[NTG-context] \placeformula and $$ doesn't work anymore

[Aditya Mahajan]

On Mon, 4 Dec 2006, Hubertus Schmidt wrote:

> Hi all,
> for some weeks I need to tex formulas again and tried the way I used to do it:
> 
> \placeformula
> $$
> f(t)={1\over2\pi}\int_0^\infty e^{i(\omega t-kx)} dx
> $$
> 
> It didn't work anymore?!? It doesn't place a number nor does it do the spacing
> properly. It does work the "context" way using
> 
> \placeformula
> \startformula
> f(t)={1\over2\pi}\int_0^\infty e^{i(\omega t-kx)} dx
> \stopformula

This is a bug in doplaceformula. I do not know how to avoid it, but 
the next code illustrates what is happening.

\def\dotest{
   \def\nextnext{$}%
   \ifx\next\nextnext
     Inside dispplaceformula\ldots % This always fails
   \else
     Inside dodoplaceformula\ldots
  \fi}

\def\test{\futurelet\next\dotest}

\test$$A = B$$

This prints "Inside dodoplaceformula" even though the next character 
is \$.

So, the \next=\nextnext branch never matches. I do not know why this 
happens, but a more robust check is needed in doplaceformula.

Aditya