tests: init g_txindex earlier, move back to TestingSetup

`g_txindex` was moved to `TestChainSetup` in dash#4855 to aid in
removing some crash mitigations. Since then, we have better sync logic
to such crashes and we can finally move it back to `TestingSetup`, as
`TestingSetup` is meant to be complete environment.

Author: kwvg

src/test/util/setup_common.cpp

@@ -302,10 +302,27 @@ TestingSetup::TestingSetup(const std::string& chainName, const std::vector<const
     if (!m_node.chainman->ActiveChainstate().ActivateBestChain(state)) {
         throw std::runtime_error(strprintf("ActivateBestChain failed. (%s)", state.ToString()));
     }
+
+    g_txindex = std::make_unique<TxIndex>(1 << 20, true);
+    if (!g_txindex->Start(m_node.chainman->ActiveChainstate())) {
+        throw std::runtime_error("TxIndex::Start() failed.");
+    }
+
+    // Allow tx index to catch up with the block index.
+    IndexWaitSynced(*g_txindex);
 }
 
 TestingSetup::~TestingSetup()
 {
+    // Allow tx index to catch up with the block index cause otherwise
+    // we might be destroying it while scheduler still has some work for it
+    // e.g. via BlockConnected signal
+    {
+        IndexWaitSynced(*g_txindex);
+        g_txindex->Stop();
+        SyncWithValidationInterfaceQueue();
+        g_txindex.reset();
+    }
     DashTestSetupClose(m_node);
     m_node.connman->Stop();
     m_node.peerman.reset();
@@ -349,14 +366,6 @@ TestChainSetup::TestChainSetup(int num_blocks, const std::vector<const char*>& e
             hash != checkpoints.mapCheckpoints.end() &&
             m_node.chainman->ActiveChain().Tip()->GetBlockHash() == hash->second);
     }
-
-    g_txindex = std::make_unique<TxIndex>(1 << 20, true);
-    if (!g_txindex->Start(m_node.chainman->ActiveChainstate())) {
-        throw std::runtime_error("TxIndex::Start() failed.");
-    }
-
-    // Allow tx index to catch up with the block index.
-    IndexWaitSynced(*g_txindex);
 }
 
 void TestChainSetup::mineBlocks(int num_blocks)
@@ -498,17 +507,6 @@ CMutableTransaction TestChainSetup::CreateValidMempoolTransaction(CTransactionRe
     return mempool_txn;
 }
 
-TestChainSetup::~TestChainSetup()
-{
-    // Allow tx index to catch up with the block index cause otherwise
-    // we might be destroying it while scheduler still has some work for it
-    // e.g. via BlockConnected signal
-    IndexWaitSynced(*g_txindex);
-    g_txindex->Stop();
-    SyncWithValidationInterfaceQueue();
-    g_txindex.reset();
-}
-
 CTxMemPoolEntry TestMemPoolEntryHelper::FromTx(const CMutableTransaction& tx) const
 {
     return FromTx(MakeTransactionRef(tx));

src/test/util/setup_common.h

@@ -122,7 +122,6 @@ class CScript;
 struct TestChainSetup : public RegTestingSetup
 {
     TestChainSetup(int num_blocks, const std::vector<const char*>& extra_args = {});
-    ~TestChainSetup();
 
     /**
      * Create a new block with just given transactions, coinbase paying to