Better handling of malformed desscriptor names

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@271923 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/optional/ejb/GenericDeploymentTool.java

@@ -574,8 +574,10 @@ public class GenericDeploymentTool implements EJBDeploymentTool {
 
             if (endBaseName != -1) {
                 baseName = descriptorFileName.substring(0, endBaseName);
+            } else {
+                throw new BuildException("Unable to determine jar name " 
+                    + "from descriptor \"" + descriptorFileName + "\"");
             }
-            baseName = descriptorFileName.substring(0, endBaseName);
         } else if (config.namingScheme.getValue().equals(EjbJar.NamingScheme.DIRECTORY)) {
             File descriptorFile = new File(config.descriptorDir, descriptorFileName);
             String path = descriptorFile.getAbsolutePath();