From 8237e61ab26e61025be9ae197d2d5170574d20bb Mon Sep 17 00:00:00 2001
From: Achim Gsell <achim.gsell@psi.ch>
Date: Thu, 9 Dec 2021 18:02:40 +0100
Subject: [PATCH] modulecmd: restrict removing overlays to top on stack

---
 Pmodules/modulecmd.bash.in | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Pmodules/modulecmd.bash.in b/Pmodules/modulecmd.bash.in
index 8c7d659..b0a5562 100644
--- a/Pmodules/modulecmd.bash.in
+++ b/Pmodules/modulecmd.bash.in
@@ -1656,6 +1656,14 @@ subcommand_unuse() {
                                          "not an used overlay" \
                                          "${ol_name_or_dir%:*}"
 				
+			# make sure first index is '0' (it should, but you never know)
+			OverlayList=( "${OverlayList[@]}" )
+			[[ "${ol_dir}" != "${OverlayList[0]}" ]] && \
+				std::die 3 "%s %s: %s %s -- %s" \
+					 "${CMD}" "${subcommand}" \
+					 "overlay cannot be removed since" \
+					 "it not on top of the stack" \
+					 "${ol_name_or_dir%:*}"
 			if [[ "${OverlayDict[${ol_dir}]}" == "${ol_replacing}" ]]; then
 				# if this overlay hides groups, we have to re-add
 				# the modules made available by other overlays