* lisp/epa.el (epa-read-file-name): New function.

(epa-decrypt-file): Make plain-file optional.  Use epa-read-file-name.

* doc/misc/epa.texi (Cryptographic operations on files): Update epa-decrypt-file.

Fixes: debbugs:14510

4 files changed, 27 insertions, 14 deletions

diff --git a/doc/misc/ChangeLog b/doc/misc/ChangeLog
index bcd3fe78ae8..ce2852e90f8 100644
--- a/doc/misc/ChangeLog
+++ b/doc/misc/ChangeLog
@@ -1,3 +1,7 @@
+2013-06-10  Glenn Morris  <rgm@gnu.org>
+
+        * epa.texi (Cryptographic operations on files): Update epa-decrypt-file.
+
 2013-06-04  Katsumi Yamaoka  <yamaoka@jpl.org>
 
         * gnus.texi (Article Date):
diff --git a/doc/misc/epa.texi b/doc/misc/epa.texi
index e21851ef37a..adc63cc0bdb 100644
--- a/doc/misc/epa.texi
+++ b/doc/misc/epa.texi
@@ -240,8 +240,9 @@ you answered yes, it will let you select the signing keys.
 @node Cryptographic operations on files
 @section Cryptographic operations on files
 
-@deffn Command epa-decrypt-file file
-Decrypt @var{file}.
+@deffn Command epa-decrypt-file file &optional output
+Decrypt @var{file}.  If you do not specify the name @var{output} to
+use for the decrypted file, this function prompts for the value to use.
 @end deffn
 
 @deffn Command epa-verify-file file
diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b7173c5cacf..02316659220 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2013-06-10  Glenn Morris  <rgm@gnu.org>
+
+        * epa.el (epa-read-file-name): New function.  (Bug#14510)
+        (epa-decrypt-file): Make plain-file optional.  Use epa-read-file-name.
+
 2013-06-09  Aidan Gauland  <aidalgol@amuri.net>
 
         * eshell/em-term.el (eshell-visual-command-p): Fix bug that caused
diff --git a/lisp/epa.el b/lisp/epa.el
index b567df5f40b..14f8879c1c6 100644
--- a/lisp/epa.el
+++ b/lisp/epa.el
@@ -620,21 +620,24 @@ If SECRET is non-nil, list secret keys instead of public keys."
                    (floor (* (/ current (float total)) 100))))
       (message "%s..." prompt))))
 
+(defun epa-read-file-name (input)
+  "Interactively read an output file name based on INPUT file name."
+  (setq input (file-name-sans-extension (expand-file-name input)))
+  (expand-file-name
+   (read-file-name
+    (concat "To file (default " (file-name-nondirectory input) ") ")
+    (file-name-directory input)
+    input)))
+
 ;;;###autoload
-(defun epa-decrypt-file (decrypt-file plain-file)
-  "Decrypt DECRYPT-FILE into PLAIN-FILE."
+(defun epa-decrypt-file (decrypt-file &optional plain-file)
+  "Decrypt DECRYPT-FILE into PLAIN-FILE.
+If you do not specify PLAIN-FILE, this functions prompts for the value to use."
   (interactive
-   (let (file default-name plain)
-     (setq file (read-file-name "File to decrypt: "))
-     (setq default-name (file-name-sans-extension (expand-file-name file)))
-     (setq plain (expand-file-name
-                  (read-file-name
-                   (concat "To file (default "
-                           (file-name-nondirectory default-name)
-                           ") ")
-                   (file-name-directory default-name)
-                   default-name)))
+   (let* ((file (read-file-name "File to decrypt: "))
+          (plain (epa-read-file-name file)))
      (list file plain)))
+  (or plain-file (setq plain-file (epa-read-file-name decrypt-file)))
   (setq decrypt-file (expand-file-name decrypt-file))
   (let ((context (epg-make-context epa-protocol)))
     (epg-context-set-passphrase-callback context