BUG#9072 'Max_error_count' system variable cannot be set to zero

 - Chaned min value in mysqld.cc
 - Added testcase to warnings.test


mysql-test/r/warnings.result:
  Added testcase for testing max and min value of max_error_count
mysql-test/t/warnings.test:
  Added testcase for testing max and min value of max_error_count
sql/mysqld.cc:
  Change min value of max_error_count from 1 to 0

mysql-test/r/warnings.result

@@ -142,6 +142,25 @@ Warning	1265	Data truncated for column 'b' at row 10
 select @@warning_count;
 @@warning_count
 50
+set max_error_count=0;
+show variables like 'max_error_count';
+Variable_name	Value
+max_error_count	0
+update t1 set b='hi';
+Warnings:
+select @@warning_count;
+@@warning_count
+50
+show warnings;
+Level	Code	Message
+set max_error_count=65535;
+show variables like 'max_error_count';
+Variable_name	Value
+max_error_count	65535
+set max_error_count=10;
+show variables like 'max_error_count';
+Variable_name	Value
+max_error_count	10
 drop table t1;
 create table t1 (id int) engine=isam;
 Warnings:

mysql-test/t/warnings.test

@@ -97,6 +97,19 @@ update t1 set b=a;
 select @@warning_count;
 --enable_ps_protocol
 
+# Bug#9072
+set max_error_count=0;
+show variables like 'max_error_count';
+update t1 set b='hi';
+--disable_ps_protocol
+select @@warning_count;
+--enable_ps_protocol
+show warnings;
+set max_error_count=65535;
+show variables like 'max_error_count';
+set max_error_count=10;
+show variables like 'max_error_count';
+
 #
 # Test for handler type
 #

sql/mysqld.cc

@@ -5053,7 +5053,7 @@ The minimum value for this variable is 4096.",
    "Max number of errors/warnings to store for a statement.",
    (gptr*) &global_system_variables.max_error_count,
    (gptr*) &max_system_variables.max_error_count,
-   0, GET_ULONG, REQUIRED_ARG, DEFAULT_ERROR_COUNT, 1, 65535, 0, 1, 0},
+   0, GET_ULONG, REQUIRED_ARG, DEFAULT_ERROR_COUNT, 0, 65535, 0, 1, 0},
   {"max_heap_table_size", OPT_MAX_HEP_TABLE_SIZE,
    "Don't allow creation of heap tables bigger than this.",
    (gptr*) &global_system_variables.max_heap_table_size,