Improve buffer name default for C-u M-x shell.

* shell.el (shell): For C-u M-x shell, use an inactive shell
buffer as the default.

Fixes: debbugs:1975

2 files changed, 11 insertions, 1 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 5740d796f3e..4a128e10925 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2012-11-30  Chong Yidong  <cyd@gnu.org>
+
+        * shell.el (shell): For C-u M-x shell, use an inactive shell
+        buffer as the default (Bug#1975).
+
 2012-11-30  Yuriy Vostrikov  <delamonpansie@gmail.com>  (tiny change)
 
         * vc/vc-git.el (vc-git-command): Disable the pager (Bug#6137).
diff --git a/lisp/shell.el b/lisp/shell.el
index 77a42389785..38273311b61 100644
--- a/lisp/shell.el
+++ b/lisp/shell.el
@@ -671,7 +671,12 @@ Otherwise, one argument `-i' is passed to the shell.
     (and current-prefix-arg
          (prog1
              (read-buffer "Shell buffer: "
-                          (generate-new-buffer-name "*shell*"))
+                          ;; If the current buffer is an inactive
+                          ;; shell buffer, use it as the default.
+                          (if (and (eq major-mode 'shell-mode)
+                                   (null (get-buffer-process (current-buffer))))
+                              (buffer-name)
+                            (generate-new-buffer-name "*shell*")))
            (if (file-remote-p default-directory)
                ;; It must be possible to declare a local default-directory.
                ;; FIXME: This can't be right: it changes the default-directory