quirky inconsistency in stripping whitespace from function args?

[Robert P. J. Day]

  in testing the treatment of whitespace in function calls in make
3.80, i've noticed that, in user-defined functions, all whitespace
(that is, both leading and trailing) appears to be preserved on all of
the arguments.  thus, if i define a function and call it with

  $(call myfunc,  fred ,  barney)
                ^^    ^ ^^

the args that are passed are, respectively

  "  fred "
  "  barney"

  but from page 64 of the 3rd edition of the o'reilly make book, when
discussing *built-in* functions, i read:

  "Leading whitespace is trimmed from the first argument, but all
subsequent arguments include any leading (and, of course, embedded and
following) whitespace."

  so the only difference in behaviour between user-defined and
built-in functions is the treatment of the leading whitespace of the
first argument?  isn't this kind of a subtle inconsistency that might
trap the unwary?  or am i reading this incorrectly?

rday