_decode_nai (decode.py) only treated an all-0xFF record as empty.
A record that is a lone identity tag, or a tag with a zero-length
value (e.g. 80 00 + FF erase filler — a standard unused EF_IMPU
record) slipped through to an ascii fallback and rendered as garbage
text (the "Text: �" artifact).
- Treat a lone tag (80 / 81) or tag+zero-length-value (80 00 / 81 00)
as empty.
- Only decode the TLV *value* bytes (UTF-8); never feed the TLV header
or trailing FF filler to the text decoder. Drop the fragile
raw.rstrip(...).decode('ascii','replace') fallback.
Tests: +4 (empty 80 00+FF record, all-FF, real SIP URI, lone tag).
Backend-only; stays on 1.22.0.
catarrh
e4ac80fb34