From c4910709d98f6a6cb8b8182890abbdc45ce86b50 Mon Sep 17 00:00:00 2001
From: Kornel <kornel@cloudflare.com>
Date: Tue, 15 Jun 2021 12:24:04 +0100
Subject: [PATCH] Assertions

---
 src/filters.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/filters.rs b/src/filters.rs
index 0c4d50c0..8b85ca17 100644
--- a/src/filters.rs
+++ b/src/filters.rs
@@ -1,4 +1,6 @@
 pub fn filter_line(filter: u8, bpp: usize, data: &[u8], last_line: &[u8], buf: &mut Vec<u8>) {
+    assert!(data.len() >= bpp);
+    assert!(last_line.is_empty() || data.len() == last_line.len());
     buf.reserve(data.len());
     match filter {
         0 => {
@@ -17,6 +19,7 @@ pub fn filter_line(filter: u8, bpp: usize, data: &[u8], last_line: &[u8], buf: &
             if last_line.is_empty() {
                 buf.extend_from_slice(data);
             } else {
+                assert_eq!(data.len(), last_line.len());
                 buf.extend(
                     data.iter()
                         .zip(last_line.iter())
@@ -65,6 +68,7 @@ pub fn filter_line(filter: u8, bpp: usize, data: &[u8], last_line: &[u8], buf: &
 pub fn unfilter_line(filter: u8, bpp: usize, data: &[u8], last_line: &[u8], buf: &mut Vec<u8>) {
     buf.clear();
     buf.reserve(data.len());
+    assert!(data.len() >= bpp);
     assert_eq!(data.len(), last_line.len());
     match filter {
         0 => {