From b9038d045ee47a17e90343d2e01772ef3b5a5351 Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Sun, 21 Feb 2021 06:09:30 +0100
Subject: [PATCH] Fix error when `ZSH_VERSION` is unset.

Merges https://github.com/espressif/esp-idf/pull/6587
---
 export.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/export.sh b/export.sh
index 56ee1ff66a..a7ee837807 100644
--- a/export.sh
+++ b/export.sh
@@ -141,7 +141,7 @@ idf_export_main() {
 }
 
 enable_autocomplete() {
-    if [ -n "$ZSH_VERSION" ]
+    if [ -n "${ZSH_VERSION-}" ]
     then
         autoload -Uz compinit && compinit -u
         eval "$(env _IDF.PY_COMPLETE=source_zsh idf.py)" || echo "WARNING: Failed to load shell autocompletion!"