Fix handling of empty slice in Instructions

Kixunil · tcharding · web-flow · commit 2c28d3b44802 · 2022-04-21T19:14:30.000+02:00
The code would've taken one element when an empty slice was requested.

Co-authored-by: Tobin C. Harding &lt;me@tobin.cc&gt;
diff --git a/src/blockdata/script.rs b/src/blockdata/script.rs
@@ -746,7 +746,10 @@ impl<'a> Instructions<'a> {
     fn take_slice_or_kill(&mut self, len: usize) -> Result<&'a [u8], Error> {
         if self.data.len() >= len {
             let slice = &self.data.as_slice()[..len];
-            self.data.nth(len.max(1) - 1);
+            if len > 0 {
+                self.data.nth(len - 1);
+            }
+
             Ok(slice)
         } else {
             self.kill();
