Add XML option for EscapeAttrVal

html/util.go

@@ -52,7 +52,7 @@ var charTable = [256]bool{
 }
 
 // EscapeAttrVal returns the escaped attribute value bytes without quotes.
-func EscapeAttrVal(buf *[]byte, orig, b []byte) []byte {
+func EscapeAttrVal(buf *[]byte, orig, b []byte, isXML bool) []byte {
 	singles := 0
 	doubles := 0
 	unquoted := true
@@ -80,7 +80,7 @@ func EscapeAttrVal(buf *[]byte, orig, b []byte) []byte {
 			}
 		}
 	}
-	if unquoted {
+	if unquoted && !isXML {
 		return b
 	} else if !entities && len(orig) == len(b)+2 && (singles == 0 && orig[0] == '\'' || doubles == 0 && orig[0] == '"') {
 		return orig
@@ -89,14 +89,14 @@ func EscapeAttrVal(buf *[]byte, orig, b []byte) []byte {
 	n := len(b) + 2
 	var quote byte
 	var escapedQuote []byte
-	if doubles > singles {
-		n += singles * 4
-		quote = '\''
-		escapedQuote = singleQuoteEntityBytes
-	} else {
+	if singles >= doubles || isXML {
 		n += doubles * 4
 		quote = '"'
 		escapedQuote = doubleQuoteEntityBytes
+	} else {
+		n += singles * 4
+		quote = '\''
+		escapedQuote = singleQuoteEntityBytes
 	}
 	if n > cap(*buf) {
 		*buf = make([]byte, 0, n) // maximum size, not actual size

html/util_test.go

@@ -11,22 +11,22 @@ func TestEscapeAttrVal(t *testing.T) {
 		attrVal  string
 		expected string
 	}{
-		{"xyz", "xyz"},
-		{"", ""},
-		{"x&z", "x&z"},
-		{"x/z", "x/z"},
-		{"x'z", "\"x'z\""},
-		{"x\"z", "'x\"z'"},
-		{"'x\"z'", "'x\"z'"},
-		{"'x'\"'z'", "\"x'"'z\""},
-		{"\"x"'"z\"", "'x\"'\"z'"},
-		{"\"x'z\"", "\"x'z\""},
-		{"'x"z'", "'x\"z'"},
-		{"'x\">'", "'x\">'"},
-		{"You're encouraged to log in; however, it's not mandatory. [o]", "\"You're encouraged to log in; however, it's not mandatory. [o]\""},
-		{"a'b=\"\"", "'a'b=\"\"'"},
-		{"x<z", "\"x<z\""},
-		{"'x\"&#39;\"z'", "'x\"&#39;\"z'"},
+		{`xyz`, `xyz`},
+		{``, ``},
+		{`x&amp;z`, `x&amp;z`},
+		{`x/z`, `x/z`},
+		{`x'z`, `"x'z"`},
+		{`x"z`, `'x"z'`},
+		{`'x"z'`, `'x"z'`},
+		{`'x&#39;"&#39;z'`, `"x'&#34;'z"`},
+		{`"x&#34;'&#34;z"`, `'x"&#39;"z'`},
+		{`"x&#x27;z"`, `"x'z"`},
+		{`'x&#x00022;z'`, `'x"z'`},
+		{`'x"&gt;'`, `'x"&gt;'`},
+		{`You&#039;re encouraged to log in; however, it&#039;s not mandatory. [o]`, `"You're encouraged to log in; however, it's not mandatory. [o]"`},
+		{`a'b=""`, `'a&#39;b=""'`},
+		{`x<z`, `"x<z"`},
+		{`'x"&#39;"z'`, `'x"&#39;"z'`},
 	}
 	var buf []byte
 	for _, tt := range escapeAttrValTests {
@@ -36,7 +36,29 @@ func TestEscapeAttrVal(t *testing.T) {
 			if len(b) > 1 && (b[0] == '"' || b[0] == '\'') && b[0] == b[len(b)-1] {
 				b = b[1 : len(b)-1]
 			}
-			val := EscapeAttrVal(&buf, orig, []byte(b))
+			val := EscapeAttrVal(&buf, orig, []byte(b), false)
+			test.String(t, string(val), tt.expected)
+		})
+	}
+}
+
+func TestEscapeAttrValXML(t *testing.T) {
+	var escapeAttrValTests = []struct {
+		attrVal  string
+		expected string
+	}{
+		{`xyz`, `"xyz"`},
+		{``, `""`},
+	}
+	var buf []byte
+	for _, tt := range escapeAttrValTests {
+		t.Run(tt.attrVal, func(t *testing.T) {
+			b := []byte(tt.attrVal)
+			orig := b
+			if len(b) > 1 && (b[0] == '"' || b[0] == '\'') && b[0] == b[len(b)-1] {
+				b = b[1 : len(b)-1]
+			}
+			val := EscapeAttrVal(&buf, orig, []byte(b), true)
 			test.String(t, string(val), tt.expected)
 		})
 	}