Re: log message in proto.c

On Tue, Sep 24, 2019 at 5:41 AM Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> src/backend/replication/logical/proto.c
> action = pq_getmsgbyte(in);
> if (action != 'N')
> elog(ERROR, "expected new tuple but got %d",
> action);
>
> "%d" in the above message should be "%c" because the type of
> the variable "action" is char? There are other log messages that
> "%c" is used for such variable, in proto.c. Seems the above is
> only message that "%d" is used for such variable.

The potential problem with using %c to print characters is that the
character might be a null byte or something else that ends up making
the log file invalid under the relevant encoding.

However, if the goal of using %d is to protect against such problems,
it has to be done consistently.

--
Robert Haas
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