Merge #15308: build: Restore compatibility with older boost

119d360aab travis: Document whether functional tests are run in the job name (Ben Woosley)
64f28545e3 Revert "travis: Compile trusty with depends for now" (Ben Woosley)
267eac00f9 Prefer boost::optional#get_value_or over #value_or (Ben Woosley)
1971f5ba04 Piecewise construct to avoid invalid construction (Ben Woosley)

Pull request description:

  In light of #14979, I realized that only qt 5.5+ was being tested under CI, while compatibility lists 5.2+.

  In #15276, Marco added Trusty to CI, building with depends. This changes that build to system libraries, in order to ensure ongoing compatibility with our claimed minimum required versions.

  Fixes #14983, previously open as #14998

Tree-SHA512: 6cff5e28c756ecb8bf797c8f6eb77c1944ba61a8dd6d7d4984e63eef384f6429dc79c505da3241c05b9c4db31c72b2a9846c7365aba9280f2e0620e5f3998d07

5 files changed, 14 insertions, 9 deletions

diff --git a/.travis.yml b/.travis.yml
index 8bfe39ed8f..99b20dd0d9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -100,11 +100,12 @@ jobs:
         BITCOIN_CONFIG="--enable-zmq --with-gui=qt5 --enable-fuzz --enable-glibc-back-compat --enable-reduce-exports --enable-debug CXXFLAGS=\"-g0 -O2\""
 
     - stage: test
-      name: 'x86_64 Linux  [GOAL: install]  [trusty]  [depends for now]'
+      name: 'x86_64 Linux  [GOAL: install]  [trusty]  [no functional tests, no depends, only system libs]'
       env: >-
         HOST=x86_64-unknown-linux-gnu
         DOCKER_NAME_TAG=ubuntu:14.04
         PACKAGES="python3-zmq qtbase5-dev qttools5-dev-tools libicu-dev libpng-dev libssl-dev libevent-dev bsdmainutils libboost-system-dev libboost-filesystem-dev libboost-chrono-dev libboost-test-dev libboost-thread-dev libdb5.1++-dev libminiupnpc-dev libzmq3-dev libprotobuf-dev protobuf-compiler libqrencode-dev"
+        NO_DEPENDS=1
         RUN_FUNCTIONAL_TESTS=false
         GOAL="install"
         BITCOIN_CONFIG="--enable-zmq --with-incompatible-bdb --with-gui=no"
@@ -139,7 +140,7 @@ jobs:
         BITCOIN_CONFIG="--enable-glibc-back-compat --enable-reduce-exports"
 
     - stage: test
-      name: 'macOS 10.10  [GOAL: deploy]'
+      name: 'macOS 10.10  [GOAL: deploy] [no functional tests]'
       env: >-
         HOST=x86_64-apple-darwin14
         PACKAGES="cmake imagemagick libcap-dev librsvg2-bin libz-dev libbz2-dev libtiff-tools python-dev python3-setuptools-git"
diff --git a/src/interfaces/wallet.cpp b/src/interfaces/wallet.cpp
index 62ede0a95a..a2cae2a7a7 100644
--- a/src/interfaces/wallet.cpp
+++ b/src/interfaces/wallet.cpp
@@ -353,7 +353,7 @@ public:
         LOCK(m_wallet.cs_wallet);
         auto mi = m_wallet.mapWallet.find(txid);
         if (mi != m_wallet.mapWallet.end()) {
-            num_blocks = locked_chain->getHeight().value_or(-1);
+            num_blocks = locked_chain->getHeight().get_value_or(-1);
             in_mempool = mi->second.InMempool();
             order_form = mi->second.vOrderForm;
             tx_status = MakeWalletTxStatus(*locked_chain, mi->second);
@@ -384,7 +384,7 @@ public:
             return false;
         }
         balances = getBalances();
-        num_blocks = locked_chain->getHeight().value_or(-1);
+        num_blocks = locked_chain->getHeight().get_value_or(-1);
         return true;
     }
     CAmount getBalance() override { return m_wallet.GetBalance(); }
diff --git a/src/validationinterface.cpp b/src/validationinterface.cpp
index 533d412888..2e13bef19e 100644
--- a/src/validationinterface.cpp
+++ b/src/validationinterface.cpp
@@ -14,6 +14,7 @@
 #include <list>
 #include <atomic>
 #include <future>
+#include <utility>
 
 #include <boost/signals2/signal.hpp>
 
@@ -77,7 +78,10 @@ size_t CMainSignals::CallbacksPending() {
 }
 
 void CMainSignals::RegisterWithMempoolSignals(CTxMemPool& pool) {
-    g_connNotifyEntryRemoved.emplace(&pool, pool.NotifyEntryRemoved.connect(std::bind(&CMainSignals::MempoolEntryRemoved, this, std::placeholders::_1, std::placeholders::_2)));
+    g_connNotifyEntryRemoved.emplace(std::piecewise_construct,
+        std::forward_as_tuple(&pool),
+        std::forward_as_tuple(pool.NotifyEntryRemoved.connect(std::bind(&CMainSignals::MempoolEntryRemoved, this, std::placeholders::_1, std::placeholders::_2)))
+    );
 }
 
 void CMainSignals::UnregisterWithMempoolSignals(CTxMemPool& pool) {
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 0da2dda092..32c36ceaeb 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -814,7 +814,7 @@ UniValue dumpwallet(const JSONRPCRequest& request)
     file << strprintf("# Wallet dump created by Bitcoin %s\n", CLIENT_BUILD);
     file << strprintf("# * Created on %s\n", FormatISO8601DateTime(GetTime()));
     const Optional<int> tip_height = locked_chain->getHeight();
-    file << strprintf("# * Best block at time of backup was %i (%s),\n", tip_height.value_or(-1), tip_height ? locked_chain->getBlockHash(*tip_height).ToString() : "(missing block hash)");
+    file << strprintf("# * Best block at time of backup was %i (%s),\n", tip_height.get_value_or(-1), tip_height ? locked_chain->getBlockHash(*tip_height).ToString() : "(missing block hash)");
     file << strprintf("#   mined on %s\n", tip_height ? FormatISO8601DateTime(locked_chain->getBlockTime(*tip_height)) : "(missing block time)");
     file << "\n";
 
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 3ce8371abb..9b643be69a 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1720,10 +1720,10 @@ CWallet::ScanResult CWallet::ScanForWalletTransactions(const uint256& start_bloc
         }
         ShowProgress(strprintf("%s " + _("Rescanning..."), GetDisplayName()), 100); // hide progress dialog in GUI
         if (block_height && fAbortRescan) {
-            WalletLogPrintf("Rescan aborted at block %d. Progress=%f\n", block_height.value_or(0), progress_current);
+            WalletLogPrintf("Rescan aborted at block %d. Progress=%f\n", block_height.get_value_or(0), progress_current);
             result.status = ScanResult::USER_ABORT;
         } else if (block_height && ShutdownRequested()) {
-            WalletLogPrintf("Rescan interrupted by shutdown request at block %d. Progress=%f\n", block_height.value_or(0), progress_current);
+            WalletLogPrintf("Rescan interrupted by shutdown request at block %d. Progress=%f\n", block_height.get_value_or(0), progress_current);
             result.status = ScanResult::USER_ABORT;
         }
     }
@@ -2584,7 +2584,7 @@ static bool IsCurrentForAntiFeeSniping(interfaces::Chain::Lock& locked_chain)
  */
 static uint32_t GetLocktimeForNewTransaction(interfaces::Chain::Lock& locked_chain)
 {
-    uint32_t const height = locked_chain.getHeight().value_or(-1);
+    uint32_t const height = locked_chain.getHeight().get_value_or(-1);
     uint32_t locktime;
     // Discourage fee sniping.
     //