resumeStream duplicates the previous assistant message: streaming state is seeded from the last message, then the start chunk renames its id and breaks the repl

Important limitations

• This may be one public report, not widespread demand.
• Current independent report count: 1.
• This is currently a single independent report. It has not passed clustering or human review as a verified signal.
• No market size, willingness to pay, competition, or trend claims are inferred here.

What was reported

Who is affected

Frontend application developer

Job to be done

Run tests reliably

Workflow

Added a chat regression test verifying a complete resumed stream preserves the previous assistant response and appends only the newly resumed response.

Desired outcome

Resuming should not clone an unrelated assistant message. Either seed a fresh message on the `resume-stream` trigger (the replay is complete from chunk 0, so there is nothing to continue), or keep the replace-vs-append decision stable across the `start` chunk's id rename. Related but distinct: #13160 covers a replay starting mid-text-part (missing `activeTextParts`); this issue happens with a complete replay.

Severity

Not enough evidence yet.

Urgency

Not enough evidence yet.

Evidence indicators

What would upgrade this

• Additional independent reports from distinct communities or authors.
• Human clustering into a review signal, then explicit publication approval.
• Counter-evidence review and durable original-source verification.

Original source

Open the original public report