Consider already selected bundles and allow optional to be wiped out

Currently we only filter bundles by our own closure, but if the closure
transitively pull in more than junit we can still get things from the
target state as there is no alternative.

This now adds all selected bundles to the state to make sure we do not
miss anything that is already selected. Also we allow optional to be
wiped out completely if not from target state.

Author: laeubi

ui/org.eclipse.pde.launching/src/org/eclipse/pde/internal/launching/JUnitLaunchRequirements.java

@@ -46,6 +46,8 @@
 import org.osgi.framework.wiring.BundleCapability;
 import org.osgi.framework.wiring.BundleRequirement;
 import org.osgi.framework.wiring.BundleRevision;
+import org.osgi.resource.Namespace;
+import org.osgi.resource.Requirement;
 
 public class JUnitLaunchRequirements {
 
@@ -56,16 +58,16 @@ public class JUnitLaunchRequirements {
 
 	public static void addRequiredJunitRuntimePlugins(ILaunchConfiguration configuration, Map<String, List<IPluginModelBase>> collectedModels, Map<IPluginModelBase, String> startLevelMap) throws CoreException {
 		Collection<IPluginModelBase> runtimeBundles = getEclipseJunitRuntimePlugins(configuration, collectedModels, startLevelMap);
-		List<BundleDescription> roots = runtimeBundles.stream().map(p -> p.getBundleDescription()).filter(Objects::nonNull).toList();
-		Set<BundleDescription> closure = DependencyManager.findRequirementsClosure(roots);
-		Collection<BundleDescription> runtimeRequirements = filterRequirementsByState(closure, runtimeBundles, configuration);
+		List<BundleDescription> roots = modelsAsDescriptions(runtimeBundles).toList();
+		List<BundleDescription> bundles = Stream.concat(DependencyManager.findRequirementsClosure(roots).stream(), collectedModels.values().stream().flatMap(pl -> modelsAsDescriptions(pl))).distinct().toList();
+		Collection<BundleDescription> runtimeRequirements = filterRequirementsByState(bundles, runtimeBundles, configuration);
 		addAbsentRequirements(runtimeRequirements, collectedModels, startLevelMap);
 	}
 
 	private static Collection<BundleDescription> filterRequirementsByState(Collection<BundleDescription> bundles, Collection<IPluginModelBase> rootBundles, ILaunchConfiguration configuration) throws CoreException {
 		//lookup that maps a copy to the original description from the bundles parameter
 		Map<BundleRevision, BundleDescription> descriptionnMap = new IdentityHashMap<>();
-		Set<BundleRevision> rootSet = rootBundles.stream().map(p -> p.getBundleDescription()).filter(Objects::nonNull).collect(Collectors.toSet());
+		Set<BundleRevision> rootSet = modelsAsDescriptions(rootBundles).collect(Collectors.toSet());
 		State state = FACTORY.createState(true);
 		State targetState = PDECore.getDefault().getModelManager().getState().getState();
 		List<BundleDescription> resolveRoots = new ArrayList<>();
@@ -95,13 +97,18 @@ public void filterResolvable(Collection<BundleRevision> candidates) {
 
 					@Override
 					public void filterMatches(BundleRequirement requirement, Collection<BundleCapability> candidates) {
+						boolean optional = isOptional(requirement);
+						if (candidates.size() == 1 && !optional) {
+							//We only have one candidate and requirement is not optional, so keep it or we get an error!
+							return;
+						}
 						List<BundleCapability> list = candidates.stream().filter(cp -> isFromDifferentState(cp)).toList();
 						if (list.isEmpty()) {
 							//nothing to do here...
 							return;
 						}
 						//iterate in reverse order so we remove lower ranked candidates first ...
-						for (int i = list.size() - 1; i >= 0 && candidates.size() > 1; i--) {
+						for (int i = list.size() - 1; i >= 0 && (optional || candidates.size() > 1); i--) {
 							BundleCapability capability = list.get(i);
 							candidates.remove(capability);
 						}
@@ -129,6 +136,7 @@ public void end() {
 				throw new CoreException(Status.error(String.format("%s can not be resolved: %s", rootBundle, Arrays.toString(errors)))); //$NON-NLS-1$
 			}
 		}
+
 		Collection<BundleDescription> closure = DependencyManager.findRequirementsClosure(resolveRoots);
 		// map back to the originals!
 		return closure.stream().map(bd -> descriptionnMap.get(bd)).filter(Objects::nonNull).toList();
@@ -195,4 +203,13 @@ private static IPluginModelBase findRequiredPluginInTargetOrHost(IPluginModelBas
 		return model;
 	}
 
+	private static Stream<BundleDescription> modelsAsDescriptions(Collection<IPluginModelBase> runtimeBundles) {
+		return runtimeBundles.stream().map(p -> p.getBundleDescription()).filter(Objects::nonNull);
+	}
+
+	private static boolean isOptional(Requirement req) {
+		String resolution = req.getDirectives().get(Namespace.REQUIREMENT_RESOLUTION_DIRECTIVE);
+		return Namespace.RESOLUTION_OPTIONAL.equalsIgnoreCase(resolution);
+	}
+
 }