Peter Eisentraut <peter_e@gmx.net> writes:
> And then, what is the supposed semantics of calling a nonstrict input
> function with NULL as the cstring value? InputFunctionCall() requires
> that the return value is null if and only if the input cstring was
> NULL, "but we'll call the input function anyway". Couldn't the call
> to InputFunctionCall() be scrapped altogether in the above case?
No. The point of this is to allow domain_in() to apply domain
constraint checks that might or might not throw error on null values.
I'm not sure whether the code you quote is getting this right in
all the branches, but the last case isn't useless.
regards, tom lane