From: elasota <1137273+elasota@users.noreply.github.com>
Date: Tue, 2 Apr 2024 00:13:18 +0000 (-0400)
Subject: Specify that decoders may reject non-zero probabilities for larger offset codes than... 
X-Git-Tag: v1.5.7^2~86^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F4013%2Fhead;p=thirdparty%2Fzstd.git

Specify that decoders may reject non-zero probabilities for larger offset codes than supported by the implementation
---

diff --git a/doc/zstd_compression_format.md b/doc/zstd_compression_format.md
index 7955dae4a..8a60e56df 100644
--- a/doc/zstd_compression_format.md
+++ b/doc/zstd_compression_format.md
@@ -1129,7 +1129,10 @@ If the last symbol makes cumulated total go above `1 << Accuracy_Log`,
 distribution is considered corrupted.
 If this process results in a non-zero probability for a value outside of the
 valid range of values that the FSE table is defined for, even if that value is
-not used, then the data is considered corrupted.
+not used, then the data is considered corrupted.  In the case of offset codes,
+a decoder implementation may reject a frame containing a non-zero probability
+for an offset code larger than the largest offset code supported by the decoder
+implementation.
 
 Then the decoder can tell how many bytes were used in this process,
 and how many symbols are present.