Add support for markdown to HTML conversion (matrix). Closes #663 (#670)

This uses our own gomatrix lib with the SendHTML function which
adds HTML to formatted_body in matrix.
golang-commonmark is used to convert markdown into valid HTML.

1 files changed, 287 insertions, 0 deletions

diff --git a/vendor/gitlab.com/golang-commonmark/puny/puny.go b/vendor/gitlab.com/golang-commonmark/puny/puny.go
new file mode 100644
index 00000000..8f71402c
--- /dev/null
+++ b/vendor/gitlab.com/golang-commonmark/puny/puny.go
@@ -0,0 +1,287 @@
+// Copyright 2015 The 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 puny provides functions for encoding/decoding to/from punycode.
+package puny
+
+import (
+	"errors"
+	"strings"
+	"unicode/utf8"
+)
+
+const (
+	maxInt32      int32 = 2147483647
+	base          int32 = 36
+	tMin          int32 = 1
+	baseMinusTMin       = base - tMin
+	tMax          int32 = 26
+	skew          int32 = 38
+	damp          int32 = 700
+	initialBias   int32 = 72
+	initialN      int32 = 128
+)
+
+var (
+	ErrOverflow     = errors.New("overflow: input needs wider integers to process")
+	ErrNotBasic     = errors.New("illegal input >= 0x80 (not a basic code point)")
+	ErrInvalidInput = errors.New("invalid input")
+)
+
+func adapt(delta, numPoints int32, firstTime bool) int32 {
+	if firstTime {
+		delta /= damp
+	} else {
+		delta /= 2
+	}
+	delta += delta / numPoints
+	k := int32(0)
+	for delta > baseMinusTMin*tMax/2 {
+		delta = delta / baseMinusTMin
+		k += base
+	}
+	return k + (baseMinusTMin+1)*delta/(delta+skew)
+}
+
+func basicToDigit(b byte) int32 {
+	switch {
+	case b >= '0' && b <= '9':
+		return int32(b - 22)
+	case b >= 'A' && b <= 'Z':
+		return int32(b - 'A')
+	case b >= 'a' && b <= 'z':
+		return int32(b - 'a')
+	}
+	return base
+}
+
+func digitToBasic(digit int32) byte {
+	switch {
+	case digit >= 0 && digit <= 25:
+		return byte(digit) + 'a'
+	case digit >= 26 && digit <= 35:
+		return byte(digit) - 26 + '0'
+	}
+	panic("unreachable")
+}
+
+func lastIndex(s string, c byte) int {
+	for i := len(s) - 1; i >= 0; i-- {
+		if s[i] == c {
+			return i
+		}
+	}
+	return -1
+}
+
+func ascii(s string) bool {
+	for _, r := range s {
+		if r > 0x7e {
+			return false
+		}
+	}
+	return true
+}
+
+// Decode converts a Punycode string of ASCII-only symbols to a string of Unicode symbols.
+func Decode(s string) (string, error) {
+	basic := lastIndex(s, '-')
+	output := make([]rune, 0, len(s))
+	for i := 0; i < basic; i++ {
+		b := s[i]
+		if b >= 0x80 {
+			return "", ErrNotBasic
+		}
+		output = append(output, rune(b))
+	}
+
+	i, n, bias, pos := int32(0), initialN, initialBias, basic+1
+
+	for pos < len(s) {
+		oldi, w, k := i, int32(1), base
+		for {
+			digit := basicToDigit(s[pos])
+			pos++
+
+			if digit >= base || digit > (maxInt32-i)/w {
+				return "", ErrOverflow
+			}
+
+			i += digit * w
+
+			t := k - bias
+			if t < tMin {
+				t = tMin
+			} else if t > tMax {
+				t = tMax
+			}
+
+			if digit < t {
+				break
+			}
+
+			if pos == len(s) {
+				return "", ErrInvalidInput
+			}
+
+			baseMinusT := base - t
+			if w > maxInt32/baseMinusT {
+				return "", ErrOverflow
+			}
+
+			w *= baseMinusT
+			k += base
+		}
+
+		out := int32(len(output) + 1)
+		bias = adapt(i-oldi, out, oldi == 0)
+
+		if i/out > maxInt32-n {
+			return "", ErrOverflow
+		}
+
+		n += i / out
+		i %= out
+
+		output = append(output, 0)
+		copy(output[i+1:], output[i:])
+		output[i] = rune(n)
+
+		i++
+	}
+
+	return string(output), nil
+}
+
+// Encode converts a string of Unicode symbols (e.g. a domain name label) to a
+// Punycode string of ASCII-only symbols.
+func Encode(input string) (string, error) {
+	n := initialN
+	delta := int32(0)
+	bias := initialBias
+
+	var output []byte
+	runes := 0
+	for _, r := range input {
+		if r >= 0x80 {
+			runes++
+			continue
+		}
+		output = append(output, byte(r))
+	}
+
+	basicLength := len(output)
+	handledCPCount := basicLength
+
+	if basicLength > 0 {
+		output = append(output, '-')
+	}
+
+	for runes > 0 {
+		m := maxInt32
+		for _, r := range input {
+			if r >= n && r < m {
+				m = r
+			}
+		}
+
+		handledCPCountPlusOne := int32(handledCPCount + 1)
+		if m-n > (maxInt32-delta)/handledCPCountPlusOne {
+			return "", ErrOverflow
+		}
+
+		delta += (m - n) * handledCPCountPlusOne
+		n = m
+
+		for _, r := range input {
+			if r < n {
+				delta++
+				if delta < 0 {
+					return "", ErrOverflow
+				}
+				continue
+			}
+			if r > n {
+				continue
+			}
+			q := delta
+			for k := base; ; k += base {
+				t := k - bias
+				if t < tMin {
+					t = tMin
+				} else if t > tMax {
+					t = tMax
+				}
+				if q < t {
+					break
+				}
+				qMinusT := q - t
+				baseMinusT := base - t
+				output = append(output, digitToBasic(t+qMinusT%baseMinusT))
+				q = qMinusT / baseMinusT
+			}
+
+			output = append(output, digitToBasic(q))
+			bias = adapt(delta, handledCPCountPlusOne, handledCPCount == basicLength)
+			delta = 0
+			handledCPCount++
+			runes--
+		}
+		delta++
+		n++
+	}
+	return string(output), nil
+}
+
+func sep(r rune) bool { return r == '.' || r == '。' || r == '．' || r == '｡' }
+
+func mapLabels(s string, fn func(string) string) string {
+	var result string
+	i := strings.IndexByte(s, '@')
+	if i != -1 {
+		result = s[:i+1]
+		s = s[i+1:]
+	}
+	var labels []string
+	start := 0
+	for i, r := range s {
+		if !sep(r) {
+			continue
+		}
+		labels = append(labels, fn(s[start:i]))
+		start = i + utf8.RuneLen(r)
+	}
+	labels = append(labels, fn(s[start:]))
+	return result + strings.Join(labels, ".")
+}
+
+// ToUnicode converts a Punycode string representing a domain name or an email address
+// to Unicode. Only the Punycoded parts of the input will be converted.
+func ToUnicode(s string) string {
+	return mapLabels(s, func(s string) string {
+		if !strings.HasPrefix(s, "xn--") {
+			return s
+		}
+		d, err := Decode(strings.ToLower(s[4:]))
+		if err != nil {
+			return s
+		}
+		return d
+	})
+}
+
+// ToASCII converts a Unicode string representing a domain name or an email address to
+// Punycode. Only the non-ASCII parts of the domain name will be converted.
+func ToASCII(s string) string {
+	return mapLabels(s, func(s string) string {
+		if ascii(s) {
+			return s
+		}
+		d, err := Encode(s)
+		if err != nil {
+			return s
+		}
+		return "xn--" + d
+	})
+}