From f21463d5f4f695332c7db27cd07e6200fd258075 Mon Sep 17 00:00:00 2001
From: Christian Schwarz <cmrs@cmrs.io>
Date: Sat, 29 Jul 2023 14:15:02 +0200
Subject: [PATCH] handle empty ranges in BitSlice::copy_within

resolves #236
---
 src/slice/api.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/slice/api.rs b/src/slice/api.rs
index 6ac0de00..00208967 100644
--- a/src/slice/api.rs
+++ b/src/slice/api.rs
@@ -2229,6 +2229,12 @@ where
 	where R: RangeExt<usize> {
 		let len = self.len();
 		let src = src.normalize(0, len);
+		// prevent the asserts below from failing for empty ranges
+		if src.start == src.end {
+			assert!(src.start <= len, "range start index {} is out of bounds for bit-slice of length {}", src.start, len);
+			assert!(dest <= len, "index {} is out of bounds for bit-slice of length {}", dest, len);
+			return;
+		}
 		self.assert_in_bounds(src.start, 0 .. len);
 		self.assert_in_bounds(src.end, 0 ..= len);
 		self.assert_in_bounds(dest, 0 .. len);