Suppress "ignoring compiler setting" warning in javac if the user

hasn't set the compiler.

PR: 13246


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@273402 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -755,8 +755,10 @@ public class Javac extends MatchingTask {
         String compilerImpl = getCompilerVersion();
         if (fork) {
             if (isJdkCompiler(compilerImpl)) {
-                log("Since fork is true, ignoring compiler setting.",
-                    Project.MSG_WARN);
+                if (facade.hasBeenSet()) {
+                    log("Since fork is true, ignoring compiler setting.",
+                        Project.MSG_WARN);
+                }
                 compilerImpl = "extJavac";
             } else {
                 log("Since compiler setting isn't classic or modern,"

src/main/org/apache/tools/ant/util/facade/FacadeTaskHelper.java

@@ -164,4 +164,14 @@ public class FacadeTaskHelper {
         tmp.copyInto(res);
         return res;
     }
+
+    /**
+     * Tests whether the implementation has been chosen by the user
+     * (either via a magic property or explicitly.
+     *
+     * @since Ant 1.5.2
+     */
+    public boolean hasBeenSet() {
+        return userChoice != null || magicValue != null;
+    }
 }

src/testcases/org/apache/tools/ant/util/facade/FacadeTaskHelperTest.java

@@ -84,4 +84,17 @@ public class FacadeTaskHelperTest extends TestCase {
         fth.setImplementation("baz");
         assertEquals("baz", fth.getImplementation());
     }
+
+    public void testHasBeenSet() {
+        FacadeTaskHelper fth = new FacadeTaskHelper("foo");
+        assertTrue("nothing set", !fth.hasBeenSet());
+        fth.setMagicValue(null);
+        assertTrue("magic has not been set", !fth.hasBeenSet());
+        fth.setMagicValue("foo");
+        assertTrue("magic has been set", fth.hasBeenSet());
+        fth.setMagicValue(null);
+        assertTrue(!fth.hasBeenSet());
+        fth.setImplementation("baz");
+        assertTrue("set explicitly", fth.hasBeenSet());
+    }
 }