[exim] SRS example in spec

Good morning,

the SRS example in the spec features three routers:
8X-------------------------------------------------------------------
outbound:
[dnslookup router, choose srs-encoding transport when necessary]

inbound_srs:
[try to SRS-decode incoming bounce and redirect to new adddress on
success]

inbound_srs_failure:
  driver =    redirect
  senders =   :
  domains =   +my_domains
  # detect inbound bounces which look SRS'd but are invalid
  condition = ${if inbound_srs {$local_part} {}}
  allow_fail
  data =      :fail: Invalid SRS recipient address

#... further routers here
8X-------------------------------------------------------------------

I do not get the third one:
Afaict comment and code do not match. The router fails all bounces where
inbound_srs{} fails, not only the ones that "look SRS'd".

Why is it necessary? The inbound_srs-router will have handled the
valid cases so whatever we get now can be handled by the regular
routers. - SRS0=notvalid@??? will be handled by the same logic as
any other invalid-localpart@???.

I am sure I am missing something.

TIA, cu Andreas
--
`What a good friend you are to him, Dr. Maturin. His other friends are
so grateful to you.'
`I sew his ears on from time to time, sure'

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