Complain with proper error message if streaming stops prematurely

In particular, with a controlled shutdown of the master, pg_basebackup
with streaming log could terminate without an error message, even though
the backup is not consistent.

In passing, fix a few cases where walfile wasn't properly set to -1 after
closing.

Fujii Masao

src/bin/pg_basebackup/receivelog.c

@@ -611,11 +611,20 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline,
 	}
 	PQclear(res);
 
+	/* Complain if we've not reached stop point yet */
+	if (stream_stop != NULL && !stream_stop(blockpos, timeline, false))
+	{
+		fprintf(stderr, _("%s: replication stream was terminated before stop point\n"),
+				progname);
+		goto error;
+	}
+
 	if (copybuf != NULL)
 		PQfreemem(copybuf);
 	if (walfile != -1 && close(walfile) != 0)
 		fprintf(stderr, _("%s: could not close file %s: %s\n"),
 				progname, current_walfile_name, strerror(errno));
+	walfile = -1;
 	return true;
 
 error:
@@ -624,5 +633,6 @@ error:
 	if (walfile != -1 && close(walfile) != 0)
 		fprintf(stderr, _("%s: could not close file %s: %s\n"),
 				progname, current_walfile_name, strerror(errno));
+	walfile = -1;
 	return false;
 }