Re: [dmarc-ietf] "psd=" tag early assignment

[Scott Kitterman <[e-mail]>]

On July 9, 2022 5:07:43 PM UTC, Alessandro Vesely <[e-mail]> wrote:
>On Fri 08/Jul/2022 22:07:09 +0200 John Levine wrote:
>>>> The description of the tree walk should be clear enough.
>>> 
>>> Yeah, /should/!  The very fact that you yourself changed your mind about how it works, without going into the hassle of explaining your reasoning, ...
>> 
>> Um, what?  Scott and I went through some rounds of debugging to be sure the tree walk handled some obscure edge cases in a reasonable way.  It was all on this very mailing list with examples.  I think what we have now is OK but if you find something in the tree walk that is unclear or gets an unreasonable result, let us know, preferably with a concrete example.
>
>
>I think I received all list messages (although I don't check against your weekly count) an I read all of them.  Perhaps I've been inattentive, but I don't recall the switch from stop on psd=y to continue on psd=y if it's the first lookup.  Any pointer?


I don't recall having changed this.  If you can check the previous draft revisions to see when it changed, maybe I could find it.  I'm confident that any changes to the way the tree walk works have been discussed on the list.

>> Having done that, I remind everyone for the umpteenth time that that the overwhelming majority of DMARC publishers and DMARC lookups will not see even one psd tag, much less more than one.  While I could sort of see the use of an appendix describing the normal sorts of DMARC records that real mail operators are likely to publish and evaluate, I cannot see any benefit in wasting yet more time on arcane PSD edge cases.
>
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>I agree, but I think developers will have to code for corner cases as well, won't they?  Telling programmers to just follow the spec, without trying to understand them seldom results in good code.


Yes, but I don't think it's that complicated.  I may be wrong, but I don't think any of the recent corner case discussions have raised any points that weren't already handled by the code I wrote based on what's in the draft.  I think the last time I had to change anything was when we ditched the reverse tree walk.

Scott K