column 1 = gawk
column 2 = mawk
column 3 = original-awk


PARAMETER: (that is: the string was passed as a $'...' string to the function, which in turned was printf '%s' piped into *awk.)
**********
'':           0  0  0
\n:           1  1  1
\n\n:         2  2  2
\n\n\n:       3  3  3
\n\x00\n\n:   1  1  1
a:            0  0  0
a\n:          1  0  0
a\n\n:        2  1  1
\na\n\n:      2  1  1
a\n\nb\n:     1  0  0
a\n\n\x00\n:  2  1  1


STDIN:  (that is: the string was directly printf '%s' piped to the function which it it was read from *awk.)
******
'':           0  0  0
\n:           1  1  1
\n\n:         2  2  2
\n\n\n:       3  3  3
\n\x00\n\n:   2  1  3
a:            0  0  0
a\n:          1  0  0
a\n\n:        2  1  1
\na\n\n:      2  1  1
a\n\nb\n:     1  0  0
a\n\n\x00\n:  1  0  2