wrong error: Variable name "i" already defined (check_syntax) [E]

[Ennowulff]

The following code leads to the error:
Variable name "i" already defined (check_syntax) [E]

CLASS zcl_demo DEFINITION.

  PUBLIC SECTION.
    METHODS test
      IMPORTING
        word1 TYPE string
        word2 TYPE string
  PROTECTED SECTION.
  PRIVATE SECTION.
ENDCLASS.

CLASS zcl_demo IMPLEMENTATION.
  METHOD text.

    DATA(word1_table) = VALUE string_table( FOR i = 0 WHILE i < strlen( word1 )
                                        ( substring( val = word1 off = i len = 1 ) ) ).
    DATA(word2_table) = VALUE string_table( FOR i = 0 WHILE i < strlen( word2 )
                                        ( substring( val = word2 off = i len = 1 ) ) ).
  ENDMETHOD.

ENDCLASS.

The second VALUE command uses the same local variable "i" what is accepted by the ABAP compiler.
But it leads to the error in exercism.

[larshp]

thanks, also see #202