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
import org.eclipse.ui.internal.ide.IDEWorkbenchPlugin;
import org.osgi.framework.Bundle;
/**
 * This class is a registry for marker help
 * contexts and resolutions.
 */
public class MarkerHelpRegistry implements IMarkerHelpRegistry {
    /**
     * Table of queries for marker F1 help.
     */
    private Map helpQueries = new HashMap();
    /**
     * Sorted list of help queries.
     * Used to ensure that the "most specific"
     * query is tried first
     */
    private List sortedHelpQueries;
    /**
     * Table of queries for marker resolutions
     */
    private Map resolutionQueries = new HashMap();
    /**
     * Help context id attribute in configuration element
     */
    private static final String ATT_HELP = "helpContextId"; 
    /**
     * Resolution class attribute name in configuration element
     */
    private static final String ATT_CLASS = "class"; 
    private class QueryComparator implements Comparator {