1 files changed, 23 insertions, 11 deletions

diff --git a/lisp/server.el b/lisp/server.el
index 9dcd1f3b1d9..34ac5d7ba23 100644
--- a/lisp/server.el
+++ b/lisp/server.el
@@ -126,6 +126,8 @@ port number."
 
 (defcustom server-auth-dir (locate-user-emacs-file "server/")
   "Directory for server authentication files.
+We only use this if `server-use-tcp' is non-nil.
+Otherwise we use `server-socket-dir'.
 
 NOTE: On FAT32 filesystems, directories are not secure;
 files can be read and modified by any user or process.
@@ -397,16 +399,19 @@ If CLIENT is non-nil, add a description of it to the logged message."
     ;; visible.  If not (which can happen if the user's customizations call
     ;; pop-to-buffer etc.), delete it to avoid preserving the connection after
     ;; the last real frame is deleted.
-    (if (and (eq (frame-first-window frame)
-                 (next-window (frame-first-window frame) 'nomini))
-             (eq (window-buffer (frame-first-window frame))
-                 (frame-parameter frame 'server-dummy-buffer)))
-        ;; The temp frame still only shows one buffer, and that is the
-        ;; internal temp buffer.
-        (delete-frame frame)
-      (set-frame-parameter frame 'visibility t))
-    (kill-buffer (frame-parameter frame 'server-dummy-buffer))
-    (set-frame-parameter frame 'server-dummy-buffer nil)))
+
+    ;; Rewritten to avoid inadvertently killing the current buffer after
+    ;; `delete-frame' removed FRAME (Bug#10729).
+    (let ((buffer (frame-parameter frame 'server-dummy-buffer)))
+      (if (and (one-window-p 'nomini frame)
+               (eq (window-buffer (frame-first-window frame)) buffer))
+          ;; The temp frame still only shows one buffer, and that is the
+          ;; internal temp buffer.
+          (delete-frame frame)
+        (set-frame-parameter frame 'visibility t)
+        (set-frame-parameter frame 'server-dummy-buffer nil))
+      (when (buffer-live-p buffer)
+        (kill-buffer buffer)))))
 
 (defun server-handle-delete-frame (frame)
   "Delete the client connection when the emacsclient frame is deleted.
@@ -1525,7 +1530,14 @@ only these files will be asked to be saved."
   nil)
 
 (defun server-eval-at (server form)
-  "Eval FORM on Emacs Server SERVER."
+  "Contact the Emacs server named SERVER and evaluate FORM there.
+Returns the result of the evaluation, or signals an error if it
+cannot contact the specified server.  For example:
+  \(server-eval-at \"server\" '(emacs-pid))
+returns the process ID of the Emacs instance running \"server\".
+This function requires the use of TCP sockets. "
+  (or server-use-tcp
+      (error "This function requires TCP sockets"))
   (let ((auth-file (expand-file-name server server-auth-dir))
         (coding-system-for-read 'binary)
         (coding-system-for-write 'binary)