Fix argument conversion in QuerydslPredicateBuilder.

We now consider the correct argument type instead of checking assignability of the actual property type against the input value.

Closes: #2649
Original Pull Request: #2650

Author: mp911de

src/main/java/org/springframework/data/querydsl/binding/QuerydslPredicateBuilder.java

@@ -176,30 +176,29 @@ private Path<?> getPath(PathInformation path, QuerydslBindings bindings) {
 	 */
 	private Collection<Object> convertToPropertyPathSpecificType(List<?> source, PathInformation path) {
 
-		Class<?> targetType = path.getLeafType();
-
 		if (source.isEmpty() || isSingleElementCollectionWithEmptyItem(source)) {
 			return Collections.emptyList();
 		}
 
+		TypeDescriptor targetType = getTargetTypeDescriptor(path);
 		Collection<Object> target = new ArrayList<>(source.size());
 
 		for (Object value : source) {
-			target.add(getValue(path, targetType, value));
+			target.add(getValue(targetType, value));
 		}
 
 		return target;
 	}
 
 	@Nullable
-	private Object getValue(PathInformation path, Class<?> targetType, Object value) {
+	private Object getValue(TypeDescriptor targetType, Object value) {
 
-		if (ClassUtils.isAssignableValue(targetType, value)) {
+		if (ClassUtils.isAssignableValue(targetType.getType(), value)) {
 			return value;
 		}
 
-		if (conversionService.canConvert(value.getClass(), targetType)) {
-			return conversionService.convert(value, TypeDescriptor.forObject(value), getTargetTypeDescriptor(path));
+		if (conversionService.canConvert(value.getClass(), targetType.getType())) {
+			return conversionService.convert(value, TypeDescriptor.forObject(value), targetType);
 		}
 
 		return value;

src/test/java/org/springframework/data/querydsl/binding/QuerydslPredicateBuilderUnitTests.java

@@ -20,6 +20,7 @@
 import static org.springframework.test.util.ReflectionTestUtils.*;
 
 import java.text.ParseException;
+import java.util.Arrays;
 import java.util.List;
 
 import org.joda.time.DateTime;
@@ -198,6 +199,18 @@ void bindsDateCorrectly() throws ParseException {
 		assertThat(predicate).isEqualTo(QUser.user.dateOfBirth.eq(format.parseDateTime(date).toDate()));
 	}
 
+	@Test
+	void resolvesCommaSeparatedArgumentToListCorrectly() {
+
+		values.add("nickNames", "Walt,Heisenberg");
+
+		Predicate predicate = builder.getPredicate(USER_TYPE, values, DEFAULT_BINDINGS);
+
+		Constant<Object> constant = (Constant<Object>) ((List<?>) getField(getField(predicate, "mixin"), "args")).get(0);
+
+		assertThat(constant.getConstant()).isEqualTo(Arrays.asList("Walt", "Heisenberg"));
+	}
+
 	@Test // DATACMNS-883
 	void automaticallyInsertsAnyStepInCollectionReference() {