@JsonDeserialize on Map with contentUsing custom deserializer overwrites default behavior

[joerglaumann]

I recently updated from version 2.3.3 to 2.5.1 and encountered a new issue with our custom deserializers. They either seemed to stop working or were active on the wrong fields.
I could narrow it down to some change in version 2.4.4 (2.4.3 is still working for me)

I wrote a test to show this behavior. It seems to appear when there a two maps with the same key and value types in a bean, and only one of them has a custom deserializer. The deserializer is then falsely used either for both or none of the maps.

This test works for me in version 2.4.3 and fails with higher versions.

import static org.junit.Assert.assertEquals;

import java.io.IOException;
import java.util.Map;

import org.junit.Test;

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.deser.std.StdDeserializer;

public class DeserializeTest {

    @Test
    public void testIt() throws Exception {
        ObjectMapper om = new ObjectMapper();
        String json = "{\"map1\":{\"a\":1},\"map2\":{\"a\":1}}";
        TestBean bean = om.readValue(json.getBytes(), TestBean.class);

        assertEquals(100, bean.getMap1().get("a").intValue());
        assertEquals(1, bean.getMap2().get("a").intValue());
    }

    public static class TestBean {

        @JsonProperty("map1")
        @JsonDeserialize(contentUsing = CustomDeserializer.class)
        Map<String, Integer> map1;

        @JsonProperty("map2")
        Map<String, Integer> map2;

        public Map<String, Integer> getMap1() {
            return map1;
        }

        public void setMap1(Map<String, Integer> map1) {
            this.map1 = map1;
        }

        public Map<String, Integer> getMap2() {
            return map2;
        }

        public void setMap2(Map<String, Integer> map2) {
            this.map2 = map2;
        }
    }

    public static class CustomDeserializer extends StdDeserializer<Integer> {

        public CustomDeserializer() {
            super(Integer.class);
        }

        @Override
        public Integer deserialize(JsonParser p, DeserializationContext ctxt) throws IOException, JsonProcessingException {
            Integer value = p.readValueAs(Integer.class);
            return value * 100;
        }
    }
}

[cowtowncoder]

That does not sound good.

Looking at 2.4.4, my first thought was this could be due to #604 (fixed in 2.4.5 by #635), but if 2.4.5 also fails, this is probably not the case.

Thank you for reproduction, I will try to figure out what is causing the failure.

[cowtowncoder]

Ok, yes. It is due to #604 as well. Looks like checks to prevent incorrect caching were still not strict enough.
On plus side, easy to fix.

I will probably release 2.4.5.1 "micro-patch" of just jackson-databind soon (and not release full set of all other artifacts). And this fix along with others will get in 2.4.6 when it gets released.

[cowtowncoder]

I just released 2.4.5.1, should be available via Maven in an hour. Note that only jackson-databind released, as per above; 2.4.5 of other components may (and needs to be) used.

[joerglaumann]

Thank you for the quick resultion!

[cowtowncoder]

Thank you for reporting this! I need to do bit more work on 2.5 to ensure other cases are not affected, since Collection caching was also extended. These are difficult ones to trouble-shoot, but knowing the problem it is easier to write proper tests now -- reproduction requires specific sequence of resolution calls (custom one first vs last).