src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/arrays/NumberArrayData.java

*** 119,131 ****
          }
          return this;
      }
  
      @Override
!     public void shiftLeft(final int by) {
          System.arraycopy(array, by, array, 0, array.length - by);
      }
  
      @Override
      public ArrayData shiftRight(final int by) {
          final ArrayData newData = ensure(by + length() - 1);
          if (newData != this) {
--- 119,137 ----
          }
          return this;
      }
  
      @Override
!     public ArrayData shiftLeft(final int by) {
!         if (by >= length()) {
!             shrink(0);
!         } else {
              System.arraycopy(array, by, array, 0, array.length - by);
          }
+         setLength(Math.max(0, length() - by));
+         return this;
+     }
  
      @Override
      public ArrayData shiftRight(final int by) {
          final ArrayData newData = ensure(by + length() - 1);
          if (newData != this) {