ensure that property w/ fileset applies to a single file

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@292552 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/Checksum.java

@@ -320,7 +320,8 @@ public class Checksum extends MatchingTask implements Condition {
                                              + "when Property is specified");
                 }
             } else {
-                if (filesets.size() > 1) {
+                if (filesets.size() > 1
+                    || ((FileSet) filesets.get(0)).size() > 1) {
                     throw new BuildException("Multiple files cannot be used "
                                              + "when Property is specified");
                 }