during udf initialization. The bug is spotted while working on Bug 12713.

If a user-defined function was used in a SELECT statement, and an
error would occur during UDF initialization, this error would not terminate
execution of the SELECT, but rather would be converted to a warning.

The fix is to use a stack buffer to store the message from udf_init instead
of private my_error() buffer.


mysql-test/r/udf.result:
  Update the result to reflect the fix for Bug#32007 select udf_function() 
  doesn't return an error if error during udf initialization
mysql-test/t/udf.test:
  Update the test to reflect the fix for Bug #32007 select udf_function() 
  doesn't return an error if error during udf initialization
sql/item_func.cc:
  A fix for Bug#32007.
  
  net.last_error buffer was used to store the temporary message from udf_init.
  Then, when my_error() was called, net.last_error was not empty so 
  my_error() would conclude that there is already an error in the error stack, 
  and not "overwrite" it.
  However, thd->net.report_error was not set, so the the 
  SELECT was not aborted.
  
  The fix is to use a stack buffer instead of thd->net.last_error
  to store the message from udf_init. The message will end up in
  thd->net.last_error anyway after a call to my_error.