Fix handling of require-final-newline in after-find-file.

* files.el (after-find-file): Don't fail on a read-only buffer if
require-final-newline is `visit' or `visit-save'.

Fixes: debbugs:11156

lisp/ChangeLog

 2012-09-07  Chong Yidong  <cyd@gnu.org>
+	* files.el (after-find-file): Don't fail on a read-only buffer if
+	require-final-newline is `visit' or `visit-save' (Bug#11156).
+
 	* subr.el (read-char-choice): Allow quitting via ESC ESC.
 	* userlock.el (ask-user-about-supersession-threat): Use

lisp/files.el

@@ -2145,7 +2145,7 @@ unless NOMODES is non-nil."
 	 (not buffer-read-only)
 	 (save-excursion
 	   (goto-char (point-max))
-	   (insert "\n")))
+	   (ignore-errors (insert "\n"))))
     (when (and buffer-read-only
 	       view-read-only
 	       (not (eq (get major-mode 'mode-class) 'special)))