[__sensible_editor] Allow to omit the --editor parameter if --state is absent

cdist/conf/type/__sensible_editor/explorer/editor_path

@@ -33,6 +33,9 @@ editor_no_alternative() {
 		"$(test "${editors}" && echo "\nPlease choose one of:\n\n${editors}")"
 }
 
+# No need to check for the path if the file is supposed to be removed.
+test "$(cat "${__object}/parameter/state")" != 'absent' || exit 0
+
 
 case $("${__explorer}/os")
 in
@@ -50,7 +53,9 @@ in
 		;;
 esac
 
-editor=$(cat "${__object}/parameter/editor")
+# Read --editor parameter and check its value since it is "optional"
+editor=$(cat "${__object}/parameter/editor" 2>/dev/null) || true
+test -n "${editor}" || die 'Please provide an --editor to configure.'
 
 case $editor
 in

cdist/conf/type/__sensible_editor/man.rst

@@ -18,6 +18,8 @@ editor
     Name or path of the editor to be selected.
     On systems other than Debian derivatives an absolute path is required.
 
+	It is permissible to omit this parameter if --state is absent.
+
 
 OPTIONAL PARAMETERS
 -------------------

cdist/conf/type/__sensible_editor/parameter/optional

@@ -1 +1,2 @@
+editor
 state

cdist/conf/type/__sensible_editor/parameter/required

@@ -1 +0,0 @@
-editor