Added null check when getting manifest attributes for case of jar without manifest

* netx/net/sourceforge/jnlp/runtime/JNLPClassLoader.java: (getManifestAttribute) added check fo null manifest to prevent npe.
* /tests/netx/unit/net/sourceforge/jnlp/runtime/JNLPClassLoaderTest.java: added test for  npe from getManifestAttribute
* tests/test-extensions/net/sourceforge/jnlp/util/FileTestUtils.java: (createJarWithContents) enhanced to be able to create jar without manifest.

1 files changed, 14 insertions, 2 deletions

diff --git a/tests/test-extensions/net/sourceforge/jnlp/util/FileTestUtils.java b/tests/test-extensions/net/sourceforge/jnlp/util/FileTestUtils.java
index 828d6a5..1ce4935 100644
--- a/tests/test-extensions/net/sourceforge/jnlp/util/FileTestUtils.java
+++ b/tests/test-extensions/net/sourceforge/jnlp/util/FileTestUtils.java
@@ -89,13 +89,25 @@ public class FileTestUtils {
     }
 
     /* Creates a jar in a temporary directory, with the given name & file contents */
+    static public void createJarWithoutManifestContents(File jarFile, File... fileContents) throws Exception{
+        createJarWithContents(jarFile, null, fileContents);
+    }
+    
+    /* Creates a jar in a temporary directory, with the given name & file contents */
     static public void createJarWithContents(File jarFile, Manifest manifestContents, File... fileContents)
             throws Exception {
         /* Manifest quite evilly ignores all attributes if we don't specify a version! 
          * Make sure it's set here. */
-        manifestContents.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0");
+        if (manifestContents != null){
+            manifestContents.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0");
+        }
 
-        JarOutputStream jarWriter = new JarOutputStream(new FileOutputStream(jarFile), manifestContents);
+        JarOutputStream jarWriter;
+        if (manifestContents == null){
+            jarWriter = new JarOutputStream(new FileOutputStream(jarFile));
+        } else {
+            jarWriter = new JarOutputStream(new FileOutputStream(jarFile), manifestContents);
+        }
         for (File file : fileContents) {
             jarWriter.putNextEntry(new JarEntry(file.getName()));
             FileInputStream fileReader = new FileInputStream(file);