Two confirmed bugs in the thinking/reasoning display:
1. reasoningText was initialized once when the SSE stream opened and never
reset between turns. On the done event, the last assistant message
received the union of every turn's reasoning. Now reset at both turn
boundaries: tool (alongside existing liveReasoningText reset) and
interim_assistant (the other turn boundary where prior reasoning closes).
2. ui.js renderMessages preferred m.reasoning (which could be corrupted by
bug 1) over m.reasoning_content (the clean per-turn value from the
backend). The fallback now reads m.reasoning_content || m.reasoning.
Both fixes are needed: bug 2 alone cannot cover providers that stream
reasoning events without populating reasoning_content on the final API
message.
Updated test_streaming_race_fix.py to scope its reconnect-accumulator
guard to the _wireSSE preamble only, since turn-boundary resets inside
event listeners are intentional and correct.
9 new regression tests in test_issue2565_reasoning_accumulation.py.
b3nw
160cd03c18
