COUNTA counts wrong if called with multiple arguments

[SlowFox71]

COUNTA(B1,B2,B3,B4) should count each cell which is not NULL. In this case, however, the function is passed an argument

array(4) {
    [0] => NULL
    [1] => NULL
    [2] => NULL
    [3[ => NULL
}

and when examined, each index is treated as not a cell value by Functions::isCellValue() (because it lacks two dots) and thus counted by COUNTA(). While Excel evaluates the expression above to 0 (if all cells are empty), PhpSpreadsheet (4.5.0) returns 4.

I did not check, but COUNT will most likely suffer from the same problem.

test.xlsx