From 99d2758343245de1ac452a9b8d1f4c1521f8c8d6 Mon Sep 17 00:00:00 2001
From: Stefan Monnier <monnier@iro.umontreal.ca>
Date: Wed, 2 May 2012 17:34:57 -0400
Subject: [PATCH] * subr.el (read-passwd): Better clean after ourselves.

Fixes: debbugs:11392
---
 lisp/ChangeLog |  4 ++++
 lisp/subr.el   | 29 ++++++++++++++++++-----------
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index d2ab4b60c8b..40df0618c0e 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,7 @@
+2012-05-02  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+	* subr.el (read-passwd): Better clean after ourselves (bug#11392).
+
 2012-05-02  Juanma Barranquero  <lekktu@gmail.com>
 
 	* notifications.el (dbus-debug):
diff --git a/lisp/subr.el b/lisp/subr.el
index b548f82ca5a..1f9f3aee9fa 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -2115,21 +2115,21 @@ by doing (clear-string STRING)."
               (message "Password not repeated accurately; please start over")
               (sit-for 1))))
         success)
-    (let (minibuf)
+    (let ((hide-chars-fun
+           (lambda (beg end _len)
+             (clear-this-command-keys)
+             (setq beg (min end (max (minibuffer-prompt-end)
+                                     beg)))
+             (dotimes (i (- end beg))
+               (put-text-property (+ i beg) (+ 1 i beg)
+                                  'display (string ?.)))))
+          minibuf)
       (minibuffer-with-setup-hook
           (lambda ()
             (setq minibuf (current-buffer))
             ;; Turn off electricity.
             (set (make-local-variable 'post-self-insert-hook) nil)
-            (add-hook 'after-change-functions
-                      (lambda (beg end _len)
-                        (clear-this-command-keys)
-                        (setq beg (min end (max (minibuffer-prompt-end)
-                                                beg)))
-                        (dotimes (i (- end beg))
-                          (put-text-property (+ i beg) (+ 1 i beg)
-                                             'display (string ?.))))
-                      nil t))
+            (add-hook 'after-change-functions hide-chars-fun nil 'local))
         (unwind-protect
             (read-string prompt nil
                          (let ((sym (make-symbol "forget-history")))
@@ -2137,7 +2137,14 @@ by doing (clear-string STRING)."
                            sym)
                          default)
           (when (buffer-live-p minibuf)
-            (with-current-buffer minibuf (erase-buffer))))))))
+            (with-current-buffer minibuf
+              ;; Not sure why but it seems that there might be cases where the
+              ;; minibuffer is not always properly reset later on, so undo
+              ;; whatever we've done here (bug#11392).
+              (remove-hook 'after-change-functions hide-chars-fun 'local)
+              (kill-local-variable 'post-self-insert-hook)
+              ;; And of course, don't keep the sensitive data around.
+              (erase-buffer))))))))
 
 ;; This should be used by `call-interactively' for `n' specs.
 (defun read-number (prompt &optional default)
-- 
2.39.2