1 files changed, 70 insertions, 0 deletions
diff --git a/vendor/golang.org/x/text/secure/precis/nickname.go b/vendor/golang.org/x/text/secure/precis/nickname.go
new file mode 100644
index 000000000..cd54b9e69
--- /dev/null
+++ b/vendor/golang.org/x/text/secure/precis/nickname.go
@@ -0,0 +1,70 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package precis
+
+import (
+	"unicode"
+	"unicode/utf8"
+
+	"golang.org/x/text/transform"
+)
+
+type nickAdditionalMapping struct {
+	// TODO: This transformer needs to be stateless somehow…
+	notStart  bool
+	prevSpace bool
+}
+
+func (t *nickAdditionalMapping) Reset() {
+	t.prevSpace = false
+	t.notStart = false
+}
+
+func (t *nickAdditionalMapping) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	// RFC 7700 §2.1.  Rules
+	//
+	// 2.  Additional Mapping Rule: The additional mapping rule consists of
+	//                              the following sub-rules.
+	//
+	//        1.  Any instances of non-ASCII space MUST be mapped to ASCII
+	//            space (U+0020); a non-ASCII space is any Unicode code point
+	//            having a general category of "Zs", naturally with the
+	//            exception of U+0020.
+	//
+	//        2.  Any instances of the ASCII space character at the beginning
+	//            or end of a nickname MUST be removed (e.g., "stpeter " is
+	//            mapped to "stpeter").
+	//
+	//        3.  Interior sequences of more than one ASCII space character
+	//            MUST be mapped to a single ASCII space character (e.g.,
+	//            "St  Peter" is mapped to "St Peter").
+
+	for nSrc < len(src) {
+		r, size := utf8.DecodeRune(src[nSrc:])
+		if size == 0 { // Incomplete UTF-8 encoding
+			if !atEOF {
+				return nDst, nSrc, transform.ErrShortSrc
+			}
+			size = 1
+		}
+		if unicode.Is(unicode.Zs, r) {
+			t.prevSpace = true
+		} else {
+			if t.prevSpace && t.notStart {
+				dst[nDst] = ' '
+				nDst += 1
+			}
+			if size != copy(dst[nDst:], src[nSrc:nSrc+size]) {
+				nDst += size
+				return nDst, nSrc, transform.ErrShortDst
+			}
+			nDst += size
+			t.prevSpace = false
+			t.notStart = true
+		}
+		nSrc += size
+	}
+	return nDst, nSrc, nil
+}