On Mon, Aug 15, 2022 at 1:17 AM Tomas Vondra <tomas.von...@enterprisedb.com> wrote: > > Hi, > > while experimenting with logical messages, I ran into this assert in > logicalmsg_desc: > > Assert(prefix[xlrec->prefix_size] != '\0'); > > This seems to be incorrect, because LogLogicalMessage does this: > > xlrec.prefix_size = strlen(prefix) + 1; > > So prefix_size includes the null byte, so the assert points out at the > first payload byte. And of course, the check should be "==" because we > expect the byte to be \0, not the other way around. > > It's pretty simple to make this crash by writing a logical message where > the first payload byte is \0, e.g. like this: > > select pg_logical_emit_message(true, 'a'::text, '\x00'::bytea); > > and then running pg_waldump on the WAL segment. > > Attached is a patch addressing this. This was added in 14, so we should > backpatch to that version.
+1 The patch looks good to me. Regards, -- Masahiko Sawada EDB: https://www.enterprisedb.com/
