Commit c8c416802 (#4144) introduced module-level renderedSegments state
to track interleaved text/tool components per assistant turn, but never
reset it when an adapter shrinks streamingMessage.content[] back to 0/1
at a provider sub-turn boundary within one assistant lifecycle (the
claude-code adapter does this). Consequence chain: the segment walker
finds the stale text-run entry at startIndex=0, calls updateContent on
it with the new (shrunk) message, and the in-place edit destroys the
prior sub-turn's visible text. New tool blocks at contentIndex=1 then
collide with stale registrations, causing visual ordering corruption.
hasToolsInTurn stays sticky-true and lastPinnedText never clears, so
the pinned "Working - Latest Output" mirror freezes on the pre-shrink
snapshot.
Track lastContentLength explicitly. On shrink, clear renderedSegments,
reset lastPinnedText, and reset lastProcessedContentIndex so the
walker treats the new sub-turn as fresh segments that append after
prior sub-turn children. Prior history stays rendered as frozen
components; pendingTools and the spinner border are untouched.
Adds two regression tests in chat-controller-ordering.test.ts: one
verifies prior sub-turn components are not overwritten and new tools
append in content[] order after a shrink, the other verifies the
pinned markdown updates from the first sub-turn's text to the second
sub-turn's text across a shrink boundary.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
03b7142400