Fix zero-OptFlds report metadata leaking into process values

[masarray]

Field regression

ARSAS 1.6.31+a7e2f91 with ARIEC61850 e23b295 still showed initial StaticUrcb Event Log values such as bits(0000, ...), bits(FFFFFFFF...), and DPC bit strings under unrelated .stVal references. MMS validation moments later produced the correct scalar values.

Root cause

MmsReportFrameMapper.TryMapOptFldsDrivenReportValues rejected an IEC 61850 report when the mandatory OptFlds bit-string had all optional bits clear. Zero OptFlds is a valid report shape: inclusion follows immediately after RptID + OptFlds. Once rejected, the mapper could fall through to a raw AccessResult-by-index fallback, which paired report metadata (OptFlds/inclusion/reason) with DataSet members as if the metadata were process values.

This exactly explains the field pattern: zero OptFlds appeared as bits(0000, ...), the 36-member inclusion bitmap appeared as a long all-ones bit string, and later process DPC bit strings were shifted onto unrelated Boolean members.

Fix

• Treat zero OptFlds as a valid canonical report envelope.
• If a canonical RptID + OptFlds frame cannot be mapped strictly, quarantine it instead of heuristic/raw projection.
• Remove the raw AccessResult -> DataSet member fallback from the public process-value path.
• Require inclusion bit-string length to exactly equal the known DataSet member count.
• Correct reason-for-inclusion numbering: bit 0 reserved; bit 1 dchg; bit 2 qchg; bit 3 dupd; bit 4 integrity; bit 5 GI; bit 6 application-trigger.
• Preserve report header evidence on rejected frames while exposing zero process Values.

Regression coverage

Adds a field-shaped 36-member Digital DataSet report with zero OptFlds, full inclusion, mixed Boolean/DPC process values, and asserts that no report metadata leaks into projected Values. Also verifies malformed canonical frames are quarantined and reason bit 1 decodes as data-change.

No temporary patch workflow or script remains in the final branch.

[chatgpt-codex-connector]

You have reached your Codex usage limits for code reviews. You can see your limits in the Codex usage dashboard.
To continue using code reviews, you can upgrade your account or add credits to your account and enable them for code reviews in your settings.