further fixing of #229: Fix org.objectweb.asm version collision

It appears as if xtext.common.types 2.16.x updated its org.objectweb.asm
dependency to 7.0.0, so if we have both available in an Eclipse install,
we should use the newer version.

de.gebit.integrity.eclipse/src/de/gebit/integrity/eclipse/classpath/IntegrityClasspathContainer.java

@@ -8,7 +8,9 @@
 package de.gebit.integrity.eclipse.classpath;
 
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IStatus;
@@ -135,9 +137,23 @@ private void addToList(List<IClasspathEntry> aList, String[][] someBundleNames)
 	}
 
 	private Bundle findBundle(String aSymbolicName) {
+		return findBundleRecursive(aSymbolicName, FrameworkUtil.getBundle(JavaCore.class), new HashSet<>());
+	}
+
+	private Bundle findBundleRecursive(String aSymbolicName, Bundle aRootBundle, Set<Bundle> someSeenBundles) {
 		Bundle tempBundleMatch = null;
 
-		for (Bundle tempBundleCandidate : FrameworkUtil.getBundle(JavaCore.class).getBundleContext().getBundles()) {
+		if (aRootBundle.getBundleContext() == null) {
+			return null;
+		}
+
+		for (Bundle tempBundleCandidate : aRootBundle.getBundleContext().getBundles()) {
+			if (someSeenBundles.contains(tempBundleCandidate)) {
+				continue;
+			} else {
+				someSeenBundles.add(tempBundleCandidate);
+			}
+
 			if (tempBundleCandidate.getSymbolicName().equals(aSymbolicName)) {
 				if (tempBundleMatch != null) {
 					if (tempBundleMatch.getVersion().compareTo(tempBundleCandidate.getVersion()) < 0) {
@@ -147,8 +163,22 @@ private Bundle findBundle(String aSymbolicName) {
 				}
 
 				tempBundleMatch = tempBundleCandidate;
+			} else {
+				Bundle tempRecursionCandidate
+						= findBundleRecursive(aSymbolicName, tempBundleCandidate, someSeenBundles);
+
+				if (tempRecursionCandidate != null) {
+					if (tempBundleMatch != null) {
+						if (tempBundleMatch.getVersion().compareTo(tempBundleCandidate.getVersion()) < 0) {
+							// already-found matches' version is less than candidates' version
+							continue;
+						}
+					}
+					tempBundleMatch = tempRecursionCandidate;
+				}
 			}
 		}
+
 		return tempBundleMatch;
 	}