=== modified file 'lisp/ChangeLog'
--- lisp/ChangeLog	2012-10-11 20:39:05 +0000
+++ lisp/ChangeLog	2012-10-12 16:08:17 +0000
@@ -1,3 +1,10 @@
+2012-10-12  Jambunathan K  <kjambunathan@gmail.com>
+
+	* hi-lock.el (hi-lock-unface-buffer): Prompt user with useful
+	defaults.  Specifically, if cursor is on an highlighted text,
+	offer a regexp that matches that text as the default.  Update
+	docstring.
+
 2012-10-11  Jambunathan K  <kjambunathan@gmail.com>
 
 	* replace.el (read-regexp): Tighten the regexp that matches tag.

=== modified file 'lisp/hi-lock.el'
--- lisp/hi-lock.el	2012-10-11 20:39:05 +0000
+++ lisp/hi-lock.el	2012-10-12 15:55:49 +0000
@@ -493,8 +493,15 @@ updated as you type."
 ;;;###autoload
 (defun hi-lock-unface-buffer (regexp)
   "Remove highlighting of each match to REGEXP set by hi-lock.
-Interactively, prompt for REGEXP, accepting only regexps
-previously inserted by hi-lock interactive functions."
+Interactively, prompt for REGEXP.  If the cursor is on a
+previously highlighted text and if the associated regexp can be
+inferred via simple heuristics, offer that regexp as default.
+Otherwise, prompt for REGEXP with completion and limit the
+choices to only those regexps used previously with hi-lock
+commands.
+
+If this command is invoked via menu, make no attempt to infer
+REGEXP from text at point."
   (interactive
    (if (and (display-popup-menus-p)
 	    (listp last-nonmenu-event)
@@ -522,15 +529,51 @@ previously inserted by hi-lock interacti
 	  ;; To prevent that, we return an empty string, which will
 	  ;; effectively disable the rest of the function.
 	  (throw 'snafu '(""))))
-     (let ((history-list (mapcar (lambda (p) (car p))
-                                 hi-lock-interactive-patterns)))
+     ;; Un-highlighting triggered via keyboard action.
        (unless hi-lock-interactive-patterns
          (error "No highlighting to remove"))
+     ;; Infer the regexp to un-highlight based on cursor position.
+     (let* (candidate-hi-lock-patterns
+	    (default-regexp
+	      (or
+	       ;; When using overlays, there is no ambiguity on the best
+	       ;; choice of regexp.
+	       (let ((desired-serial (get-char-property
+				      (point) 'hi-lock-overlay-regexp)))
+		 (when desired-serial
+		   (catch 'regexp
+		     (maphash
+		      (lambda (regexp serial)
+			(when (= serial desired-serial)
+			  (throw 'regexp regexp)))
+		      hi-lock-string-serialize-hash))))
+	       ;; With font-locking on, check if the cursor is on an
+	       ;; highlighted text.  Checking for hi-lock face is a
+	       ;; good heuristic.
+	       (and (string-match "\\`hi-lock-" (face-name (face-at-point)))
+		    (let* ((hi-text
+			    (buffer-substring-no-properties
+			     (previous-single-property-change (point) 'face)
+			     (next-single-property-change (point) 'face))))
+		      ;; Compute hi-lock patterns that match the
+		      ;; highlighted text at point.  Use this later in
+		      ;; during completing-read.
+		      (setq candidate-hi-lock-patterns
+			    (delq nil
+				  (mapcar
+				   (lambda (hi-lock-pattern)
+				     (let ((regexp (car hi-lock-pattern)))
+				       (and (string-match regexp hi-text)
+					    hi-lock-pattern)))
+				   hi-lock-interactive-patterns)))
+		      ;; Use regexp from the first matching pattern as
+		      ;; a reasonable default.
+		      (caar candidate-hi-lock-patterns))))))
        (list
         (completing-read "Regexp to unhighlight: "
-                         hi-lock-interactive-patterns nil t
-                         (car (car hi-lock-interactive-patterns))
-                         (cons 'history-list 1))))))
+			 (or candidate-hi-lock-patterns
+			     hi-lock-interactive-patterns)
+			 nil t default-regexp)))))
   (let ((keyword (assoc regexp hi-lock-interactive-patterns)))
     (when keyword
       (font-lock-remove-keywords nil (list keyword))