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.


client/mysql.cc:
  correct maxima in options array
client/mysqltest.c:
  adjust minimum for "sleep" option so default value is no longer
  out of bounds.
include/m_string.h:
  ullstr() - the unsigned brother of llstr()
include/my_getopt.h:
  Flag if we bounded the value (that is, correct anything aside from
  making value a multiple of block-size)
mysql-test/r/delayed.result:
  We throw a warning now when we adjust out of range parameters.
mysql-test/r/index_merge.result:
  We throw a warning now when we adjust out of range parameters.
mysql-test/r/innodb.result:
  We throw a warning now when we adjust out of range parameters.
mysql-test/r/innodb_mysql.result:
  We throw a warning now when we adjust out of range parameters.
mysql-test/r/key_cache.result:
  We throw a warning now when we adjust out of range parameters.
mysql-test/r/packet.result:
  We throw a warning now when we adjust out of range parameters.
mysql-test/r/ps.result:
  We throw a warning now when we adjust out of range parameters.
mysql-test/r/subselect.result:
  We throw a warning now when we adjust out of range parameters.
mysql-test/r/type_bit.result:
  We throw a warning now when we adjust out of range parameters.
mysql-test/r/type_bit_innodb.result:
  We throw a warning now when we adjust out of range parameters.
mysql-test/r/variables.result:
  correct results: bounds and step apply to variables' default values, too
mysql-test/t/variables.test:
  correct results: bounds and step apply to variables' default values, too
mysys/my_getopt.c:
  - apply bounds/step to default values of variables (based on work by serg)
  - print complaints about incorrect values for variables (truncation etc.,
    by requestion of consulting)
  - if no lower maximum is specified in variable definition, bound unsigned
    values at their maximum to prevent wrap-around
  - some calls to error_reporter had a \n, some didn't. remove \n from calls,
    let reporter-function handle it, so the default reporter behaves like that
    in mysqld
sql/mysql_priv.h:
  correct RANGE_ALLOC_BLOCK_SIZE (cleared with monty)
sql/mysqld.cc:
  correct maxima to correct data-type.
  correct minima where higher than default.
  correct range-alloc-block-size.
  correct inno variables so GET_* corresponds to actual variable's type.
sql/set_var.cc:
  When the new value for a variable is out of bounds, we'll send the
  client a warning (but not if the value was simply not a multiple of
  'blocksize').  sys_var_thd_ulong had this, sys_var_long_ptr_global
  didn't; broken out and streamlined to avoid duplication of code.
strings/llstr.c:
  ullstr() - the unsigned brother of llstr()

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