Re: [Qemu-devel] [PATCH] error: Fix error_report_err(), warn_report_err() hint printing

[Markus Armbruster]

Markus Armbruster <address@hidden> writes:

> Before the from qerror_report() to error_setg(), hints looked like
> this:
>
>     qerror_report(QERR_MACRO, ... arguments ...);
>     error_printf_unless_qmp(... hint ...);
>
> error_printf_unless_qmp() made perfect sense: it printed exactly when
> qerror_report() did.
>
> After the conversion to error_setg():
>
>     error_setg(errp, QERR_MACRO, ... arguments ...);
>     error_printf_unless_qmp(... hint ...);
>
> The "unless QMP part" still made some sense; in QMP context, the
> caller generally uses the error as QMP response instead of printing
> it.
>
> However, everything else is wrong.  If the caller handles the error,
> the hint gets printed anyway (unless QMP).  If the caller reports the
> error, the hint gets printed *before* the report (unless QMP) or not
> at all (if QMP).
>
> Commit 50b7b000c91 fixed this by making hints a member of Error.  It
> kept printing hints with error_printf_unless_qmp():
>
>      void error_report_err(Error *err)
>      {
>        error_report("%s", error_get_pretty(err));
>     +    if (err->hint) {
>     +        error_printf_unless_qmp("%s\n", err->hint->str);
>     +    }
>        error_free(err);
>      }
>
> This is wrong.  We should (and now can) print the hint exactly when we
> print the error.
>
> The mistake has since been copied to warn_report_err().
>
> Fix both to use error_printf().
>
> Reported-by: Vladimir Sementsov-Ogievskiy <address@hidden>
> Cc: Eric Blake <address@hidden>
> Signed-off-by: Markus Armbruster <address@hidden>

Queued.