Connector stmt sends 'close' command if stmt handle was never used

If application inits stmt handle, but then closes it without use, C/C sends redundant 'close' command to the server for the stmtid==0. Application has to call mysql_stmt_close in this case, as it needs to free allocated stmt handle memory, anyway.
I am not sure if this is a bug or an improvement. But this scenario happens in C/ODBC quite often, as it allocates stmt along with ODBC statement handle allocation, and I'd prefer not to fix this in GA version.