Re: indent-new-comment-line misbehaviour?

I used xemacs-21.4.19 mule -vanilla. I added a comment via `lisp-indent-for-comment' (defun textmarker-region (start end) ;this is the comment (interactive "r") (xref-source-region start end) (xref-target-region start end)) however then indent-new-comment-line put the cursor (defun textmarker-region (start end) ;this is the comment ^ (interactive "r") (xref-source-region start end) (xref-target-region start end)) INSTEAD of (defun textmarker-region (start end) ;this is the comment ;^ (interactive "r") (xref-source-region start end) (xref-target-region start end)) However when I added more text into the first comment line (defun textmarker-region (start end) ;this is the comment but we need (interactive "r") (xref-source-region start end) (xref-target-region start end)) and used fill-paragraph I obtained (defun textmarker-region (start end) ;this is the comment ;but we need (interactive "r") (xref-source-region start end) (xref-target-region start end)) Which is find surprising. Can somebody please clarify me that issue.