shell: remove ${#+} tests, it is not a valid construct

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/shell/ash_test/ash-vars/param_expand_alt.tests b/shell/ash_test/ash-vars/param_expand_alt.tests
index d804524..23e9a26 100755
--- a/shell/ash_test/ash-vars/param_expand_alt.tests
+++ b/shell/ash_test/ash-vars/param_expand_alt.tests
@@ -6,8 +6,13 @@
 # now some funky ones.
 # ${V+word} "if V unset, then substitute nothing, else substitute word"
 # ${V:+word} "if V unset or '', then substitute nothing, else substitute word"
-# bash doesn't accept ${#+}. ash prints 0 (not $#): "len of $+"
-echo _${#+}_ _${#:+}_
+#
+# ${#:+} is a :+ op on $#, but ${#+} (and any other ${#c}) is "length of $c",
+# not + op on $#.
+# bash and dash do not accept ${#+}. it's possible for some shell to skip
+# the check that c is valid and interpret ${#+} as "len of $+". Not testing it.
+# echo _${#+}_
+echo _${#:+}_
 # Forms with non-empty word work as expected in both ash and bash.
 echo _${#+z}_ _${#:+z}_