new-buffer-auto-mode

;; hack that enable major mode for newly created buffer according to `auto-mode-alist'
(defadvice set-buffer-major-mode (after new-buffer-auto-mode activate compile)
  "Select major mode for newly created buffer.                                                                                
                                                                                                                              
Compare the `buffer-name' the entries in `auto-mode-alist'."
  (with-current-buffer (ad-get-arg 0)
    (if (and (buffer-name) (not buffer-file-name))
        (let ((name (buffer-name)))
          ;; Remove backup-suffixes from file name.                                                                           
          (setq name (file-name-sans-versions name))
          ;; Do not handle service buffers                                                                                    
          (while (and name (not (string-match "^\\*.+\\*$" name)))
            ;; Find first matching alist entry.                                                                               
            (setq mode
                  (if (memq system-type '(windows-nt cygwin))
                      ;; System is case-insensitive.                                                                          
                      (let ((case-fold-search t))
                        (assoc-default name auto-mode-alist
                                       'string-match))
                    ;; System is case-sensitive.                                                                              
                    (or
                     ;; First match case-sensitively.                                                                         
                     (let ((case-fold-search nil))
                       (assoc-default name auto-mode-alist
                                      'string-match))
                     ;; Fallback to case-insensitive match.                                                                   
                     (and auto-mode-case-fold
                          (let ((case-fold-search t))
                            (assoc-default name auto-mode-alist
                                           'string-match))))))
            (if (and mode
                     (consp mode)
                     (cadr mode))
                (setq mode (car mode)
                      name (substring name 0 (match-beginning 0)))
              (setq name nil))
            (when mode
              (set-auto-mode-0 mode t)))))))