CEILING function returns inconsistent results based on sql_buffer_result setting

Description

Executing SELECT CEILING(t.c) on a table with a large DOUBLE value returns different results depending on the sql_buffer_result session variable. When sql_buffer_result is set to OFF, the correct value is returned. When set to ON, an incorrect value is returned.

Steps to Reproduce

1. Create Table and Insert Value:

CREATE TABLE t(c DOUBLE);

INSERT INTO t VALUES (863006000000000000);

2. Set sql_buffer_result to OFF and Query:

SET SESSION sql_buffer_result = OFF;

SELECT CEILING(t.c) FROM t;

Result: 863006000000000000

3. Set sql_buffer_result to ON and Query:

SET SESSION sql_buffer_result = ON;

SELECT CEILING(t.c) FROM t;

Result: 100000000000000000