Implemented custom close handling

src/DockAreaTabBar.cpp

@@ -478,7 +478,14 @@ void CDockAreaTabBar::onCloseOtherTabsRequested()
 			int Offset = Tab->dockWidget()->features().testFlag(
 				CDockWidget::DockWidgetDeleteOnClose) ? 1 : 0;
 			closeTab(i);
-			i -= Offset;
+
+			// If the the dock widget blocks closing, i.e. if the flag
+			// CustomCloseHandling is set, and the dock widget is still open,
+			// then we do not need to correct the index
+			if (Tab->dockWidget()->isClosed())
+			{
+				i -= Offset;
+			}
 		}
 	}
 }
@@ -569,7 +576,7 @@ void CDockAreaTabBar::closeTab(int Index)
 	{
 		return;
 	}
-	Tab->hide();
+	//Tab->hide();
 	emit tabCloseRequested(Index);
 }