Re: PATCH: S/390: don't try to read zero bytes

[Andrew Cagney <ac131313 at cygnus dot com>]

> Andrew Cagney <ac131313@cygnus.com> writes:
> 
>> > 2001-12-20  Jim Blandy  <jimb@redhat.com>
>> > 
>> > * s390-tdep.c (s390_readinstruction): Don't call
>> > info->read_memory_func to read zero bytes.  Some targets'
>> > xfer_memory functions can't cope with that.
>> > 
> 
>> 
>> 
>> Jim, which?
>> 
>> While slightly stupid, the target should be able to handle that.
> 
> 
> Oh, wait, I understand now.
> 
> A target's to_xfer_memory function is supposed to return the number of
> bytes transferred, or zero if it can't transfer the bytes.  If you
> make a zero-length request, there's no way for it to indicate success.
> D'oh!


Can you file a CR against this stupidity?  I'll add it to my list of 
things to untangle.

Andrew