Don't ignore the start offset when searching for an anchored literal.

If we ignore the start offset, then we may report a match where none
exists. This can in particular lead to a match loop that never terminates.

Fixes #255.

src/exec.rs

@@ -589,7 +589,11 @@ impl<'c> ExecNoSync<'c> {
                 lits.find_start(&text[start..])
                     .map(|(s, e)| (start + s, start + e))
             }
-            AnchoredEnd => self.ro.suffixes.find_end(&text),
+            AnchoredEnd => {
+                let lits = &self.ro.suffixes;
+                lits.find_end(&text[start..])
+                    .map(|(s, e)| (start + s, start + e))
+            }
         }
     }
 

tests/misc.rs

@@ -13,6 +13,7 @@ use regex::Regex;
 mat!(prefix_literal_match, r"^abc", r"abc", Some((0, 3)));
 mat!(prefix_literal_nomatch, r"^abc", r"zabc", None);
 mat!(one_literal_edge, r"abc", r"xxxxxab", None);
+matiter!(terminates, r"a$", r"a", (0, 1));
 
 #[test]
 fn eq() {