2 commits

Author	SHA1	Message	Date
Daisuke Maki	886f02bdee	fix data race in Source.linesInRange under in-place compaction ... In-place compaction in Append overwrites and then clears positions in the backing array. linesInRange returned a slice aliased into that array and released the read lock before the caller iterated it, so a concurrent compaction could nil out the caller's view (panic on DisplayString()) and trip the race detector. Return a copy. Add a -race regression test that pins the contract.	2026-06-04 10:14:55 +09:00
Daisuke Maki	ac77b9f2ff	amortize capped Source.Append to O(1)	2026-06-04 07:54:04 +09:00