[log4perl-devel] invoking threshold() leaves appender data inconsistent

[Rob R. <Rob...@cl...>]

After plunking (actually, single-stepping in the debugger) around the
marvel of appender wrappers, appenders, closures, levels, thresholds,
and priorities that is Log4perl, I noticed the following.

As the Log4perl doc says, under "Access Defined Appenders":

"The previously mentioned method appender_by_name() returns a reference
to the real appender object. If you want access to the wrapper class
(e.g. if you want to modify the appender's threshold), use the hash
$Log::Log4perl::Logger::APPENDER_BY_NAME{...} instead, which holds
references to all appender wrapper objects."

Okay.  But when your application does:

  my $wrapper = $Log::Log4perl::Logger::APPENDER_BY_NAME{'somename'};
  $wrapper->threshold ('INFO');

what you get is the wrapper object's "level" field set to the... um,
priority of the 'INFO' level you passed in.  And that works, as
subsequently the appender does not log anything of higher... um, or
maybe lower, level... um, priority than INFO.  Yeah, that's it.

But it does leave the actual appender object's "Threshold" field
unchanged.  So if that field were already 'DEBUG', what you get is a
wrapper saying one thing about level, while it contains an appender
saying another thing about Threshold.

The effect turns out correct, but only because the appender's
"Threshold" is actually the wrapper's "level", and the two values need
not agree, since one of them seems to be ignored past initialization.
Ugh.

In the end, it seems like the threshold() routine ought to set (or
perhaps just delete) the appender's Threshold field when it sets the
wrapper's level field.

==========
Rob Retter