remove dependency on less function

inline.go

@@ -634,7 +634,7 @@ func isSafeLink(link []byte) bool {
 	for _, prefix := range validUris {
 		// TODO: handle unicode here
 		// case-insensitive prefix test
-		if len(link) > len(prefix) && !less(link[:len(prefix)], prefix) && !less(prefix, link[:len(prefix)]) && isalnum(link[len(prefix)]) {
+		if len(link) > len(prefix) && bytes.Equal(bytes.ToLower(link[:len(prefix)]), prefix) && isalnum(link[len(prefix)]) {
 			return true
 		}
 	}

markdown.go

@@ -14,7 +14,6 @@ package blackfriday
 
 import (
 	"bytes"
-	"unicode"
 )
 
 // These are the supported markdown parsing extensions.
@@ -275,33 +274,6 @@ type reference struct {
 	title []byte
 }
 
-// Compare two []byte values (case-insensitive), returning
-// true if a is less than b.
-func less(a []byte, b []byte) bool {
-	// adapted from bytes.Compare in stdlib
-	m := len(a)
-	if m > len(b) {
-		m = len(b)
-	}
-	for i, ac := range a[0:m] {
-		// do a case-insensitive comparison
-		ai, bi := unicode.ToLower(int(ac)), unicode.ToLower(int(b[i]))
-		switch {
-		case ai > bi:
-			return false
-		case ai < bi:
-			return true
-		}
-	}
-	switch {
-	case len(a) < len(b):
-		return true
-	case len(a) > len(b):
-		return false
-	}
-	return false
-}
-
 // Check whether or not data starts with a reference link.
 // If so, it is parsed and stored in the list of references
 // (in the render struct).