m

src/lib.rs

@@ -391,7 +391,7 @@ impl Sam {
         if is_reverse(flag) {
             let len = ref_range.len();
             ref_range.end = (ref_pos as usize) - 1;
-            ref_range.start = ref_pos as usize + len;
+            ref_range.start = ref_pos as usize + len - 1;
         } else {
             let len = ref_range.len(); 
             ref_range.start = ref_pos as usize;