cl-macs `loop' fix for bug#7492.

* lisp/emacs-lisp/cl-macs.el (cl-parse-loop-clause):
Avoid infinite loop over windows.

2 files changed, 14 insertions, 2 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 135cfe952c7..502a6c65f42 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,8 @@
 2010-12-02  Glenn Morris  <rgm@gnu.org>
 
+        * emacs-lisp/cl-macs.el (cl-parse-loop-clause):
+        Avoid infinite loop over windows.  (Bug#7492)
+
         * progmodes/flymake.el (flymake-check-file-limit):
         Allow nil to mean "no limit".
         (flymake-check-patch-master-file-buffer): Update for above change.
diff --git a/lisp/emacs-lisp/cl-macs.el b/lisp/emacs-lisp/cl-macs.el
index 76f677c6198..725b98354af 100644
--- a/lisp/emacs-lisp/cl-macs.el
+++ b/lisp/emacs-lisp/cl-macs.el
@@ -965,16 +965,25 @@ Valid clauses are:
 
                ((memq word '(window windows))
                 (let ((scr (and (memq (car loop-args) '(in of)) (cl-pop2 loop-args)))
-                      (temp (make-symbol "--cl-var--")))
+                      (temp (make-symbol "--cl-var--"))
+                      (minip (make-symbol "--cl-minip--")))
                   (push (list var (if scr
                                       (list 'frame-selected-window scr)
                                     '(selected-window)))
                         loop-for-bindings)
+                  ;; If we started in the minibuffer, we need to
+                  ;; ensure that next-window will bring us back there
+                  ;; at some point.  (Bug#7492).
+                  ;; (Consider using walk-windows instead of loop if
+                  ;; you care about such things.)
+                  (push (list minip `(minibufferp (window-buffer ,var)))
+                        loop-for-bindings)
                   (push (list temp nil) loop-for-bindings)
                   (push (list 'prog1 (list 'not (list 'eq var temp))
                               (list 'or temp (list 'setq temp var)))
                         loop-body)
-                  (push (list var (list 'next-window var)) loop-for-steps)))
+                  (push (list var (list 'next-window var minip))
+                        loop-for-steps)))
 
                (t
                 (let ((handler (and (symbolp word)