hush: fix a=abc; c=c; echo ${a%${c}}

hush: fix a=abc; c=c; echo ${a%${c}}

function                                             old     new   delta
expand_vars_to_list                                 2229    2302     +73
add_till_closing_paren                               286     313     +27
handle_dollar                                        623     574     -49
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 100/-49)            Total: 51 bytes

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