bug#18103: sleep infinity

[積丹尼 Dan Jacobson]

OK however on the sleep info page it says

   Historical implementations of `sleep' have required that NUMBER be
an integer, and only accepted a single argument without a suffix.
However, GNU `sleep' accepts arbitrary floating point numbers.  *Note
Floating point::.

However for at least me, I wouldn't have thought that paragraph also
meant infinity. So you might want to say

   Historical implementations of `sleep' have required that NUMBER be
an integer, and only accepted a single argument without a suffix.
However, GNU `sleep' accepts arbitrary floating point numbers and infinity.  
*Note
Floating point::.