From bcd67db4ab7a6514ca58c24db9e53a4c1b60da8b Mon Sep 17 00:00:00 2001
From: John D Pell <John+git@gaelicWizard.net>
Date: Sun, 25 Jul 2021 21:09:51 -0700
Subject: [PATCH] lib/preview: handle unbound parameter

If $BASH_PREVIEW is unset, treat it as blank.
---
 lib/preview.bash | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/preview.bash b/lib/preview.bash
index d0fb0623..418839cd 100644
--- a/lib/preview.bash
+++ b/lib/preview.bash
@@ -1,4 +1,4 @@
-if [[ $BASH_PREVIEW ]];
+if [[ "${BASH_PREVIEW:-}" ]];
 then
   unset BASH_PREVIEW #Prevent infinite looping
   echo "