makeinfo bug: macros with no arguments don't work as expected

[Bruno Haible]

Hi,

I'm using makeinfo-4.13, and define a macro that should take no arguments
and should produce an empty expansion. The texinfo doc says:

    If a macro needs no parameters, you can define it either with an empty
  list (address@hidden foo {}') or with no braces at all (address@hidden foo').

When I define the macro as follows:

  @macro texnl{}
  @end macro

and my input text is:

  This is a more low-level API.  The word break property is a property defined
  in Unicode Standard Annex #29, section ``Word Boundaries'', see
  @url{http://www.unicode.org/reports/tr29/address@hidden  It is used
  for determining the word breaks in a string.

then makeinfo produces an info file with this paragraph:

     This is a more low-level API.  The word break property is a property
  defined in Unicode Standard Annex #29, section "Word Boundaries", see
  `http://www.unicode.org/reports/tr29/#Word_Boundaries'.  for
  determining the word breaks in a string.

You can see that the words "It is used" have been omitted. I.e. the macro
is acting like @c.

Whereas when I define the macro as follows:

  @macro texnl
  @end macro

then the output in info format is as expected:

     This is a more low-level API.  The word break property is a property
  defined in Unicode Standard Annex #29, section "Word Boundaries", see
  `http://www.unicode.org/reports/tr29/#Word_Boundaries'.  It is used for
  determining the word breaks in a string.


Bruno