Re: minor smgr code cleanup

Neil Conway <neilc(at)samurai(dot)com> writes:
> bool
> IsReservedName(const char *name)
> {
> ! /* ugly coding for speed */
> ! return (name[0] == 'p' &&
> ! name[1] == 'g' &&
> ! name[2] == '_');
> }
> --- 160,178 ----
> bool
> IsReservedName(const char *name)
> {
> ! return strncmp(name, "pg_", 3);
> }

This change is actually wrong (backwards), no? You want a true result
on equality.

In any case I don't think this is a step forward in readability, and it
also poses a portability risk. You should always write such tests as

return strncmp(name, "pg_", 3) == 0;

(or != 0 as appropriate). Pretending that the result of strcmp is a
bool is a type pun, and one that can rise up to bite you. In the case
at hand, strncmp is allowed to return (say) 256 to indicate a nonzero
result --- which would be lost when the value is squeezed into a bool
(char). See the archives; we've had at least one bug of this ilk.

regards, tom lane