On Thu, Jul 02, 2026 at 04:07:07AM -0400, Jeff King wrote:

The flag handling could be removed if the hash-discard function were
idempotent. This could be done easily-ish by having the underlying
hash functions (like the ones in sha256/openssl.h) set the context
pointer to NULL after free-ing. But it's something that every platform
implementation would have to remember to do, and the benefit for the
callers is not that huge (it would let us shave a few lines here and
probably in a few other spots).

This answers an earlier question of mine. It would indeed be great if it
was idempotent -- I've been bitten by interfaces like this once too
much, where you have to be very careful to manage the lifetime of a
specific object. The prime example of this are (were? I don't quite
recall whether we fixed that interface) reference transactions, and that
caused a bunch of bugs in the past.

Patrick