-(defun-maybe base64-encode-region (start end)
- "Encode current region by base64.
-START and END are buffer positions.
+(defun-maybe base64-encode-region (start end &optional no-line-break)
+ "Base64-encode the region between START and END.
+Return the length of the encoded text.
+Optional third argument NO-LINE-BREAK means do not break long lines
+into shorter lines.