Merge bitcoin-core/gui#123: rpc: Do not accept command while executing another one

38eb37c0bd29b4cb825de905e8eec87636a5221b qt, rpc: Do not accept command while executing another one (Hennadii Stepanov)
0c32b9c5273a4933bda90aa9eb9b7eace6dcaa14 qt, rpc: Accept stop RPC even another command is executing (Hennadii Stepanov)
ccf790287c53edbc7b18983e07f520823436c003 qt, rpc, refactor: Return early in RPCConsole::on_lineEdit_returnPressed (Hennadii Stepanov)
5b9c8c9cdd8e12d2e477840df9d6ab809a613c12 qt, rpc: Add "Executing…" message (Hennadii Stepanov)

Pull request description:

  On master (3f512f3d563954547061ee743648b57a900cbe04) it is possible to enter another command while the current command is still being executed. That makes a mess in the output.

  With this PR:
  ![Screenshot from 2020-10-29 20-48-55](https://user-images.githubusercontent.com/32963518/97619690-329c0880-1a29-11eb-9f5b-6ae3c02c13b2.png)

  Some previous context: https://github.com/bitcoin-core/gui/pull/59#issuecomment-715275185

  ---

  It is still possible to enter and execute the `stop` command any time.

ACKs for top commit:
  jarolrod:
    ACK  38eb37c
  promag:
    Tested ACK 38eb37c0bd29b4cb825de905e8eec87636a5221b.

Tree-SHA512: 2b37a4b6838bf586b1b5c878192106721f713caeb6252514a6540356aab898986396e0777e73891d331b1be797a4926c20d3f9f38ba2c984ea90d55b0c34f664

src/qt/rpcconsole.cpp

@@ -1080,10 +1080,12 @@ void RPCConsole::showPage(int index)
 
 void RPCConsole::on_lineEdit_returnPressed()
 {
-    QString cmd = ui->lineEdit->text();
+    QString cmd = ui->lineEdit->text().trimmed();
+
+    if (cmd.isEmpty()) {
+        return;
+    }
 
-    if(!cmd.isEmpty())
-    {
     std::string strFilteredCmd;
     try {
         std::string dummy;
@@ -1096,9 +1098,18 @@ void RPCConsole::on_lineEdit_returnPressed()
         return;
     }
 
-        ui->lineEdit->clear();
+    // A special case allows to request shutdown even a long-running command is executed.
+    if (cmd == QLatin1String("stop")) {
+        std::string dummy;
+        RPCExecuteCommandLine(m_node, dummy, cmd.toStdString());
+        return;
+    }
 
-        cmdBeforeBrowsing = QString();
+    if (m_is_executing) {
+        return;
+    }
+
+    ui->lineEdit->clear();
 
 #ifdef ENABLE_WALLET
     WalletModel* wallet_model = ui->WalletSelector->currentData().value<WalletModel*>();
@@ -1111,9 +1122,12 @@ void RPCConsole::on_lineEdit_returnPressed()
         }
         m_last_wallet_model = wallet_model;
     }
-#endif
+#endif // ENABLE_WALLET
 
     message(CMD_REQUEST, QString::fromStdString(strFilteredCmd));
+    //: A console message indicating an entered command is currently being executed.
+    message(CMD_REPLY, tr("Executing…"));
+    m_is_executing = true;
     Q_EMIT cmdRequest(cmd, m_last_wallet_model);
 
     cmd = QString::fromStdString(strFilteredCmd);
@@ -1123,15 +1137,15 @@ void RPCConsole::on_lineEdit_returnPressed()
     // Append command to history
     history.append(cmd);
     // Enforce maximum history size
-        while(history.size() > CONSOLE_HISTORY)
+    while (history.size() > CONSOLE_HISTORY) {
         history.removeFirst();
+    }
     // Set pointer to end of history
     historyPtr = history.size();
 
     // Scroll console view to end
     scrollToEnd();
 }
-}
 
 void RPCConsole::browseHistory(int offset)
 {
@@ -1160,7 +1174,13 @@ void RPCConsole::startExecutor()
     executor->moveToThread(&thread);
 
     // Replies from executor object must go to this object
-    connect(executor, &RPCExecutor::reply, this, qOverload<int, const QString&>(&RPCConsole::message));
+    connect(executor, &RPCExecutor::reply, this, [this](int category, const QString& command) {
+        // Remove "Executing…" message.
+        ui->messagesWidget->undo();
+        message(category, command);
+        scrollToEnd();
+        m_is_executing = false;
+    });
 
     // Requests from this object must go to executor
     connect(this, &RPCConsole::cmdRequest, executor, &RPCExecutor::request);

src/qt/rpcconsole.h

@@ -189,6 +189,7 @@ private:
     QCompleter *autoCompleter = nullptr;
     QThread thread;
     WalletModel* m_last_wallet_model{nullptr};
+    bool m_is_executing{false};
 
     /** Update UI with latest network info from model. */
     void updateNetworkState();

src/qt/test/apptests.cpp

@@ -41,7 +41,7 @@ void TestRpcCommand(RPCConsole* console)
     QTest::keyClicks(lineEdit, "getblockchaininfo");
     QTest::keyClick(lineEdit, Qt::Key_Return);
     QVERIFY(mw_spy.wait(1000));
-    QCOMPARE(mw_spy.count(), 2);
+    QCOMPARE(mw_spy.count(), 4);
     QString output = messagesWidget->toPlainText();
     UniValue value;
     value.read(output.right(output.size() - output.indexOf("{")).toStdString());