPACK, upload_pack);
-	if (keep)
-		set_option(TRANS_OPT_KEEP, "yes");
-	if (depth)
-		set_option(TRANS_OPT_DEPTH, depth);
-
 	if (argc > 0) {
 		int j = 0;
 		refs = xcalloc(argc + 1, sizeof(const char *));
@@ -1010,10 +1033,10 @@ static int fetch_one(struct remote *remote, int argc, const char **argv)
 	sigchain_push_common(unlock_pack_on_signal);
 	atexit(unlock_pack);
 	refspec = parse_fetch_refspec(ref_nr, refs);
-	exit_code = do_fetch(transport, refspec, ref_nr);
+	exit_code = do_fetch(gtransport, refspec, ref_nr);
 	free_refspec(ref_nr, refspec);
-	transport_disconnect(transport);
-	transport = NULL;
+	transport_disconnect(gtransport);
+	gtransport = NULL;
 	return exit_code;
 }