[Fix #1453] Re-enable auto-save-mode

- Re-enable
- Move all autosave files to spacemacs-cache-directory
- Allow Auto-saving directly on current buffer.
- Add option to customize.
- Update .spacemacs template.

core/core-dotspacemacs.el

@@ -87,6 +87,10 @@ with `:' and Emacs commands are executed with `<leader> :'.")
   "If non nil then `ido' replaces `helm' for some commands. For now only
 `find-files' (SPC f f) is replaced.")
 
+(defvar dotspacemacs-autosave-file-directly nil
+  "If non-nil, auto-save to the file directly. If nil, just save
+to auto-save file in `spacemacs-cache-directory'")
+
 (defvar dotspacemacs-enable-paste-micro-state t
   "If non nil the paste micro-state is enabled. While enabled pressing `p`
 several times cycle between the kill ring content.'")

core/templates/.spacemacs.template

@@ -96,6 +96,9 @@ before layers configuration."
    ;; By default the command key is `:' so ex-commands are executed like in Vim
    ;; with `:' and Emacs commands are executed with `<leader> :'.
    dotspacemacs-command-key ":"
+   ;; If non-nil, auto-save to the file directly. If nil, just save
+   ;; to auto-save file in `spacemacs-cache-directory'
+   dotspacemacs-autosave-file-directly nil
    ;; If non nil then `ido' replaces `helm' for some commands. For now only
    ;; `find-files' (SPC f f) is replaced.
    dotspacemacs-use-ido nil

spacemacs/config.el

@@ -214,11 +214,14 @@ Can be installed with `brew install trash'."
 (setq custom-file (dotspacemacs/location))
 ;; scratch buffer empty
 (setq initial-scratch-message nil)
-;; don't create backup~ or #auto-save# files
+;; don't create backup~ files
 (setq backup-by-copying t
       make-backup-files nil
-      auto-save-default nil
       create-lockfiles nil)
+
+(setq auto-save-file-name-transforms `((".*" ,spacemacs-cache-directory t)))
+(add-hook 'auto-save-hook 'save-buffer-if-visiting-file)
+
 (require 'uniquify)
 ;; When having windows with repeated filenames, uniquify them
 ;; by the folder they are in rather those annoying <2>,<3>,.. etc

spacemacs/funcs.el

@@ -1008,3 +1008,10 @@ the right."
 (create-align-repeat-x "left-paren" "(")
 (create-align-repeat-x "right-paren" ")" t)
 
+(defun save-buffer-if-visiting-file (&optional args)
+  "Save the current buffer only if it is visiting a file"
+  (interactive)
+  (if (and dotspacemacs-autosave-file-directly
+           (buffer-file-name)
+           (buffer-modified-p))
+      (save-buffer args)))