[dev-context] \sqrt in expansions bug

[Hans Hagen]

Taco Hoekwater wrote:

> Hi,
>
> Macros that use \doifnextcharelse should all be defined
> as \unexpanded, to prevent errors like:
>
>   \expanded{$\sqrt 2$}
>
> Also affected are:
>
>   \decrement
>   \increment
>
> maybe there are others, but these were easy to spot because
> they were single-line \def's. The \sqrt is painful, because it
> is likely to appear in \write-s


i ran into that yesterday  and made it unexpanded; this problem was 
introduced when (on user request) sqrt got the optional arg and thereby 
was no longer defined as math thingie with automatic protection.

Hans