zstd/doc/decompressor_accepted_invalid_data.md

Decompressor Accepted Invalid Data

This document describes the behavior of the reference decompressor in cases where it accepts an invalid frame instead of reporting an error.

Zero offsets converted to 1

If a sequence is decoded with literals_length = 0 and offset_value = 3 while Repeated_Offset_1 = 1, the computed offset will be 0, which is invalid.

The reference decompressor will process this case as if the computed offset was 1, including inserting 1 into the repeated offset list.