Module line_ring 

Bounded, line-oriented scrollback buffer fed raw PTY chunks.

The PTY reader appends decoded chunks; this keeps the most recent capacity complete lines plus the in-flight (unterminated) partial line. Crucially it remembers what it had to throw away — older lines evicted once the ring filled, and bytes clipped off a pathologically long newline-less line — so LineRing::scrollback_notice can tell the caller their scrollback is incomplete instead of silently handing back a truncated view. Extracted from PtyShell so the ring logic is unit-testable without spawning a real shell.

Structs

LineRing

A ring of complete lines plus a pending partial line, with drop accounting.