fix: Avoid out-of-bounds indexing

This was found by QuickCheck.

src/compress.rs

@@ -140,7 +140,7 @@ pub fn compress(data: &[u8]) -> LzfResult<Vec<u8>> {
             current_offset += 1;
         } else {
             /* one more literal byte we must copy */
-            if current_offset >= out_buf_len {
+            if out_len >= out_buf_len as i32 {
                 return Err(LzfError::NoCompressionPossible);
             }
 
@@ -252,3 +252,10 @@ fn test_alice_wonderland_both() {
 
     assert_eq!(&compressed[..], &c_compressed[..]);
 }
+
+#[test]
+fn quickcheck_found_bug() {
+    let inp = vec![0, 0, 0, 0, 1, 0, 0, 2, 0, 0, 3, 0, 0, 4, 0, 1, 1, 0, 1, 2, 0, 1, 3, 0, 1, 4, 0, 0, 5, 0, 0, 6, 0, 0, 7, 0, 0, 8, 0, 0, 9, 0, 0, 10, 0, 0, 11, 0, 1, 5, 0, 1, 6, 0, 1, 7, 0, 1, 8, 0, 1, 9, 0, 1, 10, 0, 0];
+
+    assert_eq!(LzfError::NoCompressionPossible, compress(&inp).unwrap_err());
+}