DateBarWidget: fix assertion.

BUG: 426538

DateBar/DateBarWidget.cpp

@@ -832,7 +832,7 @@ void DateBar::DateBarWidget::focusOutEvent(QFocusEvent *)
 int DateBar::DateBarWidget::unitAtPos(int x) const
 {
     Q_ASSERT_X(x - barAreaGeometry().left() >= 0, "DateBarWidget::unitAtPos", "horizontal offset cannot be negative!");
-    Q_ASSERT_X(x - barAreaGeometry().left() <= m_barWidth, "DateBarWidget::unitAtPos", "horizontal offset larger than m_barWidth!");
+    Q_ASSERT_X(x - barAreaGeometry().left() <= barAreaGeometry().width(), "DateBarWidget::unitAtPos", "horizontal offset larger than total width!");
     return (x - barAreaGeometry().left()) / m_barWidth;
 }
 

DateBar/DateBarWidget.h

@@ -221,7 +221,7 @@ private:
 
     int m_currentUnit;
     QDateTime m_currentDate;
-    int m_barWidth;
+    int m_barWidth; ///< width of a single unit in pixel
     int m_barHeight;
     bool m_includeFuzzyCounts;
     QMenu *m_contextMenu;