[elpa] externals/denote 3a0bc9255b: Fix denote-org-extras--parse-rx for nil argument

[ELPA Syncer]

branch: externals/denote
commit 3a0bc9255bba92fc0ffa29054745852f71a29cec
Author: Protesilaos Stavrou <info@protesilaos.com>
Commit: Protesilaos Stavrou <info@protesilaos.com>

    Fix denote-org-extras--parse-rx for nil argument
    
    Thanks to Samuel Flint for noticing this problem as part of the
    discussion in issue 490: <https://github.com/protesilaos/denote/issues/490>.
---
 denote-org-extras.el | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/denote-org-extras.el b/denote-org-extras.el
index 9f1a546a6a..cc2086ee3f 100644
--- a/denote-org-extras.el
+++ b/denote-org-extras.el
@@ -429,7 +429,7 @@ Also see `denote-org-extras-dblock--files'."
   "Parse REGEXP as an `rx' argument or string and return string."
   (cond
    ((null regexp)
-    "")
+    nil)
    ((listp regexp)
     (rx-to-string regexp))
    ((stringp regexp)