diff --git a/vendor/golang.org/x/net/idna/trie.go b/vendor/golang.org/x/net/idna/trie.go
new file mode 100644
index 0000000..c4ef847
--- /dev/null
+++ b/vendor/golang.org/x/net/idna/trie.go
@@ -0,0 +1,72 @@
+// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
+
+// Copyright 2016 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 idna
+
+// appendMapping appends the mapping for the respective rune. isMapped must be
+// true. A mapping is a categorization of a rune as defined in UTS #46.
+func (c info) appendMapping(b []byte, s string) []byte {
+	index := int(c >> indexShift)
+	if c&xorBit == 0 {
+		s := mappings[index:]
+		return append(b, s[1:s[0]+1]...)
+	}
+	b = append(b, s...)
+	if c&inlineXOR == inlineXOR {
+		// TODO: support and handle two-byte inline masks
+		b[len(b)-1] ^= byte(index)
+	} else {
+		for p := len(b) - int(xorData[index]); p < len(b); p++ {
+			index++
+			b[p] ^= xorData[index]
+		}
+	}
+	return b
+}
+
+// Sparse block handling code.
+
+type valueRange struct {
+	value  uint16 // header: value:stride
+	lo, hi byte   // header: lo:n
+}
+
+type sparseBlocks struct {
+	values []valueRange
+	offset []uint16
+}
+
+var idnaSparse = sparseBlocks{
+	values: idnaSparseValues[:],
+	offset: idnaSparseOffset[:],
+}
+
+// Don't use newIdnaTrie to avoid unconditional linking in of the table.
+var trie = &idnaTrie{}
+
+// lookup determines the type of block n and looks up the value for b.
+// For n < t.cutoff, the block is a simple lookup table. Otherwise, the block
+// is a list of ranges with an accompanying value. Given a matching range r,
+// the value for b is by r.value + (b - r.lo) * stride.
+func (t *sparseBlocks) lookup(n uint32, b byte) uint16 {
+	offset := t.offset[n]
+	header := t.values[offset]
+	lo := offset + 1
+	hi := lo + uint16(header.lo)
+	for lo < hi {
+		m := lo + (hi-lo)/2
+		r := t.values[m]
+		if r.lo <= b && b <= r.hi {
+			return r.value + uint16(b-r.lo)*header.value
+		}
+		if b < r.lo {
+			hi = m
+		} else {
+			lo = m + 1
+		}
+	}
+	return 0
+}