Merge #10484: 0.14 Backports

1847642 [Wallet] unset change position when there is no change on exact match (Gregory Sanders)
ae479bc build: fix bitcoin-config.h regeneration after touching build files (Cory Fields)
3d395d6 build: remove wonky auto top-level convenience targets (Cory Fields)
4bc99c3 Add missing <atomic> header in clientmodel.h (Jonas Schnelli)
222f377 Set both time/height header caches at the same time (Jonas Schnelli)
7da1337 Declare headers height/time cache mutable, re-set the methods const (Jonas Schnelli)
9ac40e8 Update the remaining blocks left in modaloverlay at init. (Jonas Schnelli)
1e936d7 Reduce cs_main locks during modal overlay by adding an atomic cache (Jonas Schnelli)
0aee4a1 Check interruptNet during dnsseed lookups (Matt Corallo)

6 files changed, 49 insertions, 12 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index e8d22313d..76dbbced6 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -457,6 +457,14 @@ DISTCLEANFILES = obj/build.h
 
 EXTRA_DIST = $(CTAES_DIST)
 
+
+config/bitcoin-config.h: config/stamp-h1
+	@$(MAKE) -C $(top_builddir) $(subdir)/$(@)
+config/stamp-h1: $(top_srcdir)/$(subdir)/config/bitcoin-config.h.in $(top_builddir)/config.status
+	$(AM_V_at)$(MAKE) -C $(top_builddir) $(subdir)/$(@)
+$(top_srcdir)/$(subdir)/config/bitcoin-config.h.in:  $(am__configure_deps)
+	$(AM_V_at)$(MAKE) -C $(top_srcdir) $(subdir)/config/bitcoin-config.h.in
+
 clean-local:
 	-$(MAKE) -C secp256k1 clean
 	-$(MAKE) -C univalue clean
diff --git a/src/net.cpp b/src/net.cpp
index 5593f81ef..2fca99474 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -1579,6 +1579,9 @@ void CConnman::ThreadDNSAddressSeed()
     LogPrintf("Loading addresses from DNS seeds (could take a while)\n");
 
     BOOST_FOREACH(const CDNSSeedData &seed, vSeeds) {
+        if (interruptNet) {
+            return;
+        }
         if (HaveNameProxy()) {
             AddOneShot(seed.host);
         } else {
@@ -1596,6 +1599,9 @@ void CConnman::ThreadDNSAddressSeed()
                     found++;
                 }
             }
+            if (interruptNet) {
+                return;
+            }
             // TODO: The seed name resolve may fail, yielding an IP of [::], which results in
             // addrman assigning the same source to results from different seeds.
             // This should switch to a hard-coded stable dummy IP for each seed name, so that the
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index be79a6799..5c26baef9 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -478,6 +478,7 @@ void BitcoinGUI::setClientModel(ClientModel *_clientModel)
         connect(_clientModel, SIGNAL(numConnectionsChanged(int)), this, SLOT(setNumConnections(int)));
         connect(_clientModel, SIGNAL(networkActiveChanged(bool)), this, SLOT(setNetworkActive(bool)));
 
+        modalOverlay->setKnownBestHeight(_clientModel->getHeaderTipHeight(), QDateTime::fromTime_t(_clientModel->getHeaderTipTime()));
         setNumBlocks(_clientModel->getNumBlocks(), _clientModel->getLastBlockDate(), _clientModel->getVerificationProgress(NULL), false);
         connect(_clientModel, SIGNAL(numBlocksChanged(int,QDateTime,double,bool)), this, SLOT(setNumBlocks(int,QDateTime,double,bool)));
 
@@ -505,8 +506,6 @@ void BitcoinGUI::setClientModel(ClientModel *_clientModel)
             // initialize the disable state of the tray icon with the current value in the model.
             setTrayIconVisible(optionsModel->getHideTrayIcon());
         }
-
-        modalOverlay->setKnownBestHeight(clientModel->getHeaderTipHeight(), QDateTime::fromTime_t(clientModel->getHeaderTipTime()));
     } else {
         // Disable possibility to show main window via action
         toggleHideAction->setEnabled(false);
diff --git a/src/qt/clientmodel.cpp b/src/qt/clientmodel.cpp
index bb10e4942..20d468797 100644
--- a/src/qt/clientmodel.cpp
+++ b/src/qt/clientmodel.cpp
@@ -36,6 +36,8 @@ ClientModel::ClientModel(OptionsModel *_optionsModel, QObject *parent) :
     banTableModel(0),
     pollTimer(0)
 {
+    cachedBestHeaderHeight = -1;
+    cachedBestHeaderTime = -1;
     peerTableModel = new PeerTableModel(this);
     banTableModel = new BanTableModel(this);
     pollTimer = new QTimer(this);
@@ -74,18 +76,28 @@ int ClientModel::getNumBlocks() const
 
 int ClientModel::getHeaderTipHeight() const
 {
-    LOCK(cs_main);
-    if (!pindexBestHeader)
-        return 0;
-    return pindexBestHeader->nHeight;
+    if (cachedBestHeaderHeight == -1) {
+        // make sure we initially populate the cache via a cs_main lock
+        // otherwise we need to wait for a tip update
+        LOCK(cs_main);
+        if (pindexBestHeader) {
+            cachedBestHeaderHeight = pindexBestHeader->nHeight;
+            cachedBestHeaderTime = pindexBestHeader->GetBlockTime();
+        }
+    }
+    return cachedBestHeaderHeight;
 }
 
 int64_t ClientModel::getHeaderTipTime() const
 {
-    LOCK(cs_main);
-    if (!pindexBestHeader)
-        return 0;
-    return pindexBestHeader->GetBlockTime();
+    if (cachedBestHeaderTime == -1) {
+        LOCK(cs_main);
+        if (pindexBestHeader) {
+            cachedBestHeaderHeight = pindexBestHeader->nHeight;
+            cachedBestHeaderTime = pindexBestHeader->GetBlockTime();
+        }
+    }
+    return cachedBestHeaderTime;
 }
 
 quint64 ClientModel::getTotalBytesRecv() const
@@ -283,6 +295,11 @@ static void BlockTipChanged(ClientModel *clientmodel, bool initialSync, const CB
 
     int64_t& nLastUpdateNotification = fHeader ? nLastHeaderTipUpdateNotification : nLastBlockTipUpdateNotification;
 
+    if (fHeader) {
+        // cache best headers time and height to reduce future cs_main locks
+        clientmodel->cachedBestHeaderHeight = pIndex->nHeight;
+        clientmodel->cachedBestHeaderTime = pIndex->GetBlockTime();
+    }
     // if we are in-sync, update the UI regardless of last update time
     if (!initialSync || now - nLastUpdateNotification > MODEL_UPDATE_DELAY) {
         //pass a async signal to the UI thread
diff --git a/src/qt/clientmodel.h b/src/qt/clientmodel.h
index 2c10e633b..4c92e2144 100644
--- a/src/qt/clientmodel.h
+++ b/src/qt/clientmodel.h
@@ -8,6 +8,8 @@
 #include <QObject>
 #include <QDateTime>
 
+#include <atomic>
+
 class AddressTableModel;
 class BanTableModel;
 class OptionsModel;
@@ -81,6 +83,10 @@ public:
     QString formatClientStartupTime() const;
     QString dataDir() const;
 
+    // caches for the best header
+    mutable std::atomic<int> cachedBestHeaderHeight;
+    mutable std::atomic<int64_t> cachedBestHeaderTime;
+
 private:
     OptionsModel *optionsModel;
     PeerTableModel *peerTableModel;
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 1b59c3cd8..3e93a56d5 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2587,9 +2587,10 @@ bool CWallet::CreateTransaction(const vector<CRecipient>& vecSend, CWalletTx& wt
                         vector<CTxOut>::iterator position = txNew.vout.begin()+nChangePosInOut;
                         txNew.vout.insert(position, newTxOut);
                     }
-                }
-                else
+                } else {
                     reservekey.ReturnKey();
+                    nChangePosInOut = -1;
+                }
 
                 // Fill vin
                 //