minimal vend

vendor/github.com/mmcdole/gofeed/internal/shared/xmlsanitizer.go

@@ -0,0 +1,23 @@
+package shared
+
+import (
+	"io"
+
+	"golang.org/x/text/transform"
+)
+
+// NewXMLSanitizerReader creates an io.Reader that
+// wraps another io.Reader and removes illegal xml
+// characters from the io stream.
+func NewXMLSanitizerReader(xml io.Reader) io.Reader {
+	isIllegal := func(r rune) bool {
+		return !(r == 0x09 ||
+			r == 0x0A ||
+			r == 0x0D ||
+			r >= 0x20 && r <= 0xDF77 ||
+			r >= 0xE000 && r <= 0xFFFD ||
+			r >= 0x10000 && r <= 0x10FFFF)
+	}
+	t := transform.Chain(transform.RemoveFunc(isIllegal))
+	return transform.NewReader(xml, t)
+}