Hi, Sanja! The idea of the fix is correct. See a couple of comments below. On Mar 14, sanja@askmonty.org wrote:

message: MDEV-4272 fix.

Incorrect NULL value handling in Item_func_conv_charset fixed.

=== modified file 'sql/item_strfunc.cc' --- a/sql/item_strfunc.cc 2013-01-28 12:36:05 +0000 +++ b/sql/item_strfunc.cc 2013-03-14 13:22:32 +0000 @@ -2987,7 +2987,7 @@ String *Item_func_conv_charset::val_str( return null_value ? 0 : &str_value; String *arg= args[0]->val_str(str); uint dummy_errors; - if (!arg) + if (!arg || args[0]->null_value)

it's redundant. One of these conditions is enough, no need to check both.

{ null_value=1; return 0;

=== modified file 'sql/item_strfunc.h' --- a/sql/item_strfunc.h 2013-01-15 18:07:46 +0000 +++ b/sql/item_strfunc.h 2013-03-14 13:22:32 +0000 @@ -859,25 +859,45 @@ public: { if (args[0]->result_type() == STRING_RESULT) return Item_str_func::val_int(); - return args[0]->val_int(); + { + longlong res= args[0]->val_int(); + if ((null_value= args[0]->null_value)) + return 0; + return res; + }

Why did you add an extra pair of curly brackets? it's also redundant. Regards, Sergei