chore: Harden MJPEG frame parsing and stream startup - #2927
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## [12.1.2](v12.1.1...v12.1.2) (2026-07-30) ### Miscellaneous Chores * Harden MJPEG frame parsing and stream startup ([#2927](#2927)) ([36bf6a0](36bf6a0))
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🎉 This PR is included in version 12.1.2 🎉 The release is available on: Your semantic-release bot 📦🚀 |
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Summary
Backports fixes from appium/appium-uiautomator2-driver#1028,
which ported this driver's MJPEG helpers (#2915) and hardened them further. Applies
the same fixes here:
MjpegFrameParser#appendChunkno longer uses a stray JPEG SOI marker found in acontinuation chunk as the copy start offset. Since the chunk is continuing an
already-open frame, it always belongs there in full — a SOI marker inside it can
only belong to the next frame, so using it as the start truncated the tail of
the current frame.
MjpegFrameParser#emitFramenow pushes only the bytes actually written(
buffer.subarray(0, bytesWritten)) instead of the whole pre-allocated buffer,so a frame no longer leaks trailing zero bytes when
Content-Lengthoverstatesthe real frame size. Frame state is also reset after emitting, so a later stray
chunk can't be appended onto a buffer already pushed downstream.
MJpegStream#start()now rejects immediately if the connection closes beforeany frame arrives, instead of waiting out the full server timeout.
MJpegStream#start()now callsstop()before rethrowing on failure, so afailed start doesn't leak the underlying HTTP stream/pipes.
MjpegFrameParseris now exported so it can be unit tested directly.