From: Kostya Shishkov <kostya.shishkov@gmail.com>
Date: Sun, 26 Apr 2020 12:14:31 +0000 (+0200)
Subject: core/io: fix reading escape bits past end in codebook
X-Git-Url: https://git.nihav.org/?a=commitdiff_plain;h=0bbe433e917f4253df8536bf5e583b07f71bf6c0;p=nihav.git

core/io: fix reading escape bits past end in codebook
---

diff --git a/nihav-core/src/io/codebook.rs b/nihav-core/src/io/codebook.rs
index 553f2f9..d835ce3 100644
--- a/nihav-core/src/io/codebook.rs
+++ b/nihav-core/src/io/codebook.rs
@@ -370,10 +370,10 @@ impl<'a, S: Copy> CodebookReader<S> for BitReader<'a> {
             let bits = cb.table[lut_idx] & 0x7F;
             esc  = (cb.table[lut_idx] & 0x80) != 0;
             idx  = (cb.table[lut_idx] >> 8) as usize;
-            if (bits as isize) > self.left() {
+            let skip_bits = if esc { u32::from(lut_bits) } else { bits };
+            if (skip_bits as isize) > self.left() {
                 return Err(CodebookError::InvalidCode);
             }
-            let skip_bits = if esc { u32::from(lut_bits) } else { bits };
             self.skip(skip_bits as u32).unwrap();
             lut_bits = bits as u8;
         }