Bug 339573 Splitting the shared area with a part doesn't remove stale placeholders
The current code only looks for the addition of an MPlaceholder in the shared area as the hint to remove locals. When you split the area the element that gets added is the new MPartSashContainer...
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/ModelServiceImpl.java
}
			toolControl.setToBeRendered(false);
			toolControl.getParent().getChildren().remove(toolControl);
		}
	}
	public void removePerspectiveModel(MPerspective persp, MWindow window) {
		
		MUIElement psElement = persp.getParent();
		MPerspectiveStack ps = (MPerspectiveStack) psElement;
		boolean foundNewSelection = false;
		if (ps.getSelectedElement() == persp) {
			for (MPerspective p : ps.getChildren()) {
				if (p != persp && p.isToBeRendered()) {
					ps.setSelectedElement(p);
					foundNewSelection = true;
					break;
				}
			}
			if (!foundNewSelection) {
				ps.setSelectedElement(null);
			}
		}
		
		resetPerspectiveModel(persp, window);
		
		persp.setToBeRendered(false);
		ps.getChildren().remove(persp);
	}
	/*
	 * (non-Javadoc)