Correctly handle the case where one of the defaults.properties files

cannot be found.
Submitted by:	Nico Seessle <nico@seessle.de>


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@267957 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/Project.java

@@ -145,6 +145,9 @@ public class Project {
         try {
             Properties props = new Properties();
             InputStream in = this.getClass().getResourceAsStream(defs);
+            if (in == null) { 
+                throw new BuildException("Can't load default task list");
+            }
             props.load(in);
             in.close();
 
@@ -170,6 +173,9 @@ public class Project {
         try{
             Properties props = new Properties();
             InputStream in = this.getClass().getResourceAsStream(dataDefs);
+            if (in == null) { 
+                throw new BuildException("Can't load default datatype list");
+            }
             props.load(in);
             in.close();