AW: [HACKERS] to_char() dumps core

[Zeugswetter Andreas SB]

> (Also, if you do want to check for a NULL input in current sources,
> looking for a NULL pointer is the wrong way to code it anyway;
> PG_ARGISNULL(n) is the right way.)

For pass by reference datatypes setting the reference to a null pointer
for a NULL value imho would be a fine thing in addition to the indicator, 
no ?

Andreas