Bug 71287 Reuse editor preference has no effect in tree mode
options -> Reuse editors to show matches in workbench -> search - has no effect
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/search/JavaSearchEditorOpener.java
import org.eclipse.jdt.core.IClassFile;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IMember;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.ui.JavaUI;
import org.eclipse.jdt.internal.ui.JavaPlugin;
import org.eclipse.jdt.internal.ui.javaeditor.EditorUtility;
import org.eclipse.jdt.internal.ui.javaeditor.InternalClassFileEditorInput;
public class JavaSearchEditorOpener {
	private IEditorPart fEditor;
	public IEditorPart open(Match match) throws PartInitException, JavaModelException {
		IWorkbenchPage wbPage= JavaPlugin.getActivePage();
		Object element= getElementToOpen(match);
		if (NewSearchUI.reuseEditor())
			return showWithReuse(element, wbPage);
		else
			return showWithoutReuse(element, wbPage);
	}
	protected Object getElementToOpen(Match match) {
		return match.getElement();
	}
	private IEditorPart showWithoutReuse(Object element, IWorkbenchPage wbPage) throws PartInitException, JavaModelException {
		return EditorUtility.openInEditor(element, false);
	}
	private IEditorPart showWithReuse(Object element, IWorkbenchPage wbPage) throws JavaModelException, PartInitException {
		IFile file= getFile(element);
		if (file != null) {
			String editorID= getEditorID(file);
			return showInEditor(wbPage, new FileEditorInput(file), editorID);