The two discovery-path libplctag tags (@tags symbol-list enumerator, @udt
template reader) still passed the bare Gateway host, so a browse against a
device authored on a non-default port silently browsed whatever answers on
44818 — #534's defect surviving in its discovery half. Both sites now consume
AbCipTagCreateParams.LibplctagGateway, with the Tag construction extracted
into internal static builders so the seam is unit-assertable (the #534 tests
pinned the property's composition but nothing pinned each site's consumption,
which is exactly how these two survived).
New guard: LibplctagGatewayConsumptionGuardTests scans both AB drivers'
sources and fails on any libplctag Tag built from the bare Gateway, so a
future call site cannot reintroduce the silent 44818 redirect.
Live-gated against the fixture host: browse of ab://10.100.0.35:44818
returns the nine-tag symbol table; browse of ab://10.100.0.35:44999 (nothing
listening — the issue's exact repro) now fails ErrorTimeout where it
previously returned the 44818 fixture's table.
Closes#539.
Claude-Session: https://claude.ai/code/session_014WNM4vjoVksyyBraTXSZE1
Joseph Doherty
97a837c147