[type/__uci_commit] Move uncommited changes check from explorer to code-remote

This is done to prevent false positives/negatives (see NOTE in code)

cdist/conf/type/__uci_commit/explorer/changes

@@ -1,22 +0,0 @@
-#!/bin/sh
-#
-# 2020 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
-#
-# This file is part of cdist.
-#
-# cdist is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# cdist is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with cdist. If not, see <http://www.gnu.org/licenses/>.
-#
-# This explorer outputs the uncommited UCI changes on the target.
-
-uci changes

cdist/conf/type/__uci_commit/gencode-remote

@@ -23,19 +23,28 @@ batchfile="${__global:?}/tmp/__uci/${transaction_name}.txt"
 
 test -s "${batchfile}" || exit 0
 
-if test -s "${__object:?}/explorer/changes"
+printf 'commit transaction %s\n' "${transaction_name}" >>"${__messages_out:?}"
+
+# NOTE: Uncommited changes are checked in code-remote instead of in an explorer
+#       because in cdist there is no interlocking between explorers and code
+#       execution.
+#       Checking for uncommited changes in an explorer leaves a time slot in
+#       which changes made are not detected by the code.
+#       Furthermore an explorer running concurrently with another transactions
+#       code-remote could lead to a false positive.
+
+cat <<CODE
+changes=\$(uci changes)
+
+if test -n "\${changes}"
 then
 	echo 'Uncommited UCI changes were found on the target:'
-	cat "${__object:?}/explorer/changes"
+	printf '%s\n\n' "\${changes}"
-	echo
 	echo 'This can be caused by manual changes or due to a previous failed run.'
 	echo 'Please investigate the situation, revert or commit the changes, and try again.'
 	exit 1
 fi >&2
 
-printf 'commit transaction %s\n' "${transaction_name}" >>"${__messages_out:?}"
-
-cat <<CODE
 rollback() {
 	uci changes \\
 	| sed -e 's/\..*\$//' -e 's/^-//' \\