First commit

vendor/github.com/tdewolff/parse/html/util.go

@@ -0,0 +1,129 @@
+package html // import "github.com/tdewolff/parse/html"
+
+import "github.com/tdewolff/parse"
+
+var (
+	singleQuoteEntityBytes = []byte("'")
+	doubleQuoteEntityBytes = []byte(""")
+)
+
+var charTable = [256]bool{
+	// ASCII
+	false, false, false, false, false, false, false, false,
+	false, true, true, true, true, true, false, false, // tab, new line, vertical tab, form feed, carriage return
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+
+	true, false, true, false, false, false, true, true, // space, ", &, '
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, true, true, true, false, // <, =, >
+
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+
+	true, false, false, false, false, false, false, false, // `
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+
+	// non-ASCII
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+	false, false, false, false, false, false, false, false,
+}
+
+// EscapeAttrVal returns the escaped attribute value bytes without quotes.
+func EscapeAttrVal(buf *[]byte, orig, b []byte) []byte {
+	singles := 0
+	doubles := 0
+	unquoted := true
+	entities := false
+	for i, c := range b {
+		if charTable[c] {
+			if c == '&' {
+				entities = true
+				if quote, n := parse.QuoteEntity(b[i:]); n > 0 {
+					if quote == '"' {
+						unquoted = false
+						doubles++
+					} else {
+						unquoted = false
+						singles++
+					}
+				}
+			} else {
+				unquoted = false
+				if c == '"' {
+					doubles++
+				} else if c == '\'' {
+					singles++
+				}
+			}
+		}
+	}
+	if unquoted {
+		return b
+	} else if !entities && len(orig) == len(b)+2 && (singles == 0 && orig[0] == '\'' || doubles == 0 && orig[0] == '"') {
+		return orig
+	}
+
+	n := len(b) + 2
+	var quote byte
+	var escapedQuote []byte
+	if doubles > singles {
+		n += singles * 4
+		quote = '\''
+		escapedQuote = singleQuoteEntityBytes
+	} else {
+		n += doubles * 4
+		quote = '"'
+		escapedQuote = doubleQuoteEntityBytes
+	}
+	if n > cap(*buf) {
+		*buf = make([]byte, 0, n) // maximum size, not actual size
+	}
+	t := (*buf)[:n] // maximum size, not actual size
+	t[0] = quote
+	j := 1
+	start := 0
+	for i, c := range b {
+		if c == '&' {
+			if entityQuote, n := parse.QuoteEntity(b[i:]); n > 0 {
+				j += copy(t[j:], b[start:i])
+				if entityQuote != quote {
+					t[j] = entityQuote
+					j++
+				} else {
+					j += copy(t[j:], escapedQuote)
+				}
+				start = i + n
+			}
+		} else if c == quote {
+			j += copy(t[j:], b[start:i])
+			j += copy(t[j:], escapedQuote)
+			start = i + 1
+		}
+	}
+	j += copy(t[j:], b[start:])
+	t[j] = quote
+	return t[:j+1]
+}