diff -r c040f992052f -r 1c52a0eeb952 vendor/github.com/russross/blackfriday/smartypants.go
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/github.com/russross/blackfriday/smartypants.go	Sun Feb 16 18:54:01 2020 +0100
@@ -0,0 +1,430 @@
+//
+// Blackfriday Markdown Processor
+// Available at http://github.com/russross/blackfriday
+//
+// Copyright © 2011 Russ Ross <russ@russross.com>.
+// Distributed under the Simplified BSD License.
+// See README.md for details.
+//
+
+//
+//
+// SmartyPants rendering
+//
+//
+
+package blackfriday
+
+import (
+	"bytes"
+)
+
+type smartypantsData struct {
+	inSingleQuote bool
+	inDoubleQuote bool
+}
+
+func wordBoundary(c byte) bool {
+	return c == 0 || isspace(c) || ispunct(c)
+}
+
+func tolower(c byte) byte {
+	if c >= 'A' && c <= 'Z' {
+		return c - 'A' + 'a'
+	}
+	return c
+}
+
+func isdigit(c byte) bool {
+	return c >= '0' && c <= '9'
+}
+
+func smartQuoteHelper(out *bytes.Buffer, previousChar byte, nextChar byte, quote byte, isOpen *bool, addNBSP bool) bool {
+	// edge of the buffer is likely to be a tag that we don't get to see,
+	// so we treat it like text sometimes
+
+	// enumerate all sixteen possibilities for (previousChar, nextChar)
+	// each can be one of {0, space, punct, other}
+	switch {
+	case previousChar == 0 && nextChar == 0:
+		// context is not any help here, so toggle
+		*isOpen = !*isOpen
+	case isspace(previousChar) && nextChar == 0:
+		// [ "] might be [ "<code>foo...]
+		*isOpen = true
+	case ispunct(previousChar) && nextChar == 0:
+		// [!"] hmm... could be [Run!"] or [("<code>...]
+		*isOpen = false
+	case /* isnormal(previousChar) && */ nextChar == 0:
+		// [a"] is probably a close
+		*isOpen = false
+	case previousChar == 0 && isspace(nextChar):
+		// [" ] might be [...foo</code>" ]
+		*isOpen = false
+	case isspace(previousChar) && isspace(nextChar):
+		// [ " ] context is not any help here, so toggle
+		*isOpen = !*isOpen
+	case ispunct(previousChar) && isspace(nextChar):
+		// [!" ] is probably a close
+		*isOpen = false
+	case /* isnormal(previousChar) && */ isspace(nextChar):
+		// [a" ] this is one of the easy cases
+		*isOpen = false
+	case previousChar == 0 && ispunct(nextChar):
+		// ["!] hmm... could be ["$1.95] or [</code>"!...]
+		*isOpen = false
+	case isspace(previousChar) && ispunct(nextChar):
+		// [ "!] looks more like [ "$1.95]
+		*isOpen = true
+	case ispunct(previousChar) && ispunct(nextChar):
+		// [!"!] context is not any help here, so toggle
+		*isOpen = !*isOpen
+	case /* isnormal(previousChar) && */ ispunct(nextChar):
+		// [a"!] is probably a close
+		*isOpen = false
+	case previousChar == 0 /* && isnormal(nextChar) */ :
+		// ["a] is probably an open
+		*isOpen = true
+	case isspace(previousChar) /* && isnormal(nextChar) */ :
+		// [ "a] this is one of the easy cases
+		*isOpen = true
+	case ispunct(previousChar) /* && isnormal(nextChar) */ :
+		// [!"a] is probably an open
+		*isOpen = true
+	default:
+		// [a'b] maybe a contraction?
+		*isOpen = false
+	}
+
+	// Note that with the limited lookahead, this non-breaking
+	// space will also be appended to single double quotes.
+	if addNBSP && !*isOpen {
+		out.WriteString("&nbsp;")
+	}
+
+	out.WriteByte('&')
+	if *isOpen {
+		out.WriteByte('l')
+	} else {
+		out.WriteByte('r')
+	}
+	out.WriteByte(quote)
+	out.WriteString("quo;")
+
+	if addNBSP && *isOpen {
+		out.WriteString("&nbsp;")
+	}
+
+	return true
+}
+
+func smartSingleQuote(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+	if len(text) >= 2 {
+		t1 := tolower(text[1])
+
+		if t1 == '\'' {
+			nextChar := byte(0)
+			if len(text) >= 3 {
+				nextChar = text[2]
+			}
+			if smartQuoteHelper(out, previousChar, nextChar, 'd', &smrt.inDoubleQuote, false) {
+				return 1
+			}
+		}
+
+		if (t1 == 's' || t1 == 't' || t1 == 'm' || t1 == 'd') && (len(text) < 3 || wordBoundary(text[2])) {
+			out.WriteString("&rsquo;")
+			return 0
+		}
+
+		if len(text) >= 3 {
+			t2 := tolower(text[2])
+
+			if ((t1 == 'r' && t2 == 'e') || (t1 == 'l' && t2 == 'l') || (t1 == 'v' && t2 == 'e')) &&
+				(len(text) < 4 || wordBoundary(text[3])) {
+				out.WriteString("&rsquo;")
+				return 0
+			}
+		}
+	}
+
+	nextChar := byte(0)
+	if len(text) > 1 {
+		nextChar = text[1]
+	}
+	if smartQuoteHelper(out, previousChar, nextChar, 's', &smrt.inSingleQuote, false) {
+		return 0
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func smartParens(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+	if len(text) >= 3 {
+		t1 := tolower(text[1])
+		t2 := tolower(text[2])
+
+		if t1 == 'c' && t2 == ')' {
+			out.WriteString("&copy;")
+			return 2
+		}
+
+		if t1 == 'r' && t2 == ')' {
+			out.WriteString("&reg;")
+			return 2
+		}
+
+		if len(text) >= 4 && t1 == 't' && t2 == 'm' && text[3] == ')' {
+			out.WriteString("&trade;")
+			return 3
+		}
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func smartDash(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+	if len(text) >= 2 {
+		if text[1] == '-' {
+			out.WriteString("&mdash;")
+			return 1
+		}
+
+		if wordBoundary(previousChar) && wordBoundary(text[1]) {
+			out.WriteString("&ndash;")
+			return 0
+		}
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func smartDashLatex(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+	if len(text) >= 3 && text[1] == '-' && text[2] == '-' {
+		out.WriteString("&mdash;")
+		return 2
+	}
+	if len(text) >= 2 && text[1] == '-' {
+		out.WriteString("&ndash;")
+		return 1
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func smartAmpVariant(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte, quote byte, addNBSP bool) int {
+	if bytes.HasPrefix(text, []byte("&quot;")) {
+		nextChar := byte(0)
+		if len(text) >= 7 {
+			nextChar = text[6]
+		}
+		if smartQuoteHelper(out, previousChar, nextChar, quote, &smrt.inDoubleQuote, addNBSP) {
+			return 5
+		}
+	}
+
+	if bytes.HasPrefix(text, []byte("&#0;")) {
+		return 3
+	}
+
+	out.WriteByte('&')
+	return 0
+}
+
+func smartAmp(angledQuotes, addNBSP bool) func(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+	var quote byte = 'd'
+	if angledQuotes {
+		quote = 'a'
+	}
+
+	return func(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+		return smartAmpVariant(out, smrt, previousChar, text, quote, addNBSP)
+	}
+}
+
+func smartPeriod(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+	if len(text) >= 3 && text[1] == '.' && text[2] == '.' {
+		out.WriteString("&hellip;")
+		return 2
+	}
+
+	if len(text) >= 5 && text[1] == ' ' && text[2] == '.' && text[3] == ' ' && text[4] == '.' {
+		out.WriteString("&hellip;")
+		return 4
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func smartBacktick(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+	if len(text) >= 2 && text[1] == '`' {
+		nextChar := byte(0)
+		if len(text) >= 3 {
+			nextChar = text[2]
+		}
+		if smartQuoteHelper(out, previousChar, nextChar, 'd', &smrt.inDoubleQuote, false) {
+			return 1
+		}
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func smartNumberGeneric(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+	if wordBoundary(previousChar) && previousChar != '/' && len(text) >= 3 {
+		// is it of the form digits/digits(word boundary)?, i.e., \d+/\d+\b
+		// note: check for regular slash (/) or fraction slash (⁄, 0x2044, or 0xe2 81 84 in utf-8)
+		//       and avoid changing dates like 1/23/2005 into fractions.
+		numEnd := 0
+		for len(text) > numEnd && isdigit(text[numEnd]) {
+			numEnd++
+		}
+		if numEnd == 0 {
+			out.WriteByte(text[0])
+			return 0
+		}
+		denStart := numEnd + 1
+		if len(text) > numEnd+3 && text[numEnd] == 0xe2 && text[numEnd+1] == 0x81 && text[numEnd+2] == 0x84 {
+			denStart = numEnd + 3
+		} else if len(text) < numEnd+2 || text[numEnd] != '/' {
+			out.WriteByte(text[0])
+			return 0
+		}
+		denEnd := denStart
+		for len(text) > denEnd && isdigit(text[denEnd]) {
+			denEnd++
+		}
+		if denEnd == denStart {
+			out.WriteByte(text[0])
+			return 0
+		}
+		if len(text) == denEnd || wordBoundary(text[denEnd]) && text[denEnd] != '/' {
+			out.WriteString("<sup>")
+			out.Write(text[:numEnd])
+			out.WriteString("</sup>&frasl;<sub>")
+			out.Write(text[denStart:denEnd])
+			out.WriteString("</sub>")
+			return denEnd - 1
+		}
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func smartNumber(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+	if wordBoundary(previousChar) && previousChar != '/' && len(text) >= 3 {
+		if text[0] == '1' && text[1] == '/' && text[2] == '2' {
+			if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' {
+				out.WriteString("&frac12;")
+				return 2
+			}
+		}
+
+		if text[0] == '1' && text[1] == '/' && text[2] == '4' {
+			if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' || (len(text) >= 5 && tolower(text[3]) == 't' && tolower(text[4]) == 'h') {
+				out.WriteString("&frac14;")
+				return 2
+			}
+		}
+
+		if text[0] == '3' && text[1] == '/' && text[2] == '4' {
+			if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' || (len(text) >= 6 && tolower(text[3]) == 't' && tolower(text[4]) == 'h' && tolower(text[5]) == 's') {
+				out.WriteString("&frac34;")
+				return 2
+			}
+		}
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func smartDoubleQuoteVariant(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte, quote byte) int {
+	nextChar := byte(0)
+	if len(text) > 1 {
+		nextChar = text[1]
+	}
+	if !smartQuoteHelper(out, previousChar, nextChar, quote, &smrt.inDoubleQuote, false) {
+		out.WriteString("&quot;")
+	}
+
+	return 0
+}
+
+func smartDoubleQuote(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+	return smartDoubleQuoteVariant(out, smrt, previousChar, text, 'd')
+}
+
+func smartAngledDoubleQuote(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+	return smartDoubleQuoteVariant(out, smrt, previousChar, text, 'a')
+}
+
+func smartLeftAngle(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int {
+	i := 0
+
+	for i < len(text) && text[i] != '>' {
+		i++
+	}
+
+	out.Write(text[:i+1])
+	return i
+}
+
+type smartCallback func(out *bytes.Buffer, smrt *smartypantsData, previousChar byte, text []byte) int
+
+type smartypantsRenderer [256]smartCallback
+
+var (
+	smartAmpAngled      = smartAmp(true, false)
+	smartAmpAngledNBSP  = smartAmp(true, true)
+	smartAmpRegular     = smartAmp(false, false)
+	smartAmpRegularNBSP = smartAmp(false, true)
+)
+
+func smartypants(flags int) *smartypantsRenderer {
+	r := new(smartypantsRenderer)
+	addNBSP := flags&HTML_SMARTYPANTS_QUOTES_NBSP != 0
+	if flags&HTML_SMARTYPANTS_ANGLED_QUOTES == 0 {
+		r['"'] = smartDoubleQuote
+		if !addNBSP {
+			r['&'] = smartAmpRegular
+		} else {
+			r['&'] = smartAmpRegularNBSP
+		}
+	} else {
+		r['"'] = smartAngledDoubleQuote
+		if !addNBSP {
+			r['&'] = smartAmpAngled
+		} else {
+			r['&'] = smartAmpAngledNBSP
+		}
+	}
+	r['\''] = smartSingleQuote
+	r['('] = smartParens
+	if flags&HTML_SMARTYPANTS_DASHES != 0 {
+		if flags&HTML_SMARTYPANTS_LATEX_DASHES == 0 {
+			r['-'] = smartDash
+		} else {
+			r['-'] = smartDashLatex
+		}
+	}
+	r['.'] = smartPeriod
+	if flags&HTML_SMARTYPANTS_FRACTIONS == 0 {
+		r['1'] = smartNumber
+		r['3'] = smartNumber
+	} else {
+		for ch := '1'; ch <= '9'; ch++ {
+			r[ch] = smartNumberGeneric
+		}
+	}
+	r['<'] = smartLeftAngle
+	r['`'] = smartBacktick
+	return r
+}