Changed behaviour for a slave requesting master_log_pos beyond binlog file size

Slave request for a log_pos behind binlog file size may result in a
disconnection or replication error:

if binlog file is latest one slave get disconnected otherwise an error
message is returned and replication stops

server/modules/include/blr.h

@@ -185,6 +185,7 @@
 #define SLAVE_POS_READ_ERR			0xff
 #define SLAVE_POS_READ_UNSAFE			0xfe
 #define SLAVE_POS_BAD_FD			0xfd
+#define SLAVE_POS_BEYOND_EOF			0xfc
 
 /**
  * Some useful macros for examining the MySQL Response packets

server/modules/routing/binlog/blr_file.c

@@ -432,8 +432,28 @@ struct	stat	statb;
 
 	if (pos > filelen)
 	{
-		snprintf(errmsg, BINLOG_ERROR_MSG_LEN, "Requested position %lu is beyond end of the binlog file '%s', size %lu",
-			pos, file->binlogname, filelen);
+		spinlock_acquire(&router->binlog_lock);
+		spinlock_acquire(&file->lock);
+
+		if (strcmp(router->binlog_name, file->binlogname) != 0)
+		{
+			snprintf(errmsg, BINLOG_ERROR_MSG_LEN, "Requested position %lu is beyond "
+				"'closed' binlog file '%s', size %lu. Generating Error '1236'",
+				pos, file->binlogname, filelen);
+		} else {
+			snprintf(errmsg, BINLOG_ERROR_MSG_LEN, "Requested position %lu is beyond "
+				"end of the latest binlog file '%s', size %lu. Disconnecting",
+                                pos, file->binlogname, filelen);
+
+				/* Slave will be disconnected by the calling routine */
+				hdr->ok = SLAVE_POS_BEYOND_EOF;
+			}
+
+		}
+
+		spinlock_release(&file->lock);
+		spinlock_release(&router->binlog_lock);
+
 		return NULL;
 	}
 

server/modules/routing/binlog/blr_slave.c

@@ -2053,6 +2053,27 @@ char read_errmsg[BINLOG_ERROR_MSG_LEN+1];
 				read_errmsg);
 		}
 
+		if (hdr.ok == SLAVE_POS_BEYOND_EOF) {
+			MXS_ERROR("%s Slave %s:%i, server-id %d, binlog '%s', %s",
+				router->service->name,
+				slave->dcb->remote,
+				ntohs((slave->dcb->ipv4).sin_port),
+				slave->serverid,
+				slave->binlogfile,
+				read_errmsg);
+
+			/*
+			 * Close the slave session and socket
+			 * The slave will try to reconnect
+			 */
+			dcb_close(slave->dcb);
+
+#ifndef BLFILE_IN_SLAVE
+			blr_close_binlog(router, file);
+#endif
+			return 0;
+		}
+
                 if (hdr.ok == SLAVE_POS_READ_ERR) {
 			MXS_ERROR("%s Slave %s:%i, server-id %d, binlog '%s', %s",
 				router->service->name,