1 files changed, 16 insertions, 6 deletions

diff --git a/lisp/compare-w.el b/lisp/compare-w.el
index a52e8e07541..a6bd00e1a07 100644
--- a/lisp/compare-w.el
+++ b/lisp/compare-w.el
@@ -134,19 +134,29 @@ If `compare-ignore-case' is non-nil, changes in case are also ignored."
 ;; and find the latest point at which a match ends.
 ;; Don't try starting points before START, though.
 ;; Value is non-nil if whitespace is found.
+
+;; If there is whitespace before point, but none after,
+;; then return t, but don't advance point.
 (defun compare-windows-skip-whitespace (start)
   (let ((end (point))
+        (beg (point))
         (opoint (point)))
-    (while (and (looking-at compare-windows-whitespace)
-                (<= end (match-end 0))
-                ;; This match goes past END, so advance END.
-                (progn (setq end (match-end 0))
-                       (> (point) start)))
+    (while (or (and (/= (point) start)
+                    ;; Consider at least the char before point,
+                    ;; unless it is also before START.
+                    (= (point) opoint))
+               (and (looking-at compare-windows-whitespace)
+                    (<= end (match-end 0))
+                    ;; This match goes past END, so advance END.
+                    (progn (setq end (match-end 0))
+                           (> (point) start))))
       ;; keep going back until whitespace
       ;; doesn't extend to or past end
       (forward-char -1))
+    (setq beg (point))
     (goto-char end)
-    (/= end opoint)))
+    (or (/= beg opoint)
+        (/= end opoint))))
 
 (provide 'compare-w)