Assert tripped in LedgerEntrySet when orders cross

[justmoon]

Steps to reproduce:

1. Create a new ledger, no peers.
2. God creates one order, buy 10 BTC/god for 15 USD/god each.
3. God creates another order, sell 10 BTC/god for 15 USD/god each.

Expected result:
Either the offers cancel each other with no effect, or perhaps an error stating that god does not have the necessary trust lines to pay himself.

Actual result:
Server stops because of assert.

Stack:

Program received signal SIGABRT, Aborted.
[Switching to Thread 0x7fffeffff700 (LWP 8479)]
0x00007ffff5775425 in __GI_raise (sig=<optimized out>)
    at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
64  ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0  0x00007ffff5775425 in __GI_raise (sig=<optimized out>)
    at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1  0x00007ffff5778b8b in __GI_abort () at abort.c:91
#2  0x00007ffff576e0ee in __assert_fail_base (fmt=<optimized out>, 
    assertion=0x100527c "false", 
    file=0x1005248 "src/cpp/ripple/LedgerEntrySet.cpp", line=<optimized out>, 
    function=<optimized out>) at assert.c:94
#3  0x00007ffff576e192 in __GI___assert_fail (assertion=0x100527c "false", 
    file=0x1005248 "src/cpp/ripple/LedgerEntrySet.cpp", line=96, 
    function=0x1009540 <LedgerEntrySet::entryCache(LedgerEntryType, uint256 const&)::__PRETTY_FUNCTION__> "SerializedLedgerEntry::pointer LedgerEntrySet::entryCache(LedgerEntryType, const uint256&)") at assert.c:103
#4  0x0000000000c1d05b in LedgerEntrySet::entryCache (this=0x150bc70, 
    letType=ltDIR_NODE, index=...) at src/cpp/ripple/LedgerEntrySet.cpp:96
#5  0x0000000000c20f1a in LedgerEntrySet::dirAdd(unsigned long long&, uint256 const&, uint256 const&, boost::function<void (boost::shared_ptr<SerializedLedgerEntry> const&)>) (this=0x150bc70, uNodeDir=@0x7fffefff7038: 4294967296, 
    uRootIndex=..., uLedgerIndex=..., fDescriber=...)
    at src/cpp/ripple/LedgerEntrySet.cpp:532
#6  0x0000000000e39460 in OfferCreateTransactor::doApply (this=0x7fffe0004eb0)
    at src/cpp/ripple/OfferCreateTransactor.cpp:434
#7  0x0000000000e35540 in Transactor::apply (this=0x7fffe0004eb0)
    at src/cpp/ripple/Transactor.cpp:220
#8  0x0000000000cbf0c9 in TransactionEngine::applyTransaction (this=0x150bc68, 
    txn=..., params=(tapNO_CHECK_SIGN | tapOPEN_LEDGER), 
    didApply=@0x7fffefffbd0b: false) at src/cpp/ripple/TransactionEngine.cpp:107
#9  0x0000000000c155ff in LedgerMaster::doTransaction (this=0x150bc40, txn=..., 
    params=(tapNO_CHECK_SIGN | tapOPEN_LEDGER))
    at src/cpp/ripple/LedgerMaster.cpp:123
#10 0x0000000000c7e067 in NetworkOPs::processTransaction(boost::shared_ptr<Transaction>, boost::function<void (boost::shared_ptr<Transaction>, TER)>) (
    this=0x150c060, trans=..., callback=...)
    at src/cpp/ripple/NetworkOPs.cpp:305
#11 0x0000000000c8a362 in NetworkOPs::processTransaction (this=0x150c060, 
    transaction=...) at src/cpp/ripple/NetworkOPs.h:168
#12 0x0000000000c7cfc2 in NetworkOPs::submitTransactionSync (this=0x150c060, 
    tpTrans=...) at src/cpp/ripple/NetworkOPs.cpp:182
#13 0x0000000000b9caac in RPCHandler::doSubmit (this=0x7fffefffe560, 
    jvRequest=...) at src/cpp/ripple/RPCHandler.cpp:1135
#14 0x0000000000ba61bb in RPCHandler::doCommand (this=0x7fffefffe560, 
    jvRequest=..., iRole=2) at src/cpp/ripple/RPCHandler.cpp:2518
#15 0x0000000000e15443 in WSConnection<websocketpp::endpoint<websocketpp::role::server, websocketpp::socket::plain, websocketpp::log::logger> >::invokeCommand (
    this=0x7fffc0022c30, jvRequest=...) at src/cpp/ripple/WSConnection.h:85
#16 0x0000000000e126e5 in WSServerHandler<websocketpp::endpoint<websocketpp::role::server, websocketpp::socket::plain, websocketpp::log::logger> >::do_message (
    this=0x7fffc001d370, cpClient=..., mpMessage=...)
    at src/cpp/ripple/WSHandler.h:201
[...]

[JoelKatz]

The LedgerEntrySet code is seeing an existing node deleted and then placed in the cache. That's definitely not legal.

[ahbritto]

Fixed and tested.