Patch: 'unsigned < 0' doesn't work (ITS#1705)

[h.b.furuseth@usit.uio.no]

Full_Name: Hallvard B. Furuseth
Version: 2.1.0alpha
OS: Linux
URL: http://folk.uio.no/hbf/OpenLDAP/neg-unsigned.txt
Submission from: (NULL) (158.36.148.34)


This code tested whether an unsigned variable was negative.

In dntest.c, the bug happened if strlen(buf)==0.
In entropy.c, the code didn't catch if the return value from read() was
-1.  -1 is converted to U<TYPE>_MAX when it meets `unsigned <type>'.