Bug 293159 [Browser] Search for external browser in Preferences finds > 40 instances of firefox on Ubuntu 64bit, if started in /usr/bin
bundles/org.eclipse.ui.browser/src/org/eclipse/ui/internal/browser/WebBrowserPreferencePage.java
.addSelectionChangedListener(new ISelectionChangedListener() {
					public void selectionChanged(SelectionChangedEvent event) {
						IStructuredSelection sele = ((IStructuredSelection) tableViewer
								.getSelection());
						boolean sel = sele.getFirstElement() != null &&
								!(sele.getFirstElement() instanceof SystemBrowserDescriptor);
						remove.setEnabled(sel);
						edit.setEnabled(sel);
					}
				});
		tableViewer.addDoubleClickListener(new IDoubleClickListener() {
			public void doubleClick(DoubleClickEvent event) {
				IStructuredSelection sel = ((IStructuredSelection) tableViewer
						.getSelection());
				Object firstElem = sel.getFirstElement();
				if (firstElem != null && !(firstElem instanceof SystemBrowserDescriptor)) {
					IBrowserDescriptor browser2 = (IBrowserDescriptor) sel
							.getFirstElement();
					IBrowserDescriptorWorkingCopy wc = browser2
							.getWorkingCopy();
					BrowserDescriptorDialog dialog = new BrowserDescriptorDialog(
							getShell(), wc);
					if (dialog.open() != Window.CANCEL) {
						try {
							tableViewer.refresh(wc.save());
						} catch (Exception ex) {
							
						}
					}
				}