Should fix bug 434 <http://helma.org/bugs/show_bug.cgi?id=434>

* Synchronize all methods that call/rely on update().
* Make sure repositories and resources are not null after update() has been called.

src/helma/framework/repository/AbstractRepository.java

@@ -97,7 +97,7 @@ public abstract class AbstractRepository implements Repository {
      * If the name can't be resolved to a resource, a resource object is returned
      * for which {@link Resource exists()} returns <code>false<code>.
      */
-    public Resource getResource(String name) {
+    public synchronized Resource getResource(String name) {
         update();
 
         Resource res = (Resource) resources.get(name);
@@ -112,7 +112,7 @@ public abstract class AbstractRepository implements Repository {
     /**
      * Get an iterator over the resources contained in this repository.
      */
-    public Iterator getResources() {
+    public synchronized Iterator getResources() {
         update();
 
         return resources.values().iterator();
@@ -121,7 +121,7 @@ public abstract class AbstractRepository implements Repository {
     /**
      * Get an iterator over the sub-repositories contained in this repository.
      */
-    public Repository[] getRepositories() {
+    public synchronized Repository[] getRepositories() {
         update();
 
         return repositories;
@@ -138,7 +138,7 @@ public abstract class AbstractRepository implements Repository {
      * Get a deep list of this repository's resources, including all resources
      * contained in sub-reposotories.
      */
-    public List getAllResources() throws IOException {
+    public synchronized List getAllResources() throws IOException {
         update();
 
         ArrayList allResources = new ArrayList();

src/helma/framework/repository/FileRepository.java

@@ -115,7 +115,7 @@ public class FileRepository extends AbstractRepository {
         return directory.lastModified();
     }
 
-    public long getChecksum() throws IOException {
+    public synchronized long getChecksum() throws IOException {
         // delay checksum check if already checked recently
         if (System.currentTimeMillis() > lastChecksumTime + cacheTime) {
 
@@ -141,8 +141,11 @@ public class FileRepository extends AbstractRepository {
     public synchronized void update() {
         if (!directory.exists()) {
             repositories = new Repository[0];
-            if (resources != null)
+            if (resources != null) {
+                resources = new HashMap();
+            } else {
                 resources.clear();
+            }
             lastModified = 0;
             return;
         }

src/helma/framework/repository/ZipRepository.java

@@ -95,7 +95,9 @@ public final class ZipRepository extends AbstractRepository {
     }
 
     public synchronized void update() {
-        if (file.lastModified() != lastModified) {
+        if (file.lastModified() != lastModified ||
+                repositories == null ||
+                resources == null) {
             lastModified = file.lastModified();
             ZipFile zipfile = null;