Bug 175742 [Markers] contributed marker resolutions only showing first contribution
Debug is trying to add a marker resolution for a quick fix to repair deprecated JRE variables on the build path. When we contribute our resolution generator for org.eclipse.jdt.core.buildpath_problem marker types with a DEPRECATED_VARIABLE id attribute, we find that our resolution is always over-written by the junit generator. It seems that the MarkerHelpRegistry does not allow more than one generator per query result (in our case DEPRECATED_VARIABLE is the query result, same with junit's contribution). I would expect that you could have more than one quickfix for a given issue (in this case what to do about deprecated build path variables).
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/registry/MarkerHelpRegistry.java
/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.internal.ide.registry;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.eclipse.core.resources.IMarker;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.Platform;
import org.eclipse.ui.IMarkerHelpRegistry;
import org.eclipse.ui.IMarkerResolution;
import org.eclipse.ui.IMarkerResolutionGenerator;
import org.eclipse.ui.IMarkerResolutionGenerator2;