JSON_VALID accepts a number with an empty exponent ('1e') inside arrays and objects, but not at the top level

Reproduced on 10.11.19 (debug build):

SELECT JSON_VALID('1e'), JSON_VALID('[1e]'), JSON_VALID('{"a":1e}'),

       JSON_VALID('[1e+]');

-- 0  1  1  1

The number scanner accepts an exponent with no digits when another token follows it. Expected: all four are invalid (0). JSON_VALUE('[1e]', '$[0]') also returns the text '1e' as if it were a value.