fix(terminal): free the scroll bar and foreground process info of a closed session

qmltermwidget/lib/Session.cpp

@@ -630,6 +630,7 @@ Session::~Session()
     close();
     delete _emulation;
     delete _shellProcess;
+    delete _foregroundProcessInfo;
 //  delete _zmodemProc;
 }
 

qmltermwidget/lib/TerminalDisplay.cpp

@@ -448,7 +448,7 @@ TerminalDisplay::TerminalDisplay(QQuickItem *parent)
 
   // create scroll bar for scrolling output up and down
   // set the scroll bar's slider to occupy the whole area of the scroll bar initially
-  _scrollBar = new ScrollBar();
+  _scrollBar = new ScrollBar(this);
   // since the contrast with the terminal background may not be enough,
   // the scrollbar should be auto-filled if not transient
   if (!_scrollBar->isTransient())

tests/terminalscroller_test.cpp

@@ -1,3 +1,4 @@
+#include <QPointer>
 #include <QQuickWindow>
 #include <QTest>
 #include <QWheelEvent>
@@ -145,6 +146,17 @@ private slots:
         QVERIFY(value() > 0);
     }
 
+    // Every closed tab destroys a display; its scroll bar goes with it.
+    void closingTheDisplayFreesItsScrollBar()
+    {
+        const QPointer<ScrollBar> scrollBar = m_display->findChild<ScrollBar *>();
+        QVERIFY(scrollBar);
+
+        delete m_display;
+        m_display = nullptr;
+        QVERIFY(scrollBar.isNull());
+    }
+
 private:
     int value() const { return m_display->property("scrollbarCurrentValue").toInt(); }
     int maximum() const { return m_display->property("scrollbarMaximum").toInt(); }