FA-52573 / Raster memory layout / Member archive

Variable Scanline Packets: Payload begins at tag or skips first encoded byte · case 03

The returned physical layout descriptor disagrees with the declared buffer mapping at payload_start.

Member previewVariant 3 · 3 implementations · 6 checks per implementation

Case contract

Each scanline is a packet with a two-byte tag, a four-byte absolute-offset directory entry, and a caller-specified encoded payload length. The directory precedes packet bytes; a trailing one-byte terminator follows each packet. Return the named intermediate layout descriptor and final address fields; all quantities are integer byte offsets unless explicitly stated.

Why this case matters

Offline raster resource, upload, readback, and storage-layout regression model.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
layout fixture 1	`{"allocation_end": 75, "directory_bytes": 20, "directory_entry": 27, "packet_origins": [47, 53, 56, 62, 66], "packet_sizes": [6, 3, 6, 4, 9], "payload_end": 50, "payload_start": 47, "relative_offsets": [0, 6, 9, 15, 19], "rows": 5, "terminator": 50}`	`{"allocation_end": 75, "directory_bytes": 20, "directory_entry": 27, "packet_origins": [47, 53, 56, 62, 66], "packet_sizes": [6, 3, 6, 4, 9], "payload_end": 52, "payload_start": 49, "relative_offsets": [0, 6, 9, 15, 19], "rows": 5, "terminator": 52}`	Failed

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