bun

Summary Fixes / client response streams hanging under high concurrency when responses have delayed chunks (e.g. AWS SDK S3 downloads) Adds proper backpressure handling to — pauses reading from the ReadableStream when the Node.js Readable buffer is full, resumes when is called Avoids calling on normal stream completion (uses instead) Test plan [x] New regression test: — 20 workers × 50 iterations with chunked delayed responses [x] Verified regression test times out (hangs) with system bun, passes with fix [x] Original reproduction script (50 workers × 200 iterations = 10,000 requests) completes all downloads with fix [x] — 77 pass (1 pre-existing proxy failure) [x] — 3 pass [x] — 2 pass Closes #27557 🤖 Generated with Claude Code

Summary Fix in the REPL to properly handle multi-line content recalled from history by tracking rendered lines, clearing them before redraw, and correctly positioning the cursor Fix history file persistence so multi-line entries aren't corrupted across sessions (uses ASCII Record Separator delimiter with backward compatibility for legacy files) Closes #27560 What was the bug? When multi-line code (e.g., ) was entered in the REPL and then recalled via the up arrow key, each keystroke (backspace, cursor movement, etc.) caused the entire multi-line content to be reprinted on screen, creating duplicated output that grew with each keypress. Root cause: only cleared one terminal line () before redrawing, but the buffer from multi-line history entries contained embedded characters that spanned multiple terminal lines. Each redraw would output new lines below without clearing the previous rendering. Secondary issue: The history file used as both the entry delimiter and internal line separator, so multi-line entries were fragmented into separate entries when saved and reloaded. Changes : Added multi-line rendering path that moves cursor up to clear previously rendered extra lines, writes continuation prompts () for each line, and properly positions the cursor within multi-line content : New helper that moves the cursor past multi-line content before Enter/Ctrl+C so output appears below it /**: Uses ASCII Record Separator () as entry delimiter when multi-line entries exist, with backward compatibility for legacy newline-delimited files : New state field tracking extra terminal lines from the previous render Added regression test for recalling multi-line history and editing it Test plan [x] All 106 existing REPL tests pass [x] New regression test passes with debug build [ ] Manual testing: enter multi-line code in REPL, press up arrow, press backspace — display should update cleanly without duplicating content 🤖 Generated with Claude Code