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, 27 insertions, 8 deletions

diff --git a/src/wallet.cpp b/src/wallet.cpp
index daca7ac04b..3d679f4c56 100644
--- a/src/wallet.cpp
+++ b/src/wallet.cpp
@@ -145,6 +145,22 @@ bool CWallet::LoadCScript(const CScript& redeemScript)
     return CCryptoKeyStore::AddCScript(redeemScript);
 }
 
+bool CWallet::AddWatchOnly(const CTxDestination &dest)
+{
+    if (!CCryptoKeyStore::AddWatchOnly(dest))
+        return false;
+    nTimeFirstKey = 1; // No birthday information for watch-only keys.
+    if (!fFileBacked)
+        return true;
+    return CWalletDB(strWalletFile).WriteWatchOnly(dest);
+}
+
+bool CWallet::LoadWatchOnly(const CTxDestination &dest)
+{
+    LogPrintf("Loaded %s!\n", CBitcoinAddress(dest).ToString().c_str());
+    return CCryptoKeyStore::AddWatchOnly(dest);
+}
+
 bool CWallet::Unlock(const SecureString& strWalletPassphrase)
 {
     CCrypter crypter;
@@ -680,7 +696,7 @@ void CWallet::EraseFromWallet(const uint256 &hash)
 }
 
 
-bool CWallet::IsMine(const CTxIn &txin) const
+isminetype CWallet::IsMine(const CTxIn &txin) const
 {
     {
         LOCK(cs_wallet);
@@ -689,11 +705,10 @@ bool CWallet::IsMine(const CTxIn &txin) const
         {
             const CWalletTx& prev = (*mi).second;
             if (txin.prevout.n < prev.vout.size())
-                if (IsMine(prev.vout[txin.prevout.n]))
-                    return true;
+                return IsMine(prev.vout[txin.prevout.n]);
         }
     }
-    return false;
+    return MINE_NO;
 }
 
 int64_t CWallet::GetDebit(const CTxIn &txin) const
@@ -1051,7 +1066,7 @@ int64_t CWallet::GetImmatureBalance() const
     return nTotal;
 }
 
-// populate vCoins with vector of spendable COutputs
+// populate vCoins with vector of available COutputs.
 void CWallet::AvailableCoins(vector<COutput>& vCoins, bool fOnlyConfirmed, const CCoinControl *coinControl) const
 {
     vCoins.clear();
@@ -1077,10 +1092,11 @@ void CWallet::AvailableCoins(vector<COutput>& vCoins, bool fOnlyConfirmed, const
                 continue;
 
             for (unsigned int i = 0; i < pcoin->vout.size(); i++) {
-                if (!(IsSpent(wtxid, i)) && IsMine(pcoin->vout[i]) &&
+                isminetype mine = IsMine(pcoin->vout[i]);
+                if (!(IsSpent(wtxid, i)) && mine != MINE_NO &&
                     !IsLockedCoin((*it).first, i) && pcoin->vout[i].nValue > 0 &&
                     (!coinControl || !coinControl->HasSelected() || coinControl->IsSelected((*it).first, i)))
-                        vCoins.push_back(COutput(pcoin, i, nDepth));
+                        vCoins.push_back(COutput(pcoin, i, nDepth, mine & MINE_SPENDABLE));
             }
         }
     }
@@ -1147,8 +1163,11 @@ bool CWallet::SelectCoinsMinConf(int64_t nTargetValue, int nConfMine, int nConfT
 
     random_shuffle(vCoins.begin(), vCoins.end(), GetRandInt);
 
-    BOOST_FOREACH(COutput output, vCoins)
+    BOOST_FOREACH(const COutput &output, vCoins)
     {
+        if (!output.fSpendable)
+            continue;
+
         const CWalletTx *pcoin = output.tx;
 
         if (output.nDepth < (pcoin->IsFromMe() ? nConfMine : nConfTheirs))