Bug 262503 - [planner] Replace ResolutionHelper with SAT4J based solutionafter_bug262503

3 files changed, 272 insertions, 60 deletions

diff --git a/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/Projector.java b/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/Projector.java
index 616d604f3..5fabf3aca 100644
--- a/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/Projector.java
+++ b/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/Projector.java
@@ -56,6 +56,8 @@ public class Projector {
 
 	private Collection alreadyInstalledIUs;
 	private boolean considerMetaRequirements;
+	private IInstallableUnit entryPoint;
+	private Map fragments = new HashMap();
 
 	static class AbstractVariable {
 		public String toString() {
@@ -126,8 +128,9 @@ public class Projector {
 		this.considerMetaRequirements = considerMetaRequirements;
 	}
 
-	public void encode(IInstallableUnit metaIu, IInstallableUnit[] alreadyExistingRoots, IInstallableUnit[] newRoots, IProgressMonitor monitor) {
+	public void encode(IInstallableUnit entryPointIU, IInstallableUnit[] alreadyExistingRoots, IInstallableUnit[] newRoots, IProgressMonitor monitor) {
 		alreadyInstalledIUs = Arrays.asList(alreadyExistingRoots);
+		this.entryPoint = entryPointIU;
 		try {
 			long start = 0;
 			if (DEBUG) {
@@ -159,15 +162,15 @@ public class Projector {
 					throw new OperationCanceledException();
 				}
 				IInstallableUnit iuToEncode = (IInstallableUnit) iusToEncode.next();
-				if (iuToEncode != metaIu) {
+				if (iuToEncode != entryPointIU) {
 					processIU(iuToEncode, false);
 				}
 			}
 			createConstraintsForSingleton();
 
-			createMustHave(metaIu, alreadyExistingRoots, newRoots);
+			createMustHave(entryPointIU, alreadyExistingRoots, newRoots);
 
-			createOptimizationFunction(metaIu);
+			createOptimizationFunction(entryPointIU);
 			if (DEBUG) {
 				long stop = System.currentTimeMillis();
 				Tracing.debug("Projection complete: " + (stop - start)); //$NON-NLS-1$
@@ -312,6 +315,9 @@ public class Projector {
 		if (!isApplicable(req))
 			return;
 		List matches = getApplicableMatches(req);
+		if (isHostRequirement(iu, req)) {
+			rememberHostMatches(iu, matches);
+		}
 		if (!req.isOptional()) {
 			if (matches.isEmpty()) {
 				missingRequirement(iu, req);
@@ -380,7 +386,7 @@ public class Projector {
 
 	private void expandRequirementsWithPatches(IInstallableUnit iu, Collector applicablePatches, boolean isRootIu) throws ContradictionException {
 		//Unmodified dependencies
-		Map unchangedRequirements = new HashMap(iu.getRequiredCapabilities().length);
+		Map unchangedRequirements = new HashMap(getRequiredCapabilities(iu).length);
 		for (Iterator iterator = applicablePatches.iterator(); iterator.hasNext();) {
 			IInstallableUnitPatch patch = (IInstallableUnitPatch) iterator.next();
 			IRequiredCapability[][] reqs = mergeRequirements(iu, patch);
@@ -413,6 +419,9 @@ public class Projector {
 				if (isApplicable(reqs[i][1])) {
 					IRequiredCapability req = reqs[i][1];
 					List matches = getApplicableMatches(req);
+					if (isHostRequirement(iu, req)) {
+						rememberHostMatches(iu, matches);
+					}
 					if (!req.isOptional()) {
 						if (matches.isEmpty()) {
 							missingRequirement(patch, req);
@@ -443,6 +452,9 @@ public class Projector {
 				if (isApplicable(reqs[i][0])) {
 					IRequiredCapability req = reqs[i][0];
 					List matches = getApplicableMatches(req);
+					if (isHostRequirement(iu, req)) {
+						rememberHostMatches(iu, matches);
+					}
 					if (!req.isOptional()) {
 						if (matches.isEmpty()) {
 							dependencyHelper.implication(new Object[] {iu}).implies(patch).named(new Explanation.HardRequirement(iu, null));
@@ -487,6 +499,9 @@ public class Projector {
 			}
 			IRequiredCapability req = (IRequiredCapability) entry.getKey();
 			List matches = getApplicableMatches(req);
+			if (isHostRequirement(iu, req)) {
+				rememberHostMatches(iu, matches);
+			}
 			if (!req.isOptional()) {
 				if (matches.isEmpty()) {
 					if (requiredPatches.isEmpty()) {
@@ -749,6 +764,8 @@ public class Projector {
 			Object var = i.next();
 			if (var instanceof IInstallableUnit) {
 				IInstallableUnit iu = (IInstallableUnit) var;
+				if (iu == entryPoint)
+					continue;
 				solution.add(iu);
 			}
 		}
@@ -770,16 +787,6 @@ public class Projector {
 		return solution;
 	}
 
-	public Set getExplanationFor(IInstallableUnit iu) {
-		//TODO if the iu is resolved then return null.
-		//TODO if the iu is in an unknown state, then return a special value in the set
-		try {
-			return dependencyHelper.whyNot(iu);
-		} catch (TimeoutException e) {
-			return Collections.EMPTY_SET;
-		}
-	}
-
 	public Set getExplanation(IProgressMonitor monitor) {
 		ExplanationJob job = new ExplanationJob();
 		job.schedule();
@@ -807,4 +814,46 @@ public class Projector {
 		}
 		return job.getExplanationResult();
 	}
+
+	public Map getFragmentAssociation() {
+		Map resolvedFragments = new HashMap(fragments.size());
+		for (Iterator iterator = fragments.entrySet().iterator(); iterator.hasNext();) {
+			Entry fragment = (Entry) iterator.next();
+			if (!dependencyHelper.getBooleanValueFor(fragment.getKey()))
+				continue;
+			Set potentialHosts = (Set) fragment.getValue();
+			List resolvedHost = new ArrayList(potentialHosts.size());
+			for (Iterator iterator2 = potentialHosts.iterator(); iterator2.hasNext();) {
+				Object host = iterator2.next();
+				if (dependencyHelper.getBooleanValueFor(host))
+					resolvedHost.add(host);
+			}
+			if (resolvedHost.size() != 0)
+				resolvedFragments.put(fragment.getKey(), resolvedHost);
+		}
+		return resolvedFragments;
+	}
+	
+		private void rememberHostMatches(IInstallableUnit fragment, List matches) {
+		Set existingMatches = (Set) fragments.get(fragment);
+		if (existingMatches == null) {
+			existingMatches = new HashSet();
+			fragments.put(fragment, existingMatches);
+			existingMatches.addAll(matches);
+		}
+		existingMatches.retainAll(matches);
+	}
+
+	private boolean isHostRequirement(IInstallableUnit iu, IRequiredCapability req) {
+		if (!(iu instanceof IInstallableUnitFragment))
+			return false;
+		IInstallableUnitFragment fragment = (IInstallableUnitFragment) iu;
+		IRequiredCapability[] reqs = fragment.getHost();
+		for (int i = 0; i < reqs.length; i++) {
+			if (req == reqs[i])
+				return true;
+		}
+		return true;
+	}
+	
 }
\ No newline at end of file
diff --git a/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/SimplePlanner.java b/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/SimplePlanner.java
index b2b1814eb..8efd839fd 100644
--- a/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/SimplePlanner.java
+++ b/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/SimplePlanner.java
@@ -343,9 +343,7 @@ public class SimplePlanner implements IPlanner {
 				LogHelper.log(s);
 			s = Status.OK_STATUS;
 
-			Collection newState = projector.extractSolution();
-			newState.remove(updatedPlan[0]);
-			return newState;
+			return projector;
 		} finally {
 			sub.done();
 		}
@@ -355,22 +353,17 @@ public class SimplePlanner implements IPlanner {
 		SubMonitor sub = SubMonitor.convert(monitor, ExpandWork);
 		sub.setTaskName(Messages.Director_Task_Resolving_Dependencies);
 		try {
-			//Get the solution of the initial request
+			//Get the solution for the initial request
 			Object resolutionResult = getSolutionFor(profileChangeRequest, context, sub.newChild(ExpandWork / 2));
 			if (resolutionResult instanceof ProvisioningPlan)
 				return (ProvisioningPlan) resolutionResult;
 
-			//Compute the set of operands based on the solution obtained previously
-			Collection newState = (Collection) resolutionResult;
+			Collection newState = ((Projector) resolutionResult).extractSolution();
 			Collection fullState = new ArrayList();
 			fullState.addAll(newState);
-			ResolutionHelper newStateHelper = new ResolutionHelper(createSelectionContext(profileChangeRequest.getProfileProperties()), null);
-			newState = newStateHelper.attachCUs(newState);
+			newState = ResolutionHelper.attachFragments(newState, ((Projector) resolutionResult).getFragmentAssociation());
 
-			ResolutionHelper oldStateHelper = new ResolutionHelper(createSelectionContext(profileChangeRequest.getProfile().getProperties()), null);
-			Collection oldState = oldStateHelper.attachCUs(profileChangeRequest.getProfile().query(InstallableUnitQuery.ANY, new Collector(), null).toCollection());
-
-			ProvisioningPlan temporaryPlan = generateProvisioningPlan(oldState, newState, profileChangeRequest, null);
+			ProvisioningPlan temporaryPlan = generatePlan((Projector) resolutionResult, newState, profileChangeRequest);
 
 			//Create a plan for installing necessary pieces to complete the installation (e.g touchpoint actions)
 			return createInstallerPlan(profileChangeRequest.getProfile(), profileChangeRequest, fullState, newState, temporaryPlan, context, sub.newChild(ExpandWork / 2));
@@ -472,14 +465,7 @@ public class SimplePlanner implements IPlanner {
 			return new ProvisioningPlan(externalInstallerStatus, initialRequest, new ProvisioningPlan(externalInstallerStatus, agentRequest, null));
 		}
 
-		Collection newState = (Collection) externalInstallerPlan;
-		ResolutionHelper newStateHelper = new ResolutionHelper(createSelectionContext(agentRequest.getProfileProperties()), null);
-		newState = newStateHelper.attachCUs(newState);
-
-		ResolutionHelper oldStateHelper = new ResolutionHelper(createSelectionContext(agentProfile.getProperties()), null);
-		Collection oldState = oldStateHelper.attachCUs(agentRequest.getProfile().query(InstallableUnitQuery.ANY, new Collector(), null).toCollection());
-
-		initialPlan.setInstallerPlan(generateProvisioningPlan(oldState, newState, agentRequest, null));
+		initialPlan.setInstallerPlan(generatePlan((Projector) externalInstallerPlan, null, agentRequest));
 		return initialPlan;
 	}
 
@@ -517,35 +503,57 @@ public class SimplePlanner implements IPlanner {
 			agentRequest.removeInstallableUnits(new IInstallableUnit[] {previousMetaRequirementIU});
 		agentRequest.addInstallableUnits(new IInstallableUnit[] {metaRequirementIU});
 
-		ProvisioningContext agentCtx = initialContext; //TODO I believe that we are passing too much here
+		ProvisioningContext agentCtx = new ProvisioningContext(new URI[0]);
 		ArrayList extraIUs = new ArrayList(unattachedState);
-		extraIUs.addAll(profile.available(InstallableUnitQuery.ANY, new Collector(), new NullProgressMonitor()).toCollection());
 		agentCtx.setExtraIUs(extraIUs);
-		agentCtx.setProperty(INCLUDE_PROFILE_IUS, Boolean.FALSE.toString());
 		Object agentSolution = getSolutionFor(agentRequest, agentCtx, monitor.newChild(3));
 		if (agentSolution instanceof ProvisioningPlan && ((ProvisioningPlan) agentSolution).getStatus().getSeverity() == IStatus.ERROR) {
 			MultiStatus agentStatus = new MultiStatus(DirectorActivator.PI_DIRECTOR, 0, Messages.Planner_actions_and_software_incompatible, null);
 			agentStatus.add(((ProvisioningPlan) agentSolution).getStatus());
 			return new ProvisioningPlan(agentStatus, initialRequest, new ProvisioningPlan(agentStatus, agentRequest, null));
 		}
-		Collection agentState = (Collection) agentSolution;
-		agentState.remove(metaRequirementIU);
-		ResolutionHelper agentStateHelper = new ResolutionHelper(createSelectionContext(initialRequest.getProfileProperties()), null);
-		agentState = agentStateHelper.attachCUs(agentState);
 
-		ResolutionHelper initialStateHelper = new ResolutionHelper(createSelectionContext(initialRequest.getProfile().getProperties()), null);
-		Collection initialState = initialStateHelper.attachCUs(initialRequest.getProfile().query(InstallableUnitQuery.ANY, new Collector(), null).toCollection());
-		ProvisioningPlan agentPlan = generateProvisioningPlan(initialState, agentState, agentRequest, null);
+		//Compute the installer plan. It is the difference between what is currently in the profile and the solution we just computed
+		Collection agentState = ((Projector) agentSolution).extractSolution();
+		agentState.remove(metaRequirementIU); //Remove the fake IU
+		agentState = ResolutionHelper.attachFragments(agentState, ((Projector) agentSolution).getFragmentAssociation());
 
-		ResolutionHelper newStateHelper = new ResolutionHelper(createSelectionContext(initialRequest.getProfileProperties()), null);
-		expectedState = newStateHelper.attachCUs(expectedState);
+		ProvisioningContext NO_REPO_CONTEXT = new ProvisioningContext(new URI[0]);
+		NO_REPO_CONTEXT.setArtifactRepositories(new URI[0]);
+		//...This computes the attachment of what is currently in the profile 
+		Object initialSolution = getSolutionFor(new ProfileChangeRequest(new EverythingOptionalProfile(initialRequest.getProfile())), NO_REPO_CONTEXT, new NullProgressMonitor());
+		if (initialSolution instanceof ProvisioningPlan) {
+			LogHelper.log(new Status(IStatus.ERROR, DirectorActivator.PI_DIRECTOR, "The resolution of the previous state contained in profile " + initialRequest.getProfile().getProfileId() + " version " + initialRequest.getProfile().getTimestamp() + " failed to resolve.")); //$NON-NLS-1$//$NON-NLS-2$//$NON-NLS-3$
+		}
+		Collection initialState = ((Projector) initialSolution).extractSolution();
+		initialState = ResolutionHelper.attachFragments(initialState, ((Projector) initialSolution).getFragmentAssociation());
 
-		ResolutionHelper oldStateHelper = new ResolutionHelper(createSelectionContext(initialRequest.getProfileProperties()), null); //Here we purposefully use the new properties
-		Set iusAfterActionInstall = new HashSet((Collection) agentSolution);
-		iusAfterActionInstall.addAll(initialRequest.getProfile().query(InstallableUnitQuery.ANY, new Collector(), null).toCollection());
-		Collection oldState = oldStateHelper.attachCUs(iusAfterActionInstall);
+		ProvisioningPlan agentPlan = generateProvisioningPlan(initialState, agentState, initialRequest, null);
+
+		//Compute the installation plan. It is the difference between the state after the installer plan has run and the expectedState.
+		return generateProvisioningPlan(agentState, expectedState, initialRequest, agentPlan);
+	}
+
+	//Compute the set of operands based on the solution obtained previously
+	private ProvisioningPlan generatePlan(Projector newSolution, Collection newState, ProfileChangeRequest request) {
+		//Compute the attachment of the new state if not provided
+		if (newState == null) {
+			newState = newSolution.extractSolution();
+			newState = ResolutionHelper.attachFragments(newState, newSolution.getFragmentAssociation());
+		}
+		ProvisioningContext NO_REPO_CONTEXT = new ProvisioningContext(new URI[0]);
+		NO_REPO_CONTEXT.setArtifactRepositories(new URI[0]);
+
+		//Compute the attachment of the previous state
+		Object initialSolution = getSolutionFor(new ProfileChangeRequest(new EverythingOptionalProfile(request.getProfile())), NO_REPO_CONTEXT, new NullProgressMonitor());
+		if (initialSolution instanceof ProvisioningPlan) {
+			LogHelper.log(new Status(IStatus.ERROR, DirectorActivator.PI_DIRECTOR, "The resolution of the previous state contained in profile " + request.getProfile().getProfileId() + " version " + request.getProfile().getTimestamp() + " failed to resolve.")); //$NON-NLS-1$//$NON-NLS-2$//$NON-NLS-3$
+		}
+		Collection initialState = ((Projector) initialSolution).extractSolution();
+		initialState = ResolutionHelper.attachFragments(initialState, ((Projector) initialSolution).getFragmentAssociation());
 
-		return generateProvisioningPlan(oldState, expectedState, initialRequest, agentPlan);
+		//Generate the plan
+		return generateProvisioningPlan(initialState, newState, request, null);
 	}
 
 	private IInstallableUnit getPreviousIUForMetaRequirements(IProfile profile, String iuId, IProgressMonitor monitor) {
@@ -601,17 +609,18 @@ public class SimplePlanner implements IPlanner {
 				profileChangeRequest.setInstallableUnitProfileProperty((IInstallableUnit) object.getKey(), INCLUSION_RULES, PlannerHelper.createStrictInclusionRule((IInstallableUnit) object.getKey()));
 		}
 		//Remove the iu properties associated to the ius removed and the iu properties being removed as well
-		for (Iterator iterator = alreadyInstalled.iterator(); iterator.hasNext();) {
-			IInstallableUnit iu = (IInstallableUnit) iterator.next();
-			for (int i = 0; i < removed.length; i++) {
-				if (iu.equals(removed[i])) {
-					profileChangeRequest.removeInstallableUnitProfileProperty(removed[i], INCLUSION_RULES);
-					iterator.remove();
-					break;
+		if (removed.length != 0) {
+			for (Iterator iterator = alreadyInstalled.iterator(); iterator.hasNext();) {
+				IInstallableUnit iu = (IInstallableUnit) iterator.next();
+				for (int i = 0; i < removed.length; i++) {
+					if (iu.equals(removed[i])) {
+						profileChangeRequest.removeInstallableUnitProfileProperty(removed[i], INCLUSION_RULES);
+						iterator.remove();
+						break;
+					}
 				}
 			}
 		}
-
 		ArrayList gatheredRequirements = new ArrayList();
 
 		//Process all the IUs being added
@@ -700,4 +709,71 @@ public class SimplePlanner implements IPlanner {
 		Collection results = resultsMap.values();
 		return (IInstallableUnit[]) results.toArray(new IInstallableUnit[results.size()]);
 	}
+
+	//helper class to trick the resolver to believe that everything is optional
+	private static class EverythingOptionalProfile implements IProfile {
+		private IProfile profile;
+
+		public EverythingOptionalProfile(IProfile p) {
+			profile = p;
+		}
+
+		public Collector available(Query query, Collector collector, IProgressMonitor monitor) {
+			return profile.available(query, collector, monitor);
+		}
+
+		public Map getInstallableUnitProperties(IInstallableUnit iu) {
+			return profile.getInstallableUnitProperties(iu);
+		}
+
+		public String getInstallableUnitProperty(IInstallableUnit iu, String key) {
+			if (INCLUSION_RULES.equals(key))
+				return PlannerHelper.createOptionalInclusionRule(iu);
+			return profile.getInstallableUnitProperty(iu, key);
+		}
+
+		public Map getLocalProperties() {
+			return profile.getLocalProperties();
+		}
+
+		public String getLocalProperty(String key) {
+			return profile.getLocalProperty(key);
+		}
+
+		public IProfile getParentProfile() {
+			return profile.getParentProfile();
+		}
+
+		public String getProfileId() {
+			return profile.getProfileId();
+		}
+
+		public Map getProperties() {
+			return profile.getProperties();
+		}
+
+		public String getProperty(String key) {
+			return profile.getProperty(key);
+		}
+
+		public String[] getSubProfileIds() {
+			return profile.getSubProfileIds();
+		}
+
+		public long getTimestamp() {
+			return profile.getTimestamp();
+		}
+
+		public boolean hasSubProfiles() {
+			return profile.hasSubProfiles();
+		}
+
+		public boolean isRootProfile() {
+			return profile.isRootProfile();
+		}
+
+		public Collector query(Query query, Collector collector, IProgressMonitor monitor) {
+			return profile.query(query, collector, monitor);
+		}
+	}
 }
diff --git a/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/resolution/ResolutionHelper.java b/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/resolution/ResolutionHelper.java
index 04bca9d51..ff706c6aa 100644
--- a/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/resolution/ResolutionHelper.java
+++ b/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/resolution/ResolutionHelper.java
@@ -11,6 +11,7 @@
 package org.eclipse.equinox.internal.p2.resolution;
 
 import java.util.*;
+import java.util.Map.Entry;
 import org.eclipse.equinox.internal.p2.director.DirectorActivator;
 import org.eclipse.equinox.internal.p2.director.RecommendationDescriptor;
 import org.eclipse.equinox.internal.provisional.p2.core.Version;
@@ -186,6 +187,92 @@ public class ResolutionHelper {
 		return result;
 	}
 
+	public static Collection attachFragments(Collection toAttach, Map fragmentsToIUs) {
+		Map fragmentBindings = new HashMap();
+		//Build a map inverse of the one provided in input (host --> List of fragments)
+		Map iusToFragment = new HashMap(fragmentsToIUs.size());
+		for (Iterator iterator = fragmentsToIUs.entrySet().iterator(); iterator.hasNext();) {
+			Entry mapping = (Entry) iterator.next();
+			IInstallableUnitFragment fragment = (IInstallableUnitFragment) mapping.getKey();
+			List existingMatches = (List) mapping.getValue();
+
+			for (Iterator iterator2 = existingMatches.iterator(); iterator2.hasNext();) {
+				Object host = iterator2.next();
+				List potentialFragments = (List) iusToFragment.get(host);
+				if (potentialFragments == null) {
+					potentialFragments = new ArrayList();
+					iusToFragment.put(host, potentialFragments);
+				}
+				potentialFragments.add(fragment);
+			}
+		}
+
+		for (Iterator iterator = iusToFragment.entrySet().iterator(); iterator.hasNext();) {
+			Entry entry = (Entry) iterator.next();
+			IInstallableUnit hostIU = (IInstallableUnit) entry.getKey();
+			List potentialIUFragments = (List) entry.getValue();
+			ArrayList applicableFragments = new ArrayList();
+			for (Iterator iterator2 = potentialIUFragments.iterator(); iterator2.hasNext();) {
+				IInstallableUnit dependentIU = (IInstallableUnitFragment) iterator2.next();
+				if (hostIU.equals(dependentIU) || !dependentIU.isFragment())
+					continue;
+
+				IInstallableUnitFragment potentialFragment = (IInstallableUnitFragment) dependentIU;
+
+				// Check to make sure the host meets the requirements of the fragment
+				IRequiredCapability reqsFromFragment[] = potentialFragment.getHost();
+				boolean match = true;
+				boolean requirementMatched = false;
+				for (int l = 0; l < reqsFromFragment.length && match == true; l++) {
+					requirementMatched = false;
+					if (hostIU.satisfies(reqsFromFragment[l]))
+						requirementMatched = true;
+					if (requirementMatched == false) {
+						match = false;
+						break;
+					}
+
+				}
+				if (match) {
+					applicableFragments.add(potentialFragment);
+				}
+			}
+
+			IInstallableUnitFragment theFragment = null;
+			int specificityLevel = 0;
+			for (Iterator iterator4 = applicableFragments.iterator(); iterator4.hasNext();) {
+				IInstallableUnitFragment fragment = (IInstallableUnitFragment) iterator4.next();
+				if (fragment.getHost().length > specificityLevel) {
+					theFragment = fragment;
+					specificityLevel = fragment.getHost().length;
+				}
+			}
+			if (theFragment != null)
+				fragmentBindings.put(hostIU, theFragment);
+		}
+		//build the collection of resolved IUs
+		Collection result = new HashSet(toAttach.size());
+		for (Iterator iterator = toAttach.iterator(); iterator.hasNext();) {
+			IInstallableUnit iu = (IInstallableUnit) iterator.next();
+			if (iu == null)
+				continue;
+			//just return fragments as they are
+			if (iu.isFragment()) {
+				result.add(iu);
+				continue;
+			}
+			//return a new IU that combines the IU with its bound fragments
+			IInstallableUnitFragment fragment = (IInstallableUnitFragment) fragmentBindings.get(iu);
+			IInstallableUnitFragment[] fragments;
+			if (fragment == null)
+				fragments = NO_FRAGMENTS;
+			else
+				fragments = new IInstallableUnitFragment[] {fragment};
+			result.add(MetadataFactory.createResolvedInstallableUnit(iu, fragments));
+		}
+		return result;
+	}
+
 	public boolean isResolved(IInstallableUnit iu) {
 		return state.getBundle(iu.getId(), Version.toOSGiVersion(iu.getVersion())).isResolved();
 	}