Make pg_basebackup work with pre-9.3 servers, and add server version check.

A new 'starttli' field was added to the response of BASE_BACKUP command.
Make pg_basebackup tolerate the case that it's missing, so that it still
works with older servers.

Add an explicit check for the server version, so that you get a nicer error
message if you try to use it with a pre-9.1 server.

The streaming protocol message format changed in 9.3, so -X stream still won't
work with pre-9.3 servers. I added a version check to ReceiveXLogStream()
earlier, but write that slightly differently, so that in 9.4, it will still
work with a 9.3 server. (In 9.4, the error message needs to be adjusted to
"9.3 or above", though). Also, if the version check fails, don't retry.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/bin/pg_basebackup/pg_receivexlog.c b/src/bin/pg_basebackup/pg_receivexlog.c
index e68f8ea7079..e4da799d1fd 100644
--- a/src/bin/pg_basebackup/pg_receivexlog.c
+++ b/src/bin/pg_basebackup/pg_receivexlog.c
@@ -229,6 +229,16 @@ StreamLog(void)
 		/* Error message already written in GetConnection() */
 		return;
 
+	if (!CheckServerVersionForStreaming(conn))
+	{
+		/*
+		 * Error message already written in CheckServerVersionForStreaming().
+		 * There's no hope of recovering from a version mismatch, so don't
+		 * retry.
+		 */
+		disconnect_and_exit(1);
+	}
+
 	/*
 	 * Run IDENTIFY_SYSTEM so we can get the timeline and current xlog
 	 * position.