epg: Support pinentry-curses

2 files changed, 46 insertions, 2 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 34cb50bb44c..c4d884a5010 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,13 @@
+2012-12-28  Daiki Ueno  <ueno@gnu.org>
+
+        * epg.el: Support pinentry-curses.
+        Suggested by Werner Koch in
+        <http://lists.gnu.org/archive/html/emacs-devel/2007-02/msg00755.html>.
+        (epg-agent-file, epg-agent-mtime): New variable.
+        (epg--start): Record the modified time of gpg-agent socket file,
+        to restore Emacs frame after pinentry-curses termination.
+        (epg-wait-for-completion): Restore Emacs frame here.
+
 2012-12-27  Juri Linkov  <juri@jurta.org>
 
         * info.el (Info-file-completions): New variable.
diff --git a/lisp/epg.el b/lisp/epg.el
index 280c24616f2..5fb8f809aa9 100644
--- a/lisp/epg.el
+++ b/lisp/epg.el
@@ -37,6 +37,8 @@
 (defvar epg-key-id nil)
 (defvar epg-context nil)
 (defvar epg-debug-buffer nil)
+(defvar epg-agent-file nil)
+(defvar epg-agent-mtime nil)
 
 ;; from gnupg/include/cipher.h
 (defconst epg-cipher-algorithm-alist
@@ -1156,7 +1158,28 @@ This function is for internal use only."
          process-connection-type
          (orig-mode (default-file-modes))
          (buffer (generate-new-buffer " *epg*"))
-         process)
+         process
+         terminal-name
+         agent-file
+         (agent-mtime '(0 0 0 0)))
+    ;; Set GPG_TTY and TERM for pinentry-curses.  Note that we can't
+    ;; use `terminal-name' here to get the real pty name for the child
+    ;; process, though /dev/fd/0" is not portable.
+    (with-temp-buffer
+      (when (= (call-process "tty" "/dev/fd/0" t) 0)
+        (delete-backward-char 1)
+        (setq terminal-name (buffer-string))))
+    (when terminal-name
+      (setenv "GPG_TTY" terminal-name)
+      (setenv "TERM" "xterm"))
+    ;; Record modified time of gpg-agent socket to restore the Emacs
+    ;; frame on text terminal in `epg-wait-for-completion'.
+    ;; See
+    ;; <http://lists.gnu.org/archive/html/emacs-devel/2007-02/msg00755.html>
+    ;; for more details.
+    (when (and agent-info (string-match "\\(.*\\):[0-9]+:[0-9]+" agent-info))
+      (setq agent-file (match-string 1 agent-info)
+            agent-mtime (or (nth 5 (file-attributes agent-file)) '(0 0 0 0))))
     (if epg-debug
         (save-excursion
           (unless epg-debug-buffer
@@ -1185,7 +1208,11 @@ This function is for internal use only."
       (make-local-variable 'epg-key-id)
       (setq epg-key-id nil)
       (make-local-variable 'epg-context)
-      (setq epg-context context))
+      (setq epg-context context)
+      (make-local-variable 'epg-agent-file)
+      (setq epg-agent-file agent-file)
+      (make-local-variable 'epg-agent-mtime)
+      (setq epg-agent-mtime agent-mtime))
     (unwind-protect
         (progn
           (set-default-file-modes 448)
@@ -1262,6 +1289,13 @@ This function is for internal use only."
     (accept-process-output (epg-context-process context) 1))
   ;; This line is needed to run the process-filter right now.
   (sleep-for 0.1)
+  ;; Restore Emacs frame on text terminal, when pinentry-curses has terminated.
+  (if (with-current-buffer (process-buffer (epg-context-process context))
+        (and epg-agent-file
+             (> (float-time (or (nth 5 (file-attributes epg-agent-file))
+                                '(0 0 0 0)))
+                (float-time epg-agent-mtime))))
+      (redraw-frame))
   (epg-context-set-result-for
    context 'error
    (nreverse (epg-context-result-for context 'error))))