[wallet] Remove package limit config access from wallet

The wallet should not be able to directly access global configuration
from the node. Remove access of "-limitancestorcount" and
"-limitdescendantcount".

Author: jnewbery

src/interfaces/chain.cpp

@@ -298,6 +298,11 @@ class ChainImpl : public Chain
     {
         ::mempool.GetTransactionAncestry(txid, ancestors, descendants);
     }
+    void getPackageLimits(unsigned int& limit_ancestor_count, unsigned int& limit_descendant_count) override
+    {
+        limit_ancestor_count = gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT);
+        limit_descendant_count = gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT);
+    }
     bool checkChainLimits(const CTransactionRef& tx) override
     {
         LockPoints lp;

src/interfaces/chain.h

@@ -163,6 +163,11 @@ class Chain
     //! Calculate mempool ancestor and descendant counts for the given transaction.
     virtual void getTransactionAncestry(const uint256& txid, size_t& ancestors, size_t& descendants) = 0;
 
+    //! Get the node's package limits.
+    //! Currently only returns the ancestor and descendant count limits, but could be enhanced to
+    //! return more policy settings.
+    virtual void getPackageLimits(unsigned int& limit_ancestor_count, unsigned int& limit_descendant_count) = 0;
+
     //! Check if transaction will pass the mempool's chain limits.
     virtual bool checkChainLimits(const CTransactionRef& tx) = 0;
 

src/wallet/wallet.cpp

@@ -27,7 +27,6 @@
 #include <util/rbf.h>
 #include <util/translation.h>
 #include <util/validation.h>
-#include <validation.h>
 #include <wallet/coincontrol.h>
 #include <wallet/fees.h>
 
@@ -2739,8 +2738,11 @@ bool CWallet::SelectCoins(const std::vector<COutput>& vAvailableCoins, const CAm
     }
     std::vector<OutputGroup> groups = GroupOutputs(vCoins, !coin_control.m_avoid_partial_spends);
 
-    size_t max_ancestors = (size_t)std::max<int64_t>(1, gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT));
-    size_t max_descendants = (size_t)std::max<int64_t>(1, gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT));
+    unsigned int limit_ancestor_count;
+    unsigned int limit_descendant_count;
+    chain().getPackageLimits(limit_ancestor_count, limit_descendant_count);
+    size_t max_ancestors = (size_t)std::max<int64_t>(1, limit_ancestor_count);
+    size_t max_descendants = (size_t)std::max<int64_t>(1, limit_descendant_count);
     bool fRejectLongChains = gArgs.GetBoolArg("-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS);
 
     bool res = nTargetValue <= nValueFromPresetInputs ||