FA-52555 / Raster memory layout / Member archive

Variable Scanline Packets: Packet extent excludes terminator or all framing · case 05

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

Member previewVariant 5 · 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": 94, "directory_bytes": 20, "directory_entry": 45, "packet_origins": [65, 72, 74, 79, 82], "packet_sizes": [7, 2, 5, 3, 12], "payload_end": 72, "payload_start": 67, "relative_offsets": [0, 7, 9, 14, 17], "rows": 5, "terminator": 72}`	`{"allocation_end": 99, "directory_bytes": 20, "directory_entry": 45, "packet_origins": [65, 73, 76, 82, 86], "packet_sizes": [8, 3, 6, 4, 13], "payload_end": 72, "payload_start": 67, "relative_offsets": [0, 8, 11, 17, 21], "rows": 5, "terminator": 72}`	Failed

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