Tom Lane <t...@sss.pgh.pa.us> writes: > Gregory Stark <st...@enterprisedb.com> writes: >> Maybe I'm missing something but I don't understand how this fixes the >> problem. >> s is a "char*" so type punning it to an unsigned char * before dereferencing >> it is really the same as casting it to unsigned char directly > > No, it isn't. If char is signed then you'll get quite different results > from a high-bit-set byte value, because sign extension will happen > before the value is reinterpreted as unsigned.
What I wrote is correct. There's no sign extension if you're casting from signed char to unsigned char since there's no extension. I really think he should just change all the "unsigned int" into "unsigned char" and not do the type punning with pointer casts. That's just evil. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com Ask me about EnterpriseDB's Slony Replication support! -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
