Bug#31177: Server variables can't be set to their current values

Default values of variables were not subject to upper/lower bounds
and step, while setting variables was. Bounds and step are also
applied to defaults now; defaults are corrected quietly, values
given by the user are corrected, and a correction-warning is thrown
as needed. Lastly, very large values could wrap around, starting
from 0 again. They are bounded at the maximum value for the
respective data-type now if no lower maximum is specified in the
variable's definition.

1 files changed, 28 insertions, 2 deletions

diff --git a/mysql-test/r/variables.result b/mysql-test/r/variables.result
index 47cd96b90b7..9c360ef4ab3 100644
--- a/mysql-test/r/variables.result
+++ b/mysql-test/r/variables.result
@@ -214,6 +214,8 @@ net_read_timeout	600
 net_retry_count	10
 net_write_timeout	500
 set net_buffer_length=1;
+Warnings:
+Warning	1292	Truncated incorrect net_buffer_length value: '1'
 show variables like 'net_buffer_length';
 Variable_name	Value
 net_buffer_length	1024
@@ -238,7 +240,7 @@ show variables like '%alloc%';
 Variable_name	Value
 query_alloc_block_size	8192
 query_prealloc_size	8192
-range_alloc_block_size	2048
+range_alloc_block_size	4096
 transaction_alloc_block_size	8192
 transaction_prealloc_size	4096
 set @@range_alloc_block_size=1024*16;
@@ -263,7 +265,7 @@ show variables like '%alloc%';
 Variable_name	Value
 query_alloc_block_size	8192
 query_prealloc_size	8192
-range_alloc_block_size	2048
+range_alloc_block_size	4096
 transaction_alloc_block_size	8192
 transaction_prealloc_size	4096
 SELECT @@version LIKE 'non-existent';
@@ -321,6 +323,8 @@ select @@autocommit, @@big_tables;
 @@autocommit	@@big_tables
 1	1
 set global binlog_cache_size=100;
+Warnings:
+Warning	1292	Truncated incorrect binlog_cache_size value: '100'
 set bulk_insert_buffer_size=100;
 set character set cp1251_koi8;
 set character set default;
@@ -349,17 +353,27 @@ set global flush_time=100;
 set insert_id=1;
 set interactive_timeout=100;
 set join_buffer_size=100;
+Warnings:
+Warning	1292	Truncated incorrect join_buffer_size value: '100'
 set last_insert_id=1;
 set global local_infile=1;
 set long_query_time=100;
 set low_priority_updates=1;
 set max_allowed_packet=100;
+Warnings:
+Warning	1292	Truncated incorrect max_allowed_packet value: '100'
 set global max_binlog_cache_size=100;
+Warnings:
+Warning	1292	Truncated incorrect max_binlog_cache_size value: '100'
 set global max_binlog_size=100;
+Warnings:
+Warning	1292	Truncated incorrect max_binlog_size value: '100'
 set global max_connect_errors=100;
 set global max_connections=100;
 set global max_delayed_threads=100;
 set max_heap_table_size=100;
+Warnings:
+Warning	1292	Truncated incorrect max_heap_table_size value: '100'
 set max_join_size=100;
 set max_sort_length=100;
 set max_tmp_tables=100;
@@ -370,17 +384,25 @@ select @@max_user_connections;
 set global max_write_lock_count=100;
 set myisam_sort_buffer_size=100;
 set net_buffer_length=100;
+Warnings:
+Warning	1292	Truncated incorrect net_buffer_length value: '100'
 set net_read_timeout=100;
 set net_write_timeout=100;
 set global query_cache_limit=100;
 set global query_cache_size=100;
 set global query_cache_type=demand;
 set read_buffer_size=100;
+Warnings:
+Warning	1292	Truncated incorrect read_buffer_size value: '100'
 set read_rnd_buffer_size=100;
+Warnings:
+Warning	1292	Truncated incorrect read_rnd_buffer_size value: '100'
 set global rpl_recovery_rank=100;
 set global server_id=100;
 set global slow_launch_time=100;
 set sort_buffer_size=100;
+Warnings:
+Warning	1292	Truncated incorrect sort_buffer_size value: '100'
 set @@max_sp_recursion_depth=10;
 select @@max_sp_recursion_depth;
 @@max_sp_recursion_depth
@@ -420,6 +442,8 @@ set storage_engine=myisam;
 set global thread_cache_size=100;
 set timestamp=1, timestamp=default;
 set tmp_table_size=100;
+Warnings:
+Warning	1292	Truncated incorrect tmp_table_size value: '100'
 set tx_isolation="READ-COMMITTED";
 set wait_timeout=100;
 set log_warnings=1;
@@ -570,6 +594,8 @@ SHOW VARIABLES LIKE 'MYISAM_DATA_POINTER_SIZE';
 Variable_name	Value
 myisam_data_pointer_size	7
 SET GLOBAL table_cache=-1;
+Warnings:
+Warning	1292	Truncated incorrect table_cache value: '0'
 SHOW VARIABLES LIKE 'table_cache';
 Variable_name	Value
 table_cache	1