Add support for watch-only addresses

Changes:
* Add Add/Have WatchOnly methods to CKeyStore, and implementations
  in CBasicKeyStore.
* Add similar methods to CWallet, and support entries for it in
  CWalletDB.
* Make IsMine in script/wallet return a new enum 'isminetype',
  rather than a boolean. This allows distinguishing between
  spendable and unspendable coins.
* Add a field fSpendable to COutput (GetAvailableCoins' return type).
* Mark watchonly coins in listunspent as 'watchonly': true.
* Add 'watchonly' to validateaddress, suppressing script/pubkey/...
  in this case.

Based on a patch by Eric Lombrozo.

Conflicts:
	src/qt/walletmodel.cpp
	src/rpcserver.cpp
	src/wallet.cpp

1 files changed, 31 insertions, 21 deletions

diff --git a/src/rpcmisc.cpp b/src/rpcmisc.cpp
index 5b470516a1..e2de2dbcdb 100644
--- a/src/rpcmisc.cpp
+++ b/src/rpcmisc.cpp
@@ -92,36 +92,45 @@ Value getinfo(const Array& params, bool fHelp)
 #ifdef ENABLE_WALLET
 class DescribeAddressVisitor : public boost::static_visitor<Object>
 {
+private:
+    isminetype mine;
+
 public:
+    DescribeAddressVisitor(isminetype mineIn) : mine(mineIn) {}
+
     Object operator()(const CNoDestination &dest) const { return Object(); }
 
     Object operator()(const CKeyID &keyID) const {
         Object obj;
         CPubKey vchPubKey;
-        pwalletMain->GetPubKey(keyID, vchPubKey);
         obj.push_back(Pair("isscript", false));
-        obj.push_back(Pair("pubkey", HexStr(vchPubKey)));
-        obj.push_back(Pair("iscompressed", vchPubKey.IsCompressed()));
+        if (mine == MINE_SPENDABLE) {
+            pwalletMain->GetPubKey(keyID, vchPubKey);
+            obj.push_back(Pair("pubkey", HexStr(vchPubKey)));
+            obj.push_back(Pair("iscompressed", vchPubKey.IsCompressed()));
+        }
         return obj;
     }
 
     Object operator()(const CScriptID &scriptID) const {
         Object obj;
         obj.push_back(Pair("isscript", true));
-        CScript subscript;
-        pwalletMain->GetCScript(scriptID, subscript);
-        std::vector<CTxDestination> addresses;
-        txnouttype whichType;
-        int nRequired;
-        ExtractDestinations(subscript, whichType, addresses, nRequired);
-        obj.push_back(Pair("script", GetTxnOutputType(whichType)));
-        obj.push_back(Pair("hex", HexStr(subscript.begin(), subscript.end())));
-        Array a;
-        BOOST_FOREACH(const CTxDestination& addr, addresses)
-            a.push_back(CBitcoinAddress(addr).ToString());
-        obj.push_back(Pair("addresses", a));
-        if (whichType == TX_MULTISIG)
-            obj.push_back(Pair("sigsrequired", nRequired));
+        if (mine == MINE_SPENDABLE) {
+            CScript subscript;
+            pwalletMain->GetCScript(scriptID, subscript);
+            std::vector<CTxDestination> addresses;
+            txnouttype whichType;
+            int nRequired;
+            ExtractDestinations(subscript, whichType, addresses, nRequired);
+            obj.push_back(Pair("script", GetTxnOutputType(whichType)));
+            obj.push_back(Pair("hex", HexStr(subscript.begin(), subscript.end())));
+            Array a;
+            BOOST_FOREACH(const CTxDestination& addr, addresses)
+                a.push_back(CBitcoinAddress(addr).ToString());
+            obj.push_back(Pair("addresses", a));
+            if (whichType == TX_MULTISIG)
+                obj.push_back(Pair("sigsrequired", nRequired));
+        }
         return obj;
     }
 };
@@ -161,10 +170,11 @@ Value validateaddress(const Array& params, bool fHelp)
         string currentAddress = address.ToString();
         ret.push_back(Pair("address", currentAddress));
 #ifdef ENABLE_WALLET
-        bool fMine = pwalletMain ? IsMine(*pwalletMain, dest) : false;
-        ret.push_back(Pair("ismine", fMine));
-        if (fMine) {
-            Object detail = boost::apply_visitor(DescribeAddressVisitor(), dest);
+        isminetype mine = pwalletMain ? IsMine(*pwalletMain, dest) : MINE_NO;
+        ret.push_back(Pair("ismine", mine != MINE_NO));
+        if (mine != MINE_NO) {
+            ret.push_back(Pair("watchonly", mine == MINE_WATCH_ONLY));
+            Object detail = boost::apply_visitor(DescribeAddressVisitor(mine), dest);
             ret.insert(ret.end(), detail.begin(), detail.end());
         }
         if (pwalletMain && pwalletMain->mapAddressBook.count(dest))