From f2115f5587c7765d8846fab382b00aceff3270e6 Mon Sep 17 00:00:00 2001
From: Daniel Borchmann <daniel@algebra20.de>
Date: Fri, 31 May 2019 21:38:05 +0200
Subject: [PATCH] [Org] A custom link type for RFCs

---
 init.el               | 6 +++++-
 site-lisp/db-utils.el | 7 +++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/init.el b/init.el
index 19ed725..8d98d58 100644
--- a/init.el
+++ b/init.el
@@ -569,7 +569,8 @@ search commands like `db/helm-shortcuts’."
              db/bookmark-add-url
              db/lookup-smime-key
              db/org-onenote-open
-             db/org-outlook-open))
+             db/org-outlook-open
+             db/org-rfc-open))
 
 (use-package hydra
   :commands (defhydra))
@@ -782,6 +783,9 @@ search commands like `db/helm-shortcuts’."
             ;; Skip some org mode regions to be skipped by ispell
             (add-hook 'org-mode-hook #'endless/org-ispell)
 
+            ;; Link type for RFCs
+            (org-link-set-parameters "rfc" :follow #'db/org-rfc-open)
+
             ;; Some timers
 
             (unless (memq #'org-clock-save
diff --git a/site-lisp/db-utils.el b/site-lisp/db-utils.el
index 359ae37..750223b 100644
--- a/site-lisp/db-utils.el
+++ b/site-lisp/db-utils.el
@@ -519,6 +519,13 @@ This is done only if the value of this variable is not null."
   (unless (file-executable-p db/path-to-outlook)
     (user-error "Path for Outlook is not executable, please customize `db/path-to-outlook’."))
   (w32-shell-execute "open" db/path-to-outlook (concat "/select outlook:" id)))
+
+(defun db/org-rfc-open (number)
+  "Open browser to show RFC of given NUMBER."
+  (unless (string-match "[1-9][0-9]*" number)
+    (user-error "Not a valid number for an RFC: %s" number))
+  (browse-url (concat "https://tools.ietf.org/html/rfc" number)))
+
 
 ;;; Bookmarks