match does not work with minus sign

[Paul Romanyszyn]

With Ubuntu 7.10 32 bit I found this problem when parsing git-diff 
output. I compiled the latest stable version and it also had the 
problem. One plus matches one two or three  but one minus only matches 
one minus.
Test program
BEGIN {
   data1 = "+"
   data2 = "++"
   data3 = "+++"
   printf("%d %d 
%d\n",match(data1,data1),match(data1,data2),match(data1,data3))
   data1 = "-"
   data2 = "--"
   data3 = "---"
   printf("%d %d 
%d\n",match(data1,data1),match(data1,data2),match(data1,data3))
}

Output
address@hidden:~/gawksrc$ gawk-3.1.6/gawk -f testmatch.awk
1 1 1
1 0 0

Paul