Reproduction test case for a crash described in Bug 330066

New unit test, triggers faulty code in `Screen::copyLineToStream`
which goes outside `Character` array boundaries, overwriting
memory of other objects.
Compiling the code with address-sanitizer makes the fault
visible when running those new UTs.

src/Screen.h

@@ -32,6 +32,7 @@
 
 // Konsole
 #include "Character.h"
+#include "konsoleprivate_export.h"
 
 #define MODE_Origin    0
 #define MODE_Wrap      1
@@ -70,7 +71,7 @@ class HistoryScroll;
     using selectedText().  When getImage() is used to retrieve the visible image,
     characters which are part of the selection have their colors inverted.
 */
-class Screen
+class KONSOLEPRIVATE_EXPORT Screen
 {
 public:
     /* PlainText: Return plain text (default)

src/autotests/CMakeLists.txt

@@ -87,6 +87,12 @@ ecm_mark_nongui_executable(ShellCommandTest)
 add_test(ShellCommandTest ShellCommandTest)
 target_link_libraries(ShellCommandTest ${KONSOLE_TEST_LIBS})
 
+add_executable(ScreenTest ScreenTest.cpp)
+ecm_mark_as_test(ScreenTest)
+ecm_mark_nongui_executable(ScreenTest)
+add_test(ScreenTest ScreenTest)
+target_link_libraries(ScreenTest ${KONSOLE_TEST_LIBS})
+
 add_executable(TerminalCharacterDecoderTest
                TerminalCharacterDecoderTest.cpp)
 ecm_mark_as_test(TerminalCharacterDecoderTest)

src/autotests/ScreenTest.cpp

@@ -0,0 +1,72 @@
+/*
+    Copyright 2020 by Lukasz Kotula <lukasz.kotula@gmx.com>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+    02110-1301  USA.
+*/
+
+// Own
+#include "ScreenTest.h"
+
+// Qt
+#include <QString>
+
+// KDE
+#include <qtest.h>
+
+using namespace Konsole;
+
+void ScreenTest::doLargeScreenCopyVerification(const QString &putToScreen, const QString &expectedSelection)
+{
+  Screen screen(largeScreenLines, largeScreenColumns);
+
+  for(const auto lineCharacter : putToScreen) {
+    screen.displayCharacter(lineCharacter.toLatin1());
+  }
+
+  screen.setSelectionStart(0,0, false);
+  screen.setSelectionEnd(largeScreenColumns,0);
+  QCOMPARE(screen.selectedText(Screen::PlainText), expectedSelection);
+}
+
+void ScreenTest::testLargeScreenCopyShortLine()
+{
+  const QString putToScreen = QStringLiteral("0123456789abcde");
+  const QString expectedSelection = QStringLiteral("0123456789abcde\n");
+  doLargeScreenCopyVerification(putToScreen, expectedSelection);
+}
+
+void ScreenTest::testLargeScreenCopyEmptyLine()
+{
+  const QString putToScreen;
+  const QString expectedSelection = QStringLiteral("\n");
+
+  doLargeScreenCopyVerification(putToScreen, expectedSelection);
+}
+
+void ScreenTest::testLargeScreenCopyLongLine()
+{
+  QString putToScreen;
+
+  // Make the line longer than screen size (1300 characters)
+  for(int i = 0; i <130; ++i) {
+    putToScreen.append(QStringLiteral("0123456789"));
+  }
+  const QString expectedSelection = putToScreen.left(1200);
+
+  doLargeScreenCopyVerification(putToScreen, expectedSelection);
+}
+
+QTEST_GUILESS_MAIN(ScreenTest)

src/autotests/ScreenTest.h

@@ -0,0 +1,50 @@
+/*
+    Copyright 2020 by Lukasz Kotula <lukasz.kotula@gmx.com>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+    02110-1301  USA.
+*/
+
+
+#ifndef SHELLCOMMANDTEST_H
+#define SHELLCOMMANDTEST_H
+
+#include <QObject>
+
+#include "../Screen.h"
+
+namespace Konsole
+{
+
+class ScreenTest : public QObject
+{
+    Q_OBJECT
+
+private Q_SLOTS:
+    void testLargeScreenCopyShortLine();
+    void testLargeScreenCopyEmptyLine();
+    void testLargeScreenCopyLongLine();
+
+private:
+    void doLargeScreenCopyVerification(const QString &putToScreen, const QString &expectedSelection);
+
+    const int largeScreenLines = 10;
+    const int largeScreenColumns = 1200;
+};
+
+}
+
+#endif // SHELLCOMMANDTEST_H
+