[PATCH RFC 3/5] fetch-object-info: return a status instead of dying

[Pablo Sabater <pabloosabaterr@gmail.com>]

A subsequent commit needs fetch_object_info() not to die() when the
object-info capability is not enabled on the server, so that it can
fall back.

Make fetch_object_info() return FETCH_OBJECT_INFO_NOT_ENABLED instead
of die()'ing when the server does not advertise the object-info
capability, and propagate the status through the transport layer so
that callers of transport_fetch_object_info() can act on it. It is now
up to them whether to die() or fall back.

cat-file now dies by itself on FETCH_OBJECT_INFO_NOT_ENABLED, so its
behavior is unchanged.

Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
---
 builtin/cat-file.c   |  4 ++++
 fetch-object-info.c  | 17 +++++++++--------
 fetch-object-info.h  | 18 +++++++++++-------
 transport-helper.c   |  6 +++---
 transport-internal.h |  8 ++++----
 transport.c          | 29 +++++++++++++++--------------
 transport.h          |  7 ++++---
 7 files changed, 50 insertions(+), 39 deletions(-)

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 8870a210ec..f4758f2203 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -726,6 +726,10 @@ static int get_remote_info(int argc,
 
 	retval = transport_fetch_object_info(gtransport, object_info_oids,
 					     results);
+
+	if (retval == FETCH_OBJECT_INFO_NOT_ENABLED)
+		die(_("object-info capability is not enabled on the server"));
+
 cleanup:
 	transport_disconnect(gtransport);
 	return retval;
diff --git a/fetch-object-info.c b/fetch-object-info.c
index 0a58308f9b..7e4c922d27 100644
--- a/fetch-object-info.c
+++ b/fetch-object-info.c
@@ -52,13 +52,13 @@ static int parse_object_size(const char *s, size_t *res)
 	return 0;
 }
 
-void fetch_object_info(const enum protocol_version version,
-		       const struct string_list *server_options,
-		       const struct oid_array *oids,
-		       struct packet_reader *reader,
-		       struct fetch_object_info_results *results,
-		       const int stateless_rpc,
-		       const int fd_out)
+enum fetch_object_info_status fetch_object_info(const enum protocol_version version,
+						const struct string_list *server_options,
+						const struct oid_array *oids,
+						struct packet_reader *reader,
+						struct fetch_object_info_results *results,
+						const int stateless_rpc,
+						const int fd_out)
 {
 	unsigned ask_size = 0;
 	unsigned ask_type = 0;
@@ -72,7 +72,7 @@ void fetch_object_info(const enum protocol_version version,
 	switch (version) {
 	case protocol_v2:
 		if (!server_supports_v2("object-info"))
-			die(_("object-info capability is not enabled on the server"));
+			return FETCH_OBJECT_INFO_NOT_ENABLED;
 
 		if (results->wants_size &&
 		    server_supports_feature("object-info", "size", 0))
@@ -188,6 +188,7 @@ void fetch_object_info(const enum protocol_version version,
 		    (uintmax_t)oids->nr);
 
 	check_stateless_delimiter(stateless_rpc, reader, "stateless delimiter expected");
+	return FETCH_OBJECT_INFO_OK;
 }
 
 void free_fetch_object_info_results(struct fetch_object_info_results *results)
diff --git a/fetch-object-info.h b/fetch-object-info.h
index 663a7f3ae7..9d2750bc93 100644
--- a/fetch-object-info.h
+++ b/fetch-object-info.h
@@ -32,14 +32,18 @@ struct oid_array;
  * the server both advertised and answered with. An array left NULL means the
  * attribute is not available.
  * Release them with free_fetch_object_info_results().
+ *
+ * Returns FETCH_OBJECT_INFO_NOT_ENABLED if the server does not advertise the
+ * object-info capability, FETCH_OBJECT_INFO_OK otherwise.
+ * die()'s on any other error.
  */
-void fetch_object_info(enum protocol_version version,
-		       const struct string_list *server_options,
-		       const struct oid_array *oids,
-		       struct packet_reader *reader,
-		       struct fetch_object_info_results *results,
-		       int stateless_rpc,
-		       int fd_out);
+enum fetch_object_info_status fetch_object_info(enum protocol_version version,
+						const struct string_list *server_options,
+						const struct oid_array *oids,
+						struct packet_reader *reader,
+						struct fetch_object_info_results *results,
+						int stateless_rpc,
+						int fd_out);
 
 void free_fetch_object_info_results(struct fetch_object_info_results *results);
 
diff --git a/transport-helper.c b/transport-helper.c
index d5a064d386..855b53da59 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -786,9 +786,9 @@ static int fetch_refs(struct transport *transport,
 	return -1;
 }
 
-static int fetch_object_info_helper(struct transport *transport,
-				    const struct oid_array *oids,
-				    struct fetch_object_info_results *results)
+static enum fetch_object_info_status fetch_object_info_helper(struct transport *transport,
+							      const struct oid_array *oids,
+							      struct fetch_object_info_results *results)
 {
 	get_helper(transport);
 	if (process_connect(transport, 0))
diff --git a/transport-internal.h b/transport-internal.h
index 626ceaae2b..067134081c 100644
--- a/transport-internal.h
+++ b/transport-internal.h
@@ -2,13 +2,13 @@
 #define TRANSPORT_INTERNAL_H
 
 #include "connect.h"
+#include "fetch-object-info.h"
 
 struct ref;
 struct transport;
 struct strvec;
 struct transport_ls_refs_options;
 struct oid_array;
-struct fetch_object_info_results;
 
 struct transport_vtable {
 	/**
@@ -53,9 +53,9 @@ struct transport_vtable {
 	 *
 	 * Uses object-info capability of v2 protocol.
 	 */
-	int (*fetch_object_info)(struct transport *transport,
-				 const struct oid_array *oids,
-				 struct fetch_object_info_results *results);
+	enum fetch_object_info_status (*fetch_object_info)(struct transport *transport,
+							   const struct oid_array *oids,
+							   struct fetch_object_info_results *results);
 
 	/**
 	 * Push the objects and refs. Send the necessary objects, and
diff --git a/transport.c b/transport.c
index 25e2c14a7b..561764cb6a 100644
--- a/transport.c
+++ b/transport.c
@@ -433,11 +433,11 @@ static int get_bundle_uri(struct transport *transport)
 				     transport->bundles, stateless_rpc);
 }
 
-static int fetch_object_info_via_pack(struct transport *transport,
-				      const struct oid_array *oids,
-				      struct fetch_object_info_results *results)
+static enum fetch_object_info_status fetch_object_info_via_pack(struct transport *transport,
+								const struct oid_array *oids,
+								struct fetch_object_info_results *results)
 {
-	int ret = 0;
+	enum fetch_object_info_status ret = FETCH_OBJECT_INFO_OK;
 	struct git_transport_data *data = transport->data;
 	struct packet_reader reader;
 
@@ -450,26 +450,27 @@ static int fetch_object_info_via_pack(struct transport *transport,
 	data->version = discover_version(&reader);
 	transport->hash_algo = reader.hash_algo;
 
-	fetch_object_info(data->version,
-			  transport->server_options,
-			  oids,
-			  &reader,
-			  results,
-			  transport->stateless_rpc, data->fd[1]);
+	ret = fetch_object_info(data->version,
+				transport->server_options,
+				oids,
+				&reader,
+				results,
+				transport->stateless_rpc,
+				data->fd[1]);
 
 	close(data->fd[0]);
 	if (data->fd[1] >= 0)
 		close(data->fd[1]);
 	if (finish_connect(data->conn))
-		ret = -1;
+		ret = FETCH_OBJECT_INFO_ERR;
 	data->conn = NULL;
 
 	return ret;
 }
 
-int transport_fetch_object_info(struct transport *transport,
-				const struct oid_array *oids,
-				struct fetch_object_info_results *results)
+enum fetch_object_info_status transport_fetch_object_info(struct transport *transport,
+							  const struct oid_array *oids,
+							  struct fetch_object_info_results *results)
 {
 	if (!transport->vtable->fetch_object_info)
 		die(_("remote does not support object-info"));
diff --git a/transport.h b/transport.h
index 39193d0077..c1671639d6 100644
--- a/transport.h
+++ b/transport.h
@@ -1,6 +1,7 @@
 #ifndef TRANSPORT_H
 #define TRANSPORT_H
 
+#include "fetch-object-info.h"
 #include "run-command.h"
 #include "remote.h"
 #include "list-objects-filter-options.h"
@@ -314,9 +315,9 @@ int transport_fetch_refs(struct transport *transport, struct ref *refs);
 /*
  * Fetch the object info from remote
  */
-int transport_fetch_object_info(struct transport *transport,
-				const struct oid_array *oids,
-				struct fetch_object_info_results *results);
+enum fetch_object_info_status transport_fetch_object_info(struct transport *transport,
+							  const struct oid_array *oids,
+							  struct fetch_object_info_results *results);
 
 /*
  * If this flag is set, unlocking will avoid to call non-async-signal-safe

-- 
2.54.0