Bug 331668 ESelectionService should not notify listeners if the active part does not post selections
Even if you do not set a selection provider for your IWorkbenchPart implementation, we are still propagating selection events for that part within the given workbench window.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/SelectionServiceImpl.java
IEclipseContext context = part.getContext();
		if (context != null && tracked.add(context)) {
			context.runAndTrack(new RunAndTrack() {
				private boolean initial = true;
				public boolean changed(IEclipseContext context) {
					if (serviceRoot == null) {
						
						return false;
					}
					Object selection = context.get(OUT_SELECTION);
					if (initial) {
						initial = false;
						if (selection == null) {
							return true;
						}
					}
					if (activePart == part) {
						notifyListeners(part, selection);
					} else {
						notifyTargetedListeners(part, selection);
					}
					return true;
				}
			});
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.e4.ui.selection.ESelectionService#setSelection(java.lang.Object)