Adding upstream version 1:2.47.2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

protocol.h

@@ -0,0 +1,55 @@
+#ifndef PROTOCOL_H
+#define PROTOCOL_H
+
+/*
+ * Intensive research over the course of many years has shown that
+ * port 9418 is totally unused by anything else. Or
+ *
+ *	Your search - "port 9418" - did not match any documents.
+ *
+ * as www.google.com puts it.
+ *
+ * This port has been properly assigned for git use by IANA:
+ * git (Assigned-9418) [I06-050728-0001].
+ *
+ *	git  9418/tcp   git pack transfer service
+ *	git  9418/udp   git pack transfer service
+ *
+ * with Linus Torvalds <torvalds@osdl.org> as the point of
+ * contact. September 2005.
+ *
+ * See https://www.iana.org/assignments/port-numbers
+ */
+#define DEFAULT_GIT_PORT 9418
+
+enum protocol_version {
+	protocol_unknown_version = -1,
+	protocol_v0 = 0,
+	protocol_v1 = 1,
+	protocol_v2 = 2,
+};
+
+/*
+ * Used by a client to determine which protocol version to request be used when
+ * communicating with a server, reflecting the configured value of the
+ * 'protocol.version' config.  If unconfigured, a value of 'protocol_v0' is
+ * returned.
+ */
+enum protocol_version get_protocol_version_config(void);
+
+/*
+ * Used by a server to determine which protocol version should be used based on
+ * a client's request, communicated via the 'GIT_PROTOCOL' environment variable
+ * by setting appropriate values for the key 'version'.  If a client doesn't
+ * request a particular protocol version, a default of 'protocol_v0' will be
+ * used.
+ */
+enum protocol_version determine_protocol_version_server(void);
+
+/*
+ * Used by a client to determine which protocol version the server is speaking
+ * based on the server's initial response.
+ */
+enum protocol_version determine_protocol_version_client(const char *server_response);
+
+#endif /* PROTOCOL_H */