preserve traps across a failed exec; small changes to how completion options interact; fix a bug with arithmetic for commands and LINENO

tests/array15.sub

@@ -35,3 +35,18 @@ func()
 
 func
 echo "${foo[@]}" 
+
+unset foo
+
+# test options to declare that disable attributes that affect how values
+# are expanded
+#
+# we already handle options that set attributes specially, so we should
+# handle attributes that unset those attributes specially as well
+
+unset arr
+declare -i -a arr=(1+1 2+2 3+3)
+declare -p arr 
+
+declare +i arr=(hello world)
+declare -p arr