Fix #1767 - NPE on OptionSpec.getValue() (IScoped)

src/main/java/picocli/CommandLine.java

@@ -5995,6 +5995,16 @@ private Model() {}
          * @since 4.0
          */
         public interface IScope extends IGetter, ISetter {}
+
+        /** This interface provides access to an {@link IScope} instance. 
+         * @since 4.7
+         */
+        public interface IScoped {
+            /** Get the {@link IScope} instance.
+             * 
+             *  @return {@link IScope} instance */
+            IScope getScope();
+        }
 
         /** Customizable getter for obtaining the current value of an option or positional parameter.
          * When an option or positional parameter is matched on the command line, its getter or setter is invoked to capture the value.
@@ -9166,9 +9176,26 @@ private String defaultValueFromProvider() {
              * @return whether this argument applies to all descendent subcommands of the command where it is defined
              * @since 4.3 */
             public ScopeType scopeType() { return scopeType; }
+
+            /** Check whether the {@link #getValue()} method is able to get an actual value from the current {@link #getter()}. 
+             * @since 4.7 */
+            public boolean isValueGettable() {
+                if (getter instanceof IScoped) {
+                    IScoped scoped = (IScoped) getter;
+                    IScope scope = scoped.getScope();
+                    if ( scope==null ) { return false; }
+                    try {
+                        return scope.get() != null;
+                    } catch (Exception e) {
+                        return false;
+                    }
+                }
+                return true;
+            }
 
             /** Returns the current value of this argument. Delegates to the current {@link #getter()}. */
             public <T> T getValue() throws PicocliException {
+                if ( !isValueGettable() ) { return null; }
                 try {
                     return getter.<T>get();
                 } catch (PicocliException ex) { throw ex;
@@ -12018,11 +12045,14 @@ private static UnmatchedArgsBinding buildUnmatchedForMember(final IAnnotatedElem
             }
         }
 
-        static class FieldBinding implements IGetter, ISetter {
+        static class FieldBinding implements IGetter, ISetter, IScoped {
             private final IScope scope;
             private final Field field;
             FieldBinding(Object scope, Field field) { this(ObjectScope.asScope(scope), field); }
             FieldBinding(IScope scope, Field field) { this.scope = scope; this.field = field; }
+            public IScope getScope() {
+                return scope;
+            }
             public <T> T get() throws PicocliException {
                 Object obj;
                 try { obj = scope.get(); }
@@ -12051,7 +12081,7 @@ public String toString() {
                         field.getDeclaringClass().getName(), field.getName());
             }
         }
-        static class MethodBinding implements IGetter, ISetter {
+        static class MethodBinding implements IGetter, ISetter, IScoped {
             private final IScope scope;
             private final Method method;
             private final CommandSpec spec;
@@ -12061,6 +12091,9 @@ static class MethodBinding implements IGetter, ISetter {
                 this.method = method;
                 this.spec = spec;
             }
+            public IScope getScope() {
+                return scope;
+            }
             @SuppressWarnings("unchecked") public <T> T get() { return (T) currentValue; }
             public <T> T set(T value) throws PicocliException {
                 Object obj;

src/test/java/picocli/Issue1767.java

@@ -0,0 +1,41 @@
+package picocli;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static picocli.CommandLine.ScopeType.INHERIT;
+
+import java.util.concurrent.Callable;
+
+import org.junit.Test;
+
+import picocli.CommandLine.ArgGroup;
+import picocli.CommandLine.Command;
+import picocli.CommandLine.IFactory;
+import picocli.CommandLine.Model.CommandSpec;
+import picocli.CommandLine.Option;
+import picocli.CommandLine.Spec;
+
+public class Issue1767 {
+    @Command(name = "test")
+    static class TestCommand implements Callable<Integer> {
+        @ArgGroup TestArgGroup testArgGroup;
+        @Spec CommandSpec spec;
+
+        public static class TestArgGroup {
+            @Option(names = "-r")
+            public Integer option1;
+        }
+
+        @Override
+        public Integer call() throws Exception {
+            Integer value = spec.options().get(0).getValue();
+            return value==null ? 0 : value;
+        }
+    }
+
+    @Test
+    public void testIssue1772() {
+        assertEquals(5, new CommandLine(new TestCommand()).execute("-r", "5"));
+        assertEquals(0, new CommandLine(new TestCommand()).execute());
+    }
+}