# HG changeset patch
# User Michael Johnson <mjohnson@ociaw.com>
# Date 1606544782 21600
#      Sat Nov 28 00:26:22 2020 -0600
# Node ID 90c6f2d5a313159caf19b319acbd77202e6b0bdf
# Parent  e16488eaeb6f488d4d13d6bc6e89cd26c4ba6b50
Fix arithmetic overflow exception when reading ChaCha position

diff --git a/src/RandN/Rngs/ChaCha.cs b/src/RandN/Rngs/ChaCha.cs
--- a/src/RandN/Rngs/ChaCha.cs
+++ b/src/RandN/Rngs/ChaCha.cs
@@ -37,7 +37,7 @@
             // bits of the counter to the word index, so that it becomes 6 bits.
             get
             {
-                var block = (_blockBuffer.BlockCounter << 2) + (UInt64)(_blockBuffer.Index >> 4);
+                var block = unchecked((_blockBuffer.BlockCounter << 2) + (UInt64)(_blockBuffer.Index >> 4));
                 var word = (UInt32)(_blockBuffer.Index & 0b1111);
                 return new Counter(block, word);
             }