src/java.base/share/classes/java/util/Collections.java

*** 457,467 ****
          int size = list.size();
          if (size < SHUFFLE_THRESHOLD || list instanceof RandomAccess) {
              for (int i=size; i>1; i--)
                  swap(list, i-1, rnd.nextInt(i));
          } else {
!             Object arr[] = list.toArray();
  
              // Shuffle array
              for (int i=size; i>1; i--)
                  swap(arr, i-1, rnd.nextInt(i));
  
--- 457,467 ----
          int size = list.size();
          if (size < SHUFFLE_THRESHOLD || list instanceof RandomAccess) {
              for (int i=size; i>1; i--)
                  swap(list, i-1, rnd.nextInt(i));
          } else {
!             Object[] arr = list.toArray();
  
              // Shuffle array
              for (int i=size; i>1; i--)
                  swap(arr, i-1, rnd.nextInt(i));