# POSIX leaves the effect of NUL bytes in command substitution output
# unspecified but we have always discarded them.

failures=0

check() {
	if [ "$2" != "$3" ]; then
		printf "Failed at line %s: got \"%s\" expected \"%s\"\n" "$1" "$2" "$3"
		: $((failures += 1))
	fi
}

fmt='\0a\0 \0b\0c d\0'
assign_builtin=$(printf "$fmt")
check "$LINENO" "$assign_builtin" "a bc d"
assign_pipeline=$(printf "$fmt" | cat)
check "$LINENO" "$assign_pipeline" "a bc d"
set -- $(printf "$fmt") $(printf "$fmt" | cat) "$(printf "$fmt")" "$(printf "$fmt" | cat)" 
IFS=@
splits="$*"
check "$LINENO" "$splits" "a@bc@d@a@bc@d@a bc d@a bc d"

[ "$failures" = 0 ]