fix pathological cases

test.sh

@@ -106,6 +106,14 @@ qwerty.*$
 (aaaa|aaa|a){3,4}
 (a)(a)
 (a){2}
+(a|bcdef|g|ab|c|d|e|efg|fg)*
+(.*) (.*) (.*) (.*) (.*)
+(.+?)(.+?)
+(a?)(a?)(a?)aaa
+(ab)?(ab)?(ab)?aaa
+(.+)(.+)
+a(?:b|c|d){4,5}(.)
+(?:c|d)(?:)(?:a(?:)(?:b)(?:b(?:))(?:b(?:)(?:b)))
 "
 input="\
 abcdef
@@ -213,6 +221,14 @@ aaaaaa
 aaaaaaaaaa
 aaaa
 aaaa
+abcdefg
+a  c d ee fff
+abcd
+aaa
+abaaa
+abcd
+acdbcdbe
+cabbbb
 "
 expect="\
 (0,3)
@@ -320,6 +336,14 @@ expect="\
 (0,10)(9,10)
 (0,2)(0,1)(1,2)
 (0,2)(1,2)
+(0,7)(6,7)
+(0,13)(0,2)(3,4)(5,6)(7,9)(10,13)
+(0,2)(0,1)(1,2)
+(0,3)(0,0)(0,0)(0,0)
+(0,5)(0,2)(?,?)(?,?)
+(0,4)(0,3)(3,4)
+(0,7)(6,7)
+(0,6)
 (0,0)
 "