Valgrind issues in FeatherPad::TabBar and FeatherPad::TextEdit::event

[cepamoi]

Hi,

I ran Valgrind on FeatherPad 1.3.3. And Valgrind reports the two following issues:

==28181== Conditional jump or move depends on uninitialised value(s)
==28181==    at 0x515399: FeatherPad::TabBar::event(QEvent*) (tabbar.cpp:154)
==28181==    by 0x598F6DE: QApplicationPrivate::notify_helper(QObject*, QEvent*) (in /slowfs/vgcertitude2/julient/tools/centos7_64_QSC-S/Qt-5.15.2-64-opensource/lib/libQt5Widgets.so.5.15.2)
==28181==    by 0x5997EB7: QApplication::notify(QObject*, QEvent*) (in /slowfs/vgcertitude2/julient/tools/centos7_64_QSC-S/Qt-5.15.2-64-opensource/lib/libQt5Widgets.so.5.15.2)
==28181==    by 0x6840129: QCoreApplication::notifyInternal2(QObject*, QEvent*) (in /slowfs/vgcertitude2/julient/tools/centos7_64_QSC-S/Qt-5.15.2-64-opensource/lib/libQt5Core.so.5.15.2)
==28181==    by 0x59C0F38: QWidget::setAttribute(Qt::WidgetAttribute, bool) (in /slowfs/vgcertitude2/julient/tools/centos7_64_QSC-S/Qt-5.15.2-64-opensource/lib/libQt5Widgets.so.5.15.2)
==28181==    by 0x511177: QWidget::setMouseTracking(bool) (qwidget.h:824)
==28181==    by 0x514B78: FeatherPad::TabBar::TabBar(QWidget*) (tabbar.cpp:34)
==28181==    by 0x4FAC81: FeatherPad::TabWidget::TabWidget(QWidget*) (tabwidget.cpp:26)
==28181==    by 0x4D961E: FeatherPad::Ui_FPwin::setupUi(QMainWindow*) (ui_fp.h:382)
==28181==    by 0x4928D0: FeatherPad::FPwin::FPwin(QWidget*) (fpwin.cpp:69)
==28181==    by 0x48F382: FeatherPad::FPsingleton::newWin(QStringList const&, int, int) (singleton.cpp:273)
==28181==    by 0x48F2DB: FeatherPad::FPsingleton::firstWin(QStringList const&) (singleton.cpp:266)
==28181== 
==28181== Conditional jump or move depends on uninitialised value(s)
==28181==    at 0x50A52D: FeatherPad::TextEdit::event(QEvent*) (textedit.cpp:2248)
==28181==    by 0x598F6DE: QApplicationPrivate::notify_helper(QObject*, QEvent*) (in /slowfs/vgcertitude2/julient/tools/centos7_64_QSC-S/Qt-5.15.2-64-opensource/lib/libQt5Widgets.so.5.15.2)
==28181==    by 0x5997EB7: QApplication::notify(QObject*, QEvent*) (in /slowfs/vgcertitude2/julient/tools/centos7_64_QSC-S/Qt-5.15.2-64-opensource/lib/libQt5Widgets.so.5.15.2)
==28181==    by 0x6840129: QCoreApplication::notifyInternal2(QObject*, QEvent*) (in /slowfs/vgcertitude2/julient/tools/centos7_64_QSC-S/Qt-5.15.2-64-opensource/lib/libQt5Core.so.5.15.2)
==28181==    by 0x59C0F38: QWidget::setAttribute(Qt::WidgetAttribute, bool) (in /slowfs/vgcertitude2/julient/tools/centos7_64_QSC-S/Qt-5.15.2-64-opensource/lib/libQt5Widgets.so.5.15.2)
==28181==    by 0x511177: QWidget::setMouseTracking(bool) (qwidget.h:824)
==28181==    by 0x4FC54A: FeatherPad::TextEdit::TextEdit(QWidget*, int) (textedit.cpp:63)
==28181==    by 0x54B1ED: FeatherPad::TabPage::TabPage(int, QList<QKeySequence> const&, QWidget*) (tabpage.cpp:30)
==28181==    by 0x4A3C4D: FeatherPad::FPwin::createEmptyTab(bool, bool) (fpwin.cpp:1536)
==28181==    by 0x4A3A24: FeatherPad::FPwin::newTab() (fpwin.cpp:1524)
==28181==    by 0x493991: FeatherPad::FPwin::FPwin(QWidget*) (fpwin.cpp:165)
==28181==    by 0x48F382: FeatherPad::FPsingleton::newWin(QStringList const&, int, int) (singleton.cpp:273)
==28181== 

Calling setMouseTracking(true) in the constructors of the TabBar and TextEdit classes triggers an event.
Thus, the TabBar::event() and TextEdit::event() functions are called.
These functions checks the member variables noTabDND_ and highlighter_ (if (!noTabDND_ ... and if (highlighter_... ).
But these variables have not yet been initialized. Hence the Valgrind errors.

To fix these issues, the member variables noTabDND_ and highlighter_ should be initialized BEFORE the calls to setMouseTracking(true) in the constructors of the TabBar and TextEdit classes.

[tsujan]

Thank you very much for your detailed comment!

Although I've seen no issue in practice, those Valgrind warnings are very important. I'll do as you explained.

[tsujan]

Done in 97b54f0

[cepamoi]

You're welcome!