(etags-file-of-tag): Handle file name used as tag.

lisp/progmodes/etags.el

@@ -997,9 +997,12 @@ See documentation of variable `tags-file-name'."
 
 (defun etags-file-of-tag ()
   (save-excursion
-    (re-search-backward "\f\n\\([^\n]+\\),[0-9]*\n")
+    (if (looking-at "./")
+        (re-search-forward "\\([^\n]+\\),[0-9]*\n")
+      (re-search-backward "\f\n\\([^\n]+\\),[0-9]*\n"))
     (buffer-substring (match-beginning 1) (match-end 1))))
 
+
 (defun etags-tags-completion-table ()
   (let ((table (make-vector 511 0)))
     (save-excursion