[nGoline]

An obfuscated message began and ended with the marker repeated:

00023CD100023CD1wV4DTmkMQQGcaxcSAQdANo1t8...=x9Yz00023CD100023CD1

Cause

Not every line break — only blank lines. obfuscateMarkers replaced them with the marker alongside the armor header and footer, and armored output happens to carry a blank line immediately after the Version: header and another at the end, both sitting next to a real marker:

Line	Rule	Emits
-----BEGIN PGP MESSAGE-----	armor header	00023CD1
Version: BCPG v1.81	Version:/Comment:	nothing
(blank)	line.isBlank()	00023CD1 ←
wV4DTmk...	everything else	the line itself
-----END PGP MESSAGE-----	armor footer	00023CD1
(blank)	line.isBlank()	00023CD1 ←

Ordinary lines are joined with no separator, so the body was never affected — only the two ends.

Why it is worth fixing rather than tolerating

The setting's own description is "make messages harder to detect". A doubled sixteen-character hex run is a more distinctive signature than a single eight-character one, so the duplication worked against the feature it belonged to.

The fix

Blank lines are dropped, like the Version: header immediately above them. Nothing depended on them being marked: every use of the marker either tests for it at the start of a message or strips every occurrence, and deobfuscation discards all newlines and re-chunks the base64 from scratch, so the blank line's structural role is rebuilt rather than preserved.

Backward compatibility

Messages already sent carry the doubled markers and cannot be recalled. Deobfuscation removes every occurrence, so they still work — and there is a test pinning that, because it would be easy to tidy the deobfuscator later and silently break every message sent before this release.

Tests

Seven, covering what the feature emits as well as whether it round trips:

• the marker is not repeated back to back
• exactly one marker at each end
• no -----BEGIN, -----END or BCPG version string survives
• the payload and its checksum are untouched
• obfuscate → deobfuscate returns armor whose body matches byte for byte
• messages in the old doubled format still deobfuscate
• an obfuscated message is still recognised as one, since decryptMessage and the notification listener both detect by leading marker

Mutation-checked: restoring the old behaviour fails two of them. 63 tests total, lint clean.

obfuscateMarkers becomes internal + @VisibleForTesting, matching deobfuscateMarkers.

Note

No version bump here — that goes in the release PR when you cut the next version, same as 0.4 and 0.5.