Consider primitive types in explicit type check in DefaultConverter

Follow-up on #3009.

Author: sratz

bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/UpdateStrategy.java

@@ -679,7 +679,7 @@ static final class DefaultConverter implements IConverter<Object, Object> {
 		public Object convert(Object fromObject) {
 			// Explicit cast necessary due to potential type erasure
 			if (toType instanceof Class<?> clazz) {
-				return clazz.cast(fromObject);
+				return (clazz.isPrimitive() ? autoboxed(clazz) : clazz).cast(fromObject);
 			}
 			return fromObject;
 		}

tests/org.eclipse.jface.tests.databinding/src/org/eclipse/core/tests/databinding/UpdateStrategyTest.java

@@ -30,6 +30,7 @@
 import org.eclipse.core.databinding.conversion.IConverter;
 import org.eclipse.core.databinding.conversion.text.NumberToStringConverter;
 import org.eclipse.core.databinding.conversion.text.StringToNumberConverter;
+import org.eclipse.core.databinding.observable.value.AbstractObservableValue;
 import org.eclipse.core.databinding.observable.value.IObservableValue;
 import org.eclipse.core.databinding.observable.value.WritableValue;
 import org.eclipse.core.internal.databinding.conversion.DateToStringConverter;
@@ -370,4 +371,27 @@ public void testDefaultConverterWithTypeErasure() {
 		RuntimeException ex = assertThrows(RuntimeException.class, () -> strategy.convert(new HashSet<>()));
 		assertTrue("Type erasure was missed", ex.getCause() instanceof ClassCastException);
 	}
+
+	// https://github.com/eclipse-platform/eclipse.platform.ui/pull/3009#issuecomment-3012956414
+	@Test
+	public void testDefaultConverterWithPrimitiveTypeAsDestinationAndNonClassTypeAsSourceType() {
+		IObservableValue<Boolean> source = new AbstractObservableValue() {
+			@Override
+			public Object getValueType() {
+				return new Object(); // non-class type, happens e.g. in EMF databinding
+			}
+
+			@Override
+			protected Object doGetValue() {
+				return Boolean.TRUE;
+			}
+		};
+		WritableValue<Boolean> destination = WritableValue.withValueType(boolean.class);
+
+		UpdateStrategyStub<Object, Boolean> strategy = new UpdateStrategyStub<>();
+		strategy.fillDefaults(source, destination);
+
+		Boolean result = strategy.convert(source.getValue());
+		assertTrue(result);
+	}
 }