Attach PDF from ebib to email in mu4e/gnus

ebib-attach-file.el

(defun ebib-attach-file ()
  "Attach file to gnus/mu4e composition buffer"
  (interactive)

  (ebib-execute-when
    ((entries)
     (let ((filename (to-raw (car (ebib-get-field-value ebib-standard-file-field
                                                        (edb-cur-entry ebib-cur-db))))))
       (if filename
           (ebib-dired-attach filename)
         (error "Field `%s' is empty" ebib-standard-file-field))))
    ((default)
     (beep))))

(defun ebib-dired-attach (file)
  "Attach FILENAME using gnus-dired-attach."
  (let ((file-full-path
            (or (locate-file file ebib-file-search-dirs)
                (locate-file (file-name-nondirectory file) ebib-file-search-dirs)
                (expand-file-name file))))
    (if (file-exists-p file-full-path)
	(progn
	  (gnus-dired-attach (cons file-full-path '()))
	  (ebib-lower))
      (error "File not found: `%s'" file-full-path))))