[remkop#1316] Bugfix: Avoid DuplicateOptionAnnotationsException thr…

…own on `mixinStandardHelpOptions` for subcommands when parent has `scope = INHERIT` by `picocli-codegen` annotation processor.

Closes remkop#1316

RELEASE-NOTES.md

@@ -21,6 +21,7 @@ Picocli follows [semantic versioning](http://semver.org/).
 ## <a name="4.6.2-fixes"></a> Fixed issues
 * [#1303] Bugfix: Prevent `IllegalArgumentException: argument type mismatch` error in method subcommands with inherited mixed-in standard help options. Thanks to [Andreas Deininger](https://github.com/deining) for raising this.
 * [#1300] Bugfix: Avoid spurious warning "Could not set initial value for field boolean" when reusing `CommandLine` with ArgGroup. Thanks to [Yashodhan Ghadge](https://github.com/codexetreme) for raising this.
+* [#1316] Bugfix: Avoid `DuplicateOptionAnnotationsException` thrown on `mixinStandardHelpOptions` for subcommands when parent has `scope = INHERIT` by `picocli-codegen` annotation processor. Thanks to [Philippe Charles](https://github.com/charphi) for raising this.
 * [#1296] DOC: add Kotlin code samples to user manual; other user manual improvements. Thanks to [Andreas Deininger](https://github.com/deining) for the pull request.
 * [#1299] DOC: Link to `IParameterPreprocessor` from `IParameterConsumer` javadoc. Thanks to [Andreas Deininger](https://github.com/deining) for the pull request.
 * [#1304] DOC: Manual, chapter '17.9 Inherited Command Attributes': added Kotlin version of code sample. Thanks to [Andreas Deininger](https://github.com/deining) for the pull request.

picocli-annotation-processing-tests/src/test/java/picocli/annotation/processing/tests/Issue1316Test.java

@@ -0,0 +1,24 @@
+package picocli.annotation.processing.tests;
+
+import com.google.testing.compile.Compilation;
+import com.google.testing.compile.JavaFileObjects;
+import org.junit.Test;
+
+import javax.annotation.processing.Processor;
+
+import static com.google.testing.compile.CompilationSubject.assertThat;
+import static com.google.testing.compile.Compiler.javac;
+
+public class Issue1316Test {
+    @Test
+    public void testIssue1316() {
+        Processor processor = new AnnotatedCommandSourceGeneratorProcessor();
+        Compilation compilation =
+                javac()
+                        .withProcessors(processor)
+                        .compile(JavaFileObjects.forResource(
+                                "picocli/issue1316/Example.java"));
+
+        assertThat(compilation).succeeded();
+    }
+}

picocli-annotation-processing-tests/src/test/resources/picocli/issue1316/Example.java

@@ -0,0 +1,13 @@
+package picocli.issue1316;
+
+import picocli.CommandLine;
+import picocli.AutoComplete;
+
+@CommandLine.Command(
+        name = "example",
+        mixinStandardHelpOptions = true,
+        scope = CommandLine.ScopeType.INHERIT,
+        subcommands = AutoComplete.GenerateCompletion.class
+)
+public class Example {
+}

src/main/java/picocli/CommandLine.java

@@ -7156,9 +7156,11 @@ public CommandSpec negatableOptionTransformer(INegatableOptionTransformer newVal
              * @see Command#mixinStandardHelpOptions() */
             public CommandSpec mixinStandardHelpOptions(boolean newValue) {
                 if (newValue) {
-                    CommandSpec mixin = CommandSpec.forAnnotatedObject(new AutoHelpMixin(), new DefaultFactory());
-                    mixin.inherited = this.inherited();
-                    addMixin(AutoHelpMixin.KEY, mixin);
+                    if (!mixins.containsKey(AutoHelpMixin.KEY)) { // #1316 avoid DuplicateOptionAnnotationsException
+                        CommandSpec mixin = CommandSpec.forAnnotatedObject(new AutoHelpMixin(), new DefaultFactory());
+                        mixin.inherited = this.inherited();
+                        addMixin(AutoHelpMixin.KEY, mixin);
+                    }
                 } else {
                     CommandSpec helpMixin = mixins.remove(AutoHelpMixin.KEY);
                     if (helpMixin != null) {

src/test/java/picocli/InheritedOptionTest.java

@@ -543,4 +543,18 @@ void sub(@Option(names = "-foo") int foo) {
         new CommandLine(app).execute("sub", "-foo", "42" );
         assertEquals(42, app.subCalled);
     }
+
+    @Test
+    public void testIssue1316() {
+        @CommandLine.Command(
+                name = "example",
+                mixinStandardHelpOptions = true,
+                scope = CommandLine.ScopeType.INHERIT,
+                subcommands = AutoComplete.GenerateCompletion.class
+        )
+        class Example { }
+
+        // see also picocli-annotation-processing-tests/src/test/java/picocli/annotation/processing/tests/Issue1316Test.java
+        new CommandLine(new Example()); // succeeds without error
+    }
 }