diff --git a/rust/hg-core/src/utils.rs b/rust/hg-core/src/utils.rs
--- a/rust/hg-core/src/utils.rs
+++ b/rust/hg-core/src/utils.rs
@@ -18,8 +18,7 @@
 where
     T: Clone + PartialEq,
 {
-    assert_eq!(from.len(), to.len());
-    if buf.len() < from.len() {
+    if buf.len() < from.len() || from.len() != to.len() {
         return;
     }
     for i in 0..=buf.len() - from.len() {