`pfUI/modules/autoshift.lua:45` answers `ERR_CANT_INTERACT_SHAPESHIFTED` with
if IsMounted() then Dismount() elseif GetShapeshiftFormID() ~= 0 then CancelShapeshiftForm() end
and grom's 2026-11-05 log carries `attempt to call global 'Dismount' (a nil value)` from
exactly there. That is a port written against verbs this client does not have, with a
comment claiming both "do their own engine-side aura scan and send the cancel packet
directly" — which was the design and not the state.
Both were on `compat/classic_api/state.rs`'s not-built list for a reason that turned out to
be answerable. Each needs the SPELL ID behind a state the engine reports as a flag
(`UNIT_FIELD_MOUNTDISPLAYID`) or an index (`SelfMovement::shapeshift_form`), because
`CMSG_CANCEL_AURA` carries an id and nothing else; and the player's aura list carries spell
ids and nothing about what each aura IS. The missing half was one derivation —
`EffectApplyAuraName` 78 (`SPELL_AURA_MOUNTED`) and 36 (`SPELL_AURA_MOD_SHAPESHIFT`), now
`SpellDisplay::mount_aura`/`shapeshift_aura` and two fields on `AuraState` beside
`channeled`, which the feed derives the same way from the same row it already reads.
Each verb is then the aura it names cancelled by id, which is what the reference's own
right-click on the buff does. Neither is gated on `aura::cancel_authorized`, unlike
`CancelPlayerBuff`: that gate is the reference's check inside THAT verb, this is not that
verb, the server makes its own decision about a cancel it is sent, and a mount whose aura
is not flagged `AFLAG_CANCELABLE` would otherwise be undismountable with no way to tell
why.
Allowlisted in `reference_surface` with the reason, as the four taint globals were: 1.12
has no verb for this because 1.12's player has the buff icon under the cursor, and an addon
reacting to an error message has neither an icon nor a cursor.
Verified: `dismount_and_cancel_form_each_cancel_their_own_aura_by_id` seats a plain buff, a
form and a mount in one list and asserts each verb finds its own id past the others, and
that neither fires with nothing to cancel. benilla-ui 2128/0, benilla-app at its recorded
baseline.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SgstFWtn1RxEJ5kVrpgYwn
gromandClaude Opus 5
a7a54c6d02