Please describe the problem:
When trying printing a number that happened to be integer (number == ((int)
number)), xmlXPathFormatNumber does a bunch of divide/modulo arithmetic to
generate the characters (instead of deferring to printf like it does for numbers
with a floating-point portion).

This code has an overflow for the case of -2147483648 (0x80000000), since that
number has the strange property that -x == x (for machines where sizeof(int) ==
4). This means that the code doing 
if(val  < 0) val = -val;
in an attempt to get an absolute value fails, and val is still negative.
Therefor, val % 10 can be negative (on x86, at least, it is). So when it adds
'0' + val % 10 to get digits, the results are... interesting :-)


Steps to reproduce:
1. ./testXPath 'string(-2147483648.0)'


Actual results:
Object is a string : -./,),(-*,(

Expected results:
Object is a string : -2147483648

Does this happen every time?
yes

Other information: