lang/plantuml: force ob-plantuml to build w/ plantuml-mode

It is more sophisticated and robust.

modules/lang/plantuml/config.el

@@ -1,12 +1,17 @@
 ;;; lang/plantuml/config.el -*- lexical-binding: t; -*-
 
 (use-package! plantuml-mode
-  :defer t
+  :commands plantuml-download-jar
   :init
   (setq plantuml-jar-path (concat doom-etc-dir "plantuml.jar")
         org-plantuml-jar-path plantuml-jar-path)
   :config
-  (set-popup-rule! "^\\*PLANTUML" :size 0.4 :select nil :ttl 0))
+  (set-popup-rule! "^\\*PLANTUML" :size 0.4 :select nil :ttl 0)
+
+  (setq plantuml-default-exec-mode
+        (cond ((executable-find "plantuml") 'executable)
+              ((file-exists-p plantuml-jar-path) 'jar)
+              (plantuml-default-exec-mode))))
 
 
 (use-package! flycheck-plantuml
@@ -16,19 +21,9 @@
 
 
 (after! ob-plantuml
-  (defadvice! +plantuml--fix-atstart-in-org-src-blocks-a (args)
-    "Fix error when executing plantuml src blocks in org-mode for code that
-begins with '@'. This character needs to be escaped with a backslash or comma
-for the block to execute correctly, so we do it automatically."
-    :filter-args #'org-babel-execute:plantuml
-    (cl-destructuring-bind (body params) args
-      (let* ((origin-body body)
-             (fix-body
-              (replace-regexp-in-string
-               "^[[:blank:]\n]*\\(@start\\)"
-               "\\\\\\1"
-               origin-body)))
-        (list fix-body params))))
-
+  ;; HACK We force ob-plantuml to use `plantuml-mode''s building mechanism,
+  ;; which is more sophisticated.
+  (advice-add #'org-babel-execute:plantuml
+              :override #'+plantuml-org-babel-execute:plantuml-a)
   (add-to-list 'org-babel-default-header-args:plantuml
                '(:cmdline . "-charset utf-8")))