Add Mumble support (#1245)

vendor/github.com/vincent-petithory/dataurl/rfc2396.go

@@ -0,0 +1,130 @@
+package dataurl
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+)
+
+// Escape implements URL escaping, as defined in RFC 2397 (http://tools.ietf.org/html/rfc2397).
+// It differs a bit from net/url's QueryEscape and QueryUnescape, e.g how spaces are treated (+ instead of %20):
+//
+// Only ASCII chars are allowed. Reserved chars are escaped to their %xx form.
+// Unreserved chars are [a-z], [A-Z], [0-9], and -_.!~*\().
+func Escape(data []byte) string {
+	var buf = new(bytes.Buffer)
+	for _, b := range data {
+		switch {
+		case isUnreserved(b):
+			buf.WriteByte(b)
+		default:
+			fmt.Fprintf(buf, "%%%02X", b)
+		}
+	}
+	return buf.String()
+}
+
+// EscapeString is like Escape, but taking
+// a string as argument.
+func EscapeString(s string) string {
+	return Escape([]byte(s))
+}
+
+// isUnreserved return true
+// if the byte c is an unreserved char,
+// as defined in RFC 2396.
+func isUnreserved(c byte) bool {
+	return (c >= 'a' && c <= 'z') ||
+		(c >= 'A' && c <= 'Z') ||
+		(c >= '0' && c <= '9') ||
+		c == '-' ||
+		c == '_' ||
+		c == '.' ||
+		c == '!' ||
+		c == '~' ||
+		c == '*' ||
+		c == '\'' ||
+		c == '(' ||
+		c == ')'
+}
+
+func isHex(c byte) bool {
+	switch {
+	case c >= 'a' && c <= 'f':
+		return true
+	case c >= 'A' && c <= 'F':
+		return true
+	case c >= '0' && c <= '9':
+		return true
+	}
+	return false
+}
+
+// borrowed from net/url/url.go
+func unhex(c byte) byte {
+	switch {
+	case '0' <= c && c <= '9':
+		return c - '0'
+	case 'a' <= c && c <= 'f':
+		return c - 'a' + 10
+	case 'A' <= c && c <= 'F':
+		return c - 'A' + 10
+	}
+	return 0
+}
+
+// Unescape unescapes a character sequence
+// escaped with Escape(String?).
+func Unescape(s string) ([]byte, error) {
+	var buf = new(bytes.Buffer)
+	reader := strings.NewReader(s)
+
+	for {
+		r, size, err := reader.ReadRune()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, err
+		}
+		if size > 1 {
+			return nil, fmt.Errorf("rfc2396: non-ASCII char detected")
+		}
+
+		switch r {
+		case '%':
+			eb1, err := reader.ReadByte()
+			if err == io.EOF {
+				return nil, fmt.Errorf("rfc2396: unexpected end of unescape sequence")
+			}
+			if err != nil {
+				return nil, err
+			}
+			if !isHex(eb1) {
+				return nil, fmt.Errorf("rfc2396: invalid char 0x%x in unescape sequence", r)
+			}
+			eb0, err := reader.ReadByte()
+			if err == io.EOF {
+				return nil, fmt.Errorf("rfc2396: unexpected end of unescape sequence")
+			}
+			if err != nil {
+				return nil, err
+			}
+			if !isHex(eb0) {
+				return nil, fmt.Errorf("rfc2396: invalid char 0x%x in unescape sequence", r)
+			}
+			buf.WriteByte(unhex(eb0) + unhex(eb1)*16)
+		default:
+			buf.WriteByte(byte(r))
+		}
+	}
+	return buf.Bytes(), nil
+}
+
+// UnescapeToString is like Unescape, but returning
+// a string.
+func UnescapeToString(s string) (string, error) {
+	b, err := Unescape(s)
+	return string(b), err
+}