From 0d612fd3c23b8ec7f9976ea39c86fb803de40c9e Mon Sep 17 00:00:00 2001
From: Ivan Smirnov <i.s.smirnov@gmail.com>
Date: Wed, 1 Dec 2021 17:13:50 +0000
Subject: [PATCH] Fix: check decode buffer end after the run opcode

---
 src/decode.rs | 7 ++-----
 src/error.rs  | 4 ++++
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/decode.rs b/src/decode.rs
index ba02565..6823595 100644
--- a/src/decode.rs
+++ b/src/decode.rs
@@ -58,15 +58,12 @@ where
     let mut run = 0_u16;
 
     for px_out in pixels.iter_mut() {
-        if unlikely(!buf.within_bounds()) {
-            break;
-        }
-
-        // TODO: check for safety that ReadBuf is not over yet
         if run != 0 {
             run -= 1;
             *px_out = px;
             continue;
+        } else if unlikely(!buf.within_bounds()) {
+            return Err(Error::UnexpectedBufferEnd);
         }
 
         let b1 = buf.read();
diff --git a/src/error.rs b/src/error.rs
index 58a5b4f..b1f8e5b 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -12,6 +12,7 @@ pub enum Error {
     InputBufferTooSmall { size: usize, required: usize },
     OutputBufferTooSmall { size: usize, required: usize },
     InvalidMagic { magic: u32 },
+    UnexpectedBufferEnd,
     // TODO: invalid colorspace
 }
 
@@ -38,6 +39,9 @@ impl Display for Error {
             Self::InvalidMagic { magic } => {
                 write!(f, "invalid magic: expected {:?}, got {:?}", QOI_MAGIC, magic)
             }
+            Self::UnexpectedBufferEnd => {
+                write!(f, "unexpected input buffer end while decoding")
+            }
         }
     }
 }