Add test case for issue #1703
Add test case for issue #1703

Add a test case for issue #1703 which John Wiegley fixed in commit
56025cde ("Don't attempt to invert a value if it's already zero").

afh/ledger,ledger/ledger,afh/ledger,ledger/ledger,afh/ledger,ledger/ledger,ledger/ledger,afh/ledger,afh/ledger,ledger/ledger