Better unicode conversion

gemini/processing.go

@@ -10,25 +10,25 @@ import (
 	"golang.org/x/text/transform"
 )
 
-func EnsureValidUTF8(input []byte) (string, error) {
-	// Remove NULL byte 0x00
-	inputNoNull := bytes.ReplaceAll(input, []byte{0}, nil)
+func BytesToValidUTF8(input []byte) (string, error) {
+	// Remove NULL byte 0x00 (ReplaceAll accepts slices)
+	inputNoNull := bytes.ReplaceAll(input, []byte{byte(0)}, []byte{})
 	isValidUTF8 := utf8.Valid(inputNoNull)
-	if !isValidUTF8 {
-		encodings := []transform.Transformer{
-			charmap.ISO8859_1.NewDecoder(),   // First try ISO8859-1
-			charmap.Windows1252.NewDecoder(), // Then try Windows-1252, etc
-			// TODO: Try more encodings?
-		}
-		// First successful conversion wins
-		for _, encoding := range encodings {
-			reader := transform.NewReader(bytes.NewReader(inputNoNull), encoding)
-			result, err := io.ReadAll(reader)
-			if err != nil {
-				return "", fmt.Errorf("UTF-8 error: %w", err)
-			}
+	if isValidUTF8 {
+		return string(inputNoNull), nil
+	}
+	encodings := []transform.Transformer{
+		charmap.ISO8859_1.NewDecoder(),   // First try ISO8859-1
+		charmap.Windows1252.NewDecoder(), // Then try Windows-1252, etc
+		// TODO: Try more encodings?
+	}
+	// First successful conversion wins.
+	for _, encoding := range encodings {
+		reader := transform.NewReader(bytes.NewReader(inputNoNull), encoding)
+		result, err := io.ReadAll(reader)
+		if err == nil {
 			return string(result), nil
 		}
 	}
-	return string(inputNoNull), nil
+	return "", fmt.Errorf("UTF-8 error: %w", err)
 }