Eshell/Shell: Default to `M-x shell' in shell switcher.

.emacs.d/lisp/init-eshell.el

@@ -216,6 +216,8 @@ This should be faster then `seq-uniq'."
 ;; (add-hook 'eshell-mode-hook 'ambrevar/fix-local-epa-file-encrypt-to)
 
 ;;; Spawning
+(defvar ambrevar/prefer-eshell nil
+  "If non-nil, default to Eshell instead of M-x shell.")
 (when (require 'patch-helm nil 'noerror)
   (helm-defswitcher
    "Eshell"
@@ -225,10 +227,14 @@ This should be faster then `seq-uniq'."
         (derived-mode-p 'eshell-mode)
         (derived-mode-p 'shell-mode))))
    (lambda (&optional name)
-     ;; TODO: Could add an option "prefer-eshell" to choose between Eshell/Shell by default.
-     (eshell 'new)
+     (if ambrevar/prefer-eshell
+         (eshell 'new)
+       (shell (generate-new-buffer (generate-new-buffer-name "*shell*"))))
      (when name
-       (rename-buffer (format "*eshell<%s>*" name) 'unique)))
+       (rename-buffer (format "*%sshell<%s>*"
+                              (if ambrevar/prefer-eshell "e" "")
+                              name)
+                      'unique)))
    nil
    (helm-build-dummy-source
        "Create shell buffer"