pike.c: handle 0 case in repetition

test.sh

@@ -1,6 +1,20 @@
 #!/bin/sh
 
 regex="\
+a{0}
+(aaaa){0,}
+(aaaa){0,0}
+(aaa+a){0,}
+(aaaa){0,0}|a
+(aaaa){0,0}|abc
+(aaaa){0,}|bc
+(aaaa){0,2}|bc
+(aaaa){0,2}|bc
+(aaaa){0,2}|bc
+bc{0}|(aaaa){0,2}
+(bc{0,})+|(aaaa){0,2}
+(bc{0,}){3,5}|(aaaa){0,2}
+(bc{0,}){3,5}|(aaaa){0,2}
 abc
 cde
 abc*
@@ -195,6 +209,20 @@ aaaaa(aa)aa(aa(a)a)?aa
 (((?:(?:(?:ffffff(a)?ffff)+)+?)*)*)+
 "
 input="\
+aaaaaaaaaa
+aaaaaaaaaa
+aaaaaaaaaa
+aaaaaaaaaa
+aaaaaaaaaa
+aaaaaaaaaa
+aaaaaaaaaa
+aaaaaa
+aaaa
+aaa
+ccc
+bbbbccc
+bbbbbccccc
+bbbbbbccccc
 abcdef
 abcdef
 abdef
@@ -389,6 +417,20 @@ fffffaffffffffff
 fffffffffffffffffffffffff
 "
 expect="\
+(0,0)
+(0,8)(4,8)
+(0,0)(?,?)
+(0,10)(0,10)
+(0,0)(?,?)
+(0,0)(?,?)
+(0,8)(4,8)
+(0,4)(0,4)
+(0,4)(0,4)
+(0,0)(?,?)
+(0,0)(?,?)
+(0,7)(3,7)(?,?)
+(0,10)(4,10)(?,?)
+(0,5)(4,5)(?,?)
 (0,3)
 (2,5)
 (0,2)