Plauger & Brodie strtod description

[Richard A. O'Keefe]

The railroad diagram on page 163 of "Standard C" by Plauger & Brodie
suggests that the string argument of strtod() must contain either a
decimal point or an exponent, so that strtod("1234", (char**)NULL)
must return 0.0 if called in the "C" locale.  This requirement matches
the syntax of floating-point constants in C, but it is more restrictive
than current versions of strtod(), which accept "1234".

Q1: have Plauger & Brodie got it right?
Q2: if they have got it right, why does the standard prohibit "1234"
    in *data*?