CMake: Make server-mode handle server restarts

Make ServerModeReader::parse handle the forceCMakeRun flag gracefully.

The problem there was two-fold:
1. The server would send a "isReadyNow" signal when its connection is
   estabilshed. This made the ServerModeReader trigger another parse run
   with the same parameters.

   That would in turn would force a new ServerMode process to be created.

2. The "configure" request that is sent races the new ServerMode
   process being connected.

Solve both issues by connecting a slot to the server-mode's
connected signal and have that do the right thing.

Change-Id: I26f9ac00d6ad6397a1fd1fab78610951f535ab53
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/cmakeprojectmanager/servermodereader.cpp

@@ -148,8 +148,12 @@ void ServerModeReader::parse(bool forceCMakeRun, bool forceConfiguration)
 
     QTC_ASSERT(m_cmakeServer, return);
     QVariantMap extra;
-    if (forceCMakeRun)
+
+    bool delayConfigurationRun = false;
+    if (forceCMakeRun && m_cmakeServer->isConnected()) {
         createNewServer();
+        delayConfigurationRun = true;
+    }
 
     if (forceConfiguration) {
         QStringList cacheArguments = transform(m_parameters.configuration,
@@ -173,8 +177,11 @@ void ServerModeReader::parse(bool forceCMakeRun, bool forceConfiguration)
                                    tr("Configuring \"%1\"").arg(m_parameters.projectName),
                                    "CMake.Configure");
 
-    m_delayedErrorMessage.clear();
+    if (!delayConfigurationRun) {
-    m_cmakeServer->sendRequest(CONFIGURE_TYPE, extra);
+        sendConfigureRequest(extra);
+    } else {
+        m_delayedConfigurationData = extra;
+    }
 }
 
 void ServerModeReader::stop()
@@ -367,8 +374,11 @@ void ServerModeReader::createNewServer()
     });
     connect(m_cmakeServer.get(), &ServerMode::message,
             this, [](const QString &m) { Core::MessageManager::write(m); });
-    connect(m_cmakeServer.get(), &ServerMode::connected,
+    connect(m_cmakeServer.get(),
-            this, &ServerModeReader::isReadyNow, Qt::QueuedConnection); // Delay
+            &ServerMode::connected,
+            this,
+            &ServerModeReader::handleServerConnected,
+            Qt::QueuedConnection); // Delay
     connect(m_cmakeServer.get(), &ServerMode::disconnected,
             this, [this]() {
         stop();
@@ -461,6 +471,22 @@ void ServerModeReader::handleSignal(const QString &signal, const QVariantMap &da
         emit dirty();
 }
 
+void ServerModeReader::handleServerConnected()
+{
+    if (m_delayedConfigurationData) {
+        sendConfigureRequest(*m_delayedConfigurationData);
+        m_delayedConfigurationData.reset();
+    } else {
+        emit isReadyNow();
+    }
+}
+
+void ServerModeReader::sendConfigureRequest(const QVariantMap &extra)
+{
+    m_delayedErrorMessage.clear();
+    m_cmakeServer->sendRequest(CONFIGURE_TYPE, extra);
+}
+
 void ServerModeReader::reportError()
 {
     stop();

src/plugins/cmakeprojectmanager/servermodereader.h

@@ -67,6 +67,9 @@ private:
     void handleError(const QString &message);
     void handleProgress(int min, int cur, int max, const QString &inReplyTo);
     void handleSignal(const QString &signal, const QVariantMap &data);
+    void handleServerConnected();
+
+    void sendConfigureRequest(const QVariantMap &extra);
 
     void reportError();
 
@@ -163,6 +166,8 @@ private:
     int m_progressStepMinimum = 0;
     int m_progressStepMaximum = 1000;
 
+    Utils::optional<QVariantMap> m_delayedConfigurationData;
+
     QString m_delayedErrorMessage;
 
     CMakeConfig m_cmakeConfiguration;