Fix gc's usage of progress monitor

Change-Id: I8dcdf0b83e91e6132dc490e8ec53818220773c94
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit/src/org/eclipse/jgit/storage/file/GC.java

@@ -137,6 +137,7 @@ public class GC {
 	 * @throws IOException
 	 */
 	public Collection<PackFile> gc() throws IOException {
+		pm.start(6 /* tasks */);
 		packRefs();
 		// TODO: implement reflog_expire(pm, repo);
 		Collection<PackFile> newPacks = repack();
@@ -262,34 +263,38 @@ public class GC {
 		if (fanout != null && fanout.length > 0) {
 			pm.beginTask(JGitText.get().pruneLooseUnreferencedObjects,
 					fanout.length);
-			for (String d : fanout) {
-				pm.update(1);
-				if (d.length() != 2)
-					continue;
-				File[] entries = new File(objects, d).listFiles();
-				if (entries == null)
-					continue;
-				for (File f : entries) {
-					String fName = f.getName();
-					if (fName.length() != Constants.OBJECT_ID_STRING_LENGTH - 2)
+			try {
+				for (String d : fanout) {
+					pm.update(1);
+					if (d.length() != 2)
 						continue;
-					if (f.lastModified() >= expireDate)
+					File[] entries = new File(objects, d).listFiles();
+					if (entries == null)
 						continue;
-					try {
-						ObjectId id = ObjectId.fromString(d + fName);
-						if (objectsToKeep.contains(id))
+					for (File f : entries) {
+						String fName = f.getName();
+						if (fName.length() != Constants.OBJECT_ID_STRING_LENGTH - 2)
 							continue;
-						if (indexObjects == null)
-							indexObjects = listNonHEADIndexObjects();
-						if (indexObjects.contains(id))
+						if (f.lastModified() >= expireDate)
 							continue;
-						deletionCandidates.put(id, f);
-					} catch (IllegalArgumentException notAnObject) {
-						// ignoring the file that does not represent loose
-						// object
-						continue;
+						try {
+							ObjectId id = ObjectId.fromString(d + fName);
+							if (objectsToKeep.contains(id))
+								continue;
+							if (indexObjects == null)
+								indexObjects = listNonHEADIndexObjects();
+							if (indexObjects.contains(id))
+								continue;
+							deletionCandidates.put(id, f);
+						} catch (IllegalArgumentException notAnObject) {
+							// ignoring the file that does not represent loose
+							// object
+							continue;
+						}
 					}
 				}
+			} finally {
+				pm.endTask();
 			}
 		}
 		if (deletionCandidates.isEmpty())