`NullPointerException` from `ResolvedRecursiveType` (regression due to fix for #2331)

[michael-simons]

Hello,

the backport for #2331 into 2.9.9, specific 2.9.9.2, which comes through 2.9.9.20190727, leads to a null pointer exception together with the JDK 8 module:

Given

package ac.simons;

import java.io.IOException;

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;

public class JacksonTest {

	@Test
	void shouldWorkWithoutJdk8Module() throws IOException {
		ObjectMapper objectMapper = new ObjectMapper();

		final JsonNode responseNode = objectMapper.readTree("{}");
		Assertions.assertNotNull(responseNode);
	}

	@Test
	void shouldWorkWithJdk8Module() throws IOException {
		ObjectMapper objectMapper = new ObjectMapper()
			.registerModule(new Jdk8Module());

		final JsonNode responseNode = objectMapper.readTree("{}");
		Assertions.assertNotNull(responseNode);
	}
}

It doesn't matter whether the object to be parsed is empty as above or contains data as for example

final JsonNode responseNode = objectMapper.readTree("{\"something\":\"foobar\"}");

Works with com.fasterxml.jackson:jackson-bom:2.9.9 and breaks with com.fasterxml.jackson:jackson-bom:2.9.9.20190727:

java.lang.NullPointerException
	at com.fasterxml.jackson.databind.type.ResolvedRecursiveType.getBindings(ResolvedRecursiveType.java:42)
	at com.fasterxml.jackson.databind.type.TypeFactory._fromAny(TypeFactory.java:1243)
	at com.fasterxml.jackson.databind.type.TypeFactory._fromParamType(TypeFactory.java:1452)
	at com.fasterxml.jackson.databind.type.TypeFactory._fromAny(TypeFactory.java:1221)
	at com.fasterxml.jackson.databind.type.TypeFactory._resolveSuperInterfaces(TypeFactory.java:1367)
	at com.fasterxml.jackson.databind.type.TypeFactory._fromClass(TypeFactory.java:1314)
	at com.fasterxml.jackson.databind.type.TypeFactory._fromAny(TypeFactory.java:1217)
	at com.fasterxml.jackson.databind.type.TypeFactory.constructType(TypeFactory.java:631)
	at com.fasterxml.jackson.databind.cfg.MapperConfig.constructType(MapperConfig.java:281)
	at com.fasterxml.jackson.databind.cfg.MapperConfig.introspectClassAnnotations(MapperConfig.java:311)
	at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory.findTypeDeserializer(BasicDeserializerFactory.java:1571)
	at com.fasterxml.jackson.databind.DeserializationContext.findRootValueDeserializer(DeserializationContext.java:483)
	at com.fasterxml.jackson.databind.ObjectMapper._findRootDeserializer(ObjectMapper.java:4191)
	at com.fasterxml.jackson.databind.ObjectMapper._readTreeAndClose(ObjectMapper.java:4052)
	at com.fasterxml.jackson.databind.ObjectMapper.readTree(ObjectMapper.java:2552)
	at ac.simons.JacksonTest.shouldWorkWithJdk8Module(JacksonTest.java:27)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:675)
	at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:125)
	at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:132)
	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:124)
	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:74)
	at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
	at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:104)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:62)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:43)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:35)
	at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
	at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:202)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:198)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:135)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:69)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:135)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
	at java.util.ArrayList.forEach(ArrayList.java:1257)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
	at java.util.ArrayList.forEach(ArrayList.java:1257)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:229)
	at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:197)
	at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:211)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:191)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:128)
	at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:69)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

Please find a sample project attached.

jacksonissue.zip

[VanCoding]

I can confirm this bug. I just wasted my morning trying to find out what's going on. Turned out to be the 2.9.9.2 release.

[chriskessel]

Confirmed here too. Using JDK 11. In my case, when Dropwizard is trying to parse its yml config file:

java.lang.NullPointerException
	at com.fasterxml.jackson.databind.type.ResolvedRecursiveType.getBindings(ResolvedRecursiveType.java:42)
	at com.fasterxml.jackson.databind.type.TypeFactory._fromAny(TypeFactory.java:1243)
	at com.fasterxml.jackson.databind.type.TypeFactory._fromParamType(TypeFactory.java:1452)
	at com.fasterxml.jackson.databind.type.TypeFactory._fromAny(TypeFactory.java:1221)
	at com.fasterxml.jackson.databind.type.TypeFactory._resolveSuperInterfaces(TypeFactory.java:1367)
	at com.fasterxml.jackson.databind.type.TypeFactory._fromClass(TypeFactory.java:1314)
	at com.fasterxml.jackson.databind.type.TypeFactory._fromAny(TypeFactory.java:1217)
	at com.fasterxml.jackson.databind.type.TypeFactory.constructType(TypeFactory.java:631)
	at com.fasterxml.jackson.databind.cfg.MapperConfig.constructType(MapperConfig.java:281)
	at com.fasterxml.jackson.databind.cfg.MapperConfig.introspectClassAnnotations(MapperConfig.java:311)
	at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory.findTypeDeserializer(BasicDeserializerFactory.java:1571)
	at com.fasterxml.jackson.databind.DeserializationContext.findRootValueDeserializer(DeserializationContext.java:483)
	at com.fasterxml.jackson.databind.ObjectMapper._findRootDeserializer(ObjectMapper.java:4191)
	at com.fasterxml.jackson.databind.ObjectMapper._readValue(ObjectMapper.java:3980)
	at com.fasterxml.jackson.databind.ObjectMapper.readTree(ObjectMapper.java:2385)
	at io.dropwizard.configuration.BaseConfigurationFactory.build(BaseConfigurationFactory.java:81)```

[rkraneis]

We are also affected.

[chadlwilson]

In our case the issue is observed using spring-data-redis's Jackson2HashMapper; but looks like a similar problem; details here.

(Edit: just checked and we initialize our Jackson2HashMapper with the default ObjectMapper injected via Spring; which itself has the JDK8 module registered by default via the Jackson2ObjectMapperBuilder's "well-known modules" support; so it seems quite possible it's the same root cause.)

It would also be good if we could get the changelog fixed too; the change that broke this was incorrectly included in the changelog for 2.9.9.1 - not 2.9.9.2 when it was actually released.

[cowtowncoder]

I'll update the changelog first. Reproduction with Java8 module is interesting since it is unclear why and how that should have any effect (obviously basic readTree() functionality is heavily tested in databind itself, but won't fail somehow).

I will start with the test case but will need to figure out how to reproduce without other modules as tests from jackson-databind can not rely on modules (which depend on databind).

[cowtowncoder]

I can reproduce this: looks like NPE is indirectly triggered by call to JavaType.getBindings();, which is not needed if no TypeModifiers registered. Bit odd that existing test class TestTypeModifiers does NOT somehow hit that... which is too bad as that would have caught the problem.

[cowtowncoder]

Ah. This is due to JsonNode having recursive self-reference via Iterable<JsonNode>.