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

Faster bundle lookup via recursion.

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

@@ -84,7 +84,10 @@ public IClasspathEntry[] getClasspathEntries() {
 		addToList(tempEntryList, new String[][] { new String[] { "org.eclipse.xtext.common.types" } });
 		addToList(tempEntryList, new String[][] { new String[] { "org.jdom" }, new String[] { "org.jdom_jaxen" } });
 
-		addToList(tempEntryList, new String[][] { new String[] { "org.objectweb.asm" } });
+		// Recursion is necessary for org.objectweb.asm because xtext 2.16.x depends on 7.0.0 of that bundle, but
+		// Eclipse itself just uses 6.2.1, so we must recursively search the entire bundle tree in order to find all
+		// bundles.
+		addToList(tempEntryList, new String[][] { new String[] { "org.objectweb.asm" } }, true);
 
 		// convert the list to an array and return it
 		IClasspathEntry[] tempEntryArray = new IClasspathEntry[tempEntryList.size()];
@@ -102,13 +105,29 @@ public IClasspathEntry[] getClasspathEntries() {
 	 *            bundles that are part of a single combination)
 	 */
 	private void addToList(List<IClasspathEntry> aList, String[][] someBundleNames) {
+		addToList(aList, someBundleNames, false);
+	}
+
+	/**
+	 * Finds one of the provided combination of bundles and adds it to the classpath. If no combination is found, an
+	 * error is logged.
+	 * 
+	 * @param aList
+	 *            the classpath
+	 * @param someBundleNames
+	 *            an array of combinations of bundle names (outer array contains combinations, inner array contains the
+	 *            bundles that are part of a single combination)
+	 * @param aRecursiveFlag
+	 *            whether to recursively search the contexts of bundles
+	 */
+	private void addToList(List<IClasspathEntry> aList, String[][] someBundleNames, boolean aRecursiveFlag) {
 		StringBuffer tempBuffer = new StringBuffer();
 		for (String[] tempBundleNames : someBundleNames) {
 			StringBuffer tempInnerBuffer = new StringBuffer();
 			List<IClasspathEntry> tempList = new ArrayList<IClasspathEntry>();
 			boolean tempFoundAll = true;
 			for (String tempBundleName : tempBundleNames) {
-				IClasspathEntry tempEntry = getPluginEntry(findBundle(tempBundleName));
+				IClasspathEntry tempEntry = getPluginEntry(findBundle(tempBundleName, aRecursiveFlag));
 				if (tempEntry != null) {
 					tempList.add(tempEntry);
 				} else {
@@ -136,8 +155,9 @@ private void addToList(List<IClasspathEntry> aList, String[][] someBundleNames)
 						+ tempBuffer + "' to add it to a projects' classpath!"));
 	}
 
-	private Bundle findBundle(String aSymbolicName) {
-		return findBundleRecursive(aSymbolicName, FrameworkUtil.getBundle(JavaCore.class), new HashSet<>());
+	private Bundle findBundle(String aSymbolicName, boolean aRecursiveFlag) {
+		return findBundleRecursive(aSymbolicName, FrameworkUtil.getBundle(JavaCore.class),
+				aRecursiveFlag ? new HashSet<>() : null);
 	}
 
 	private Bundle findBundleRecursive(String aSymbolicName, Bundle aRootBundle, Set<Bundle> someSeenBundles) {
@@ -148,10 +168,12 @@ private Bundle findBundleRecursive(String aSymbolicName, Bundle aRootBundle, Set
 		}
 
 		for (Bundle tempBundleCandidate : aRootBundle.getBundleContext().getBundles()) {
-			if (someSeenBundles.contains(tempBundleCandidate)) {
-				continue;
-			} else {
-				someSeenBundles.add(tempBundleCandidate);
+			if (someSeenBundles != null) {
+				if (someSeenBundles.contains(tempBundleCandidate)) {
+					continue;
+				} else {
+					someSeenBundles.add(tempBundleCandidate);
+				}
 			}
 
 			if (tempBundleCandidate.getSymbolicName().equals(aSymbolicName)) {
@@ -163,7 +185,7 @@ private Bundle findBundleRecursive(String aSymbolicName, Bundle aRootBundle, Set
 				}
 
 				tempBundleMatch = tempBundleCandidate;
-			} else {
+			} else if (someSeenBundles != null) {
 				Bundle tempRecursionCandidate
 						= findBundleRecursive(aSymbolicName, tempBundleCandidate, someSeenBundles);