BZ 62071 - fix error message when fileset.setFile is called twice

WHATSNEW

@@ -30,6 +30,11 @@ Fixed bugs:
    streams of a process, could end up being truncated.
    Bugzilla Report 58833, 58451
 
+ * <fileset>/<zipfileset>/<tarfileset> will now throw an exception
+   with a more useful error message when setFile is called twice on
+   the same instance.
+   Bugzilla Report 62071
+
 Other changes:
 --------------
 

src/main/org/apache/tools/ant/types/AbstractFileSet.java

@@ -232,7 +232,16 @@ public abstract class AbstractFileSet extends DataType
         if (isReference()) {
             throw tooManyAttributes();
         }
-        if (getDir() != null) {
+        if (fileAttributeUsed) {
+            if (getDir().equals(file.getParentFile())) {
+                String[] includes = defaultPatterns.getIncludePatterns(getProject());
+                if (includes.length == 1 && includes[0].equals(file.getName())) {
+                    // NOOP, setFile has been invoked twice with the same parameter
+                    return;
+                }
+            }
+            throw new BuildException("setFile cannot be called twice with different arguments");
+        } else if (getDir() != null) {
             throw dirAndFileAreMutuallyExclusive();
         }
         setDir(file.getParentFile());

src/tests/junit/org/apache/tools/ant/types/AbstractFileSetTest.java

@@ -244,4 +244,24 @@ public abstract class AbstractFileSetTest {
         File dir = f1.getDir(project);
         assertEquals("Dir is basedir", dir, project.getBaseDir());
     }
+
+    @Test
+    public void canCallSetFileTwiceWithSameArgument() {
+        AbstractFileSet f = getInstance();
+        f.setFile(new File("/a"));
+        f.setFile(new File("/a"));
+        // really only asserts no exception is thrown
+    }
+
+    @Test
+    public void cantCallSetFileTwiceWithDifferentArguments() {
+        AbstractFileSet f = getInstance();
+        f.setFile(new File("/a"));
+        try {
+            f.setFile(new File("/b"));
+            fail("expected an exception");
+        } catch (BuildException ex) {
+            assertEquals("setFile cannot be called twice with different arguments", ex.getMessage());
+        }
+    }
 }