Mapping With a null Default Timestamp Causes NullPointerException on Merge

[dadoonet]

I have a field with a null default _timestamp value and when I try to update the mapping I get a server error caused by a NullPointerException

[2015-01-08 17:28:56,040][DEBUG][action.admin.indices.mapping.put] [...] failed to put mappings on indices [[feed_170_v1, feed_204_v1, feed_229_v1, feed_232_v1, feed_239_v1, feed_248_v1, feed_268_v1, feed_256_v1, feed_272_v1, feed_159_v1, feed_255_v1, feed_164_v1, feed_259_v1, feed_266_v1, feed_188_v1, feed_240_v1, feed_233_v1, feed_13_v1, feed_184_v1, feed_261_v1, feed_267_v1, feed_271_v1, feed_257_v1, feed_172_v1, feed_238_v1, feed_254_v1, feed_223_v1, feed_274_v1, feed_203_v1, feed_269_v1, feed_262_v1, feed_205_v1, feed_168_v1, feed_219_v1, feed_253_v1, feed_251_v1, feed_173_v1, feed_252_v1, feed_210_v1, feed_216_v1, feed_218_v1, feed_118_v1, feed_273_v1, feed_227_v1, feed_166_v1, feed_213_v1, feed_226_v1]], type [history]
java.lang.NullPointerException
        at org.elasticsearch.index.mapper.internal.TimestampFieldMapper.merge(TimestampFieldMapper.java:287)
        at org.elasticsearch.index.mapper.object.ObjectMapper.merge(ObjectMapper.java:936)
        at org.elasticsearch.index.mapper.DocumentMapper.merge(DocumentMapper.java:693)
        at org.elasticsearch.cluster.metadata.MetaDataMappingService$4.execute(MetaDataMappingService.java:508)
        at org.elasticsearch.cluster.service.InternalClusterService$UpdateTask.run(InternalClusterService.java:329)
        at org.elasticsearch.common.util.concurrent.PrioritizedEsThreadPoolExecutor$TieBreakingPrioritizedRunnable.run(PrioritizedEsThreadPoolExecutor.java:153)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)

https://github.com/elasticsearch/elasticsearch/blob/v1.4.2/src/main/java/org/elasticsearch/index/mapper/internal/TimestampFieldMapper.java#L286

Looks like the existence of default timestamp is not checked before use. The next line also has the same issue -- uses of default timestamp without checked to see if it's not null.

To reproduce:

$ curl -XPUT localhost:9200/twitter2
# {"acknowledged":true}

$ curl -XPUT localhost:9200/twitter2/tweet/_mapping -d '{
     "tweet" : {
         "_timestamp" : {
             "enabled" : true,
             "default" : null
         }
     }
}'
# {"acknowledged":true}

$ curl -XPUT localhost:9200/twitter2/tweet/_mapping -d '{
     "tweet" : {
         "_timestamp" : {
             "enabled" : true,
             "default" : null
         },
         "properties": {
             "user": {"type": "string"}
         }
     }
}'
# {"error":"NullPointerException[null]","status":500} Yikes!

Closes #9204.

[rjernst]

I think you can just do the == null part of this and the next if condition, since if the other were equal to null, we would have already returned in the first if?

if (x == null && y == null) return
if (x == null) ...
else if (y == null) ...
else // x and y are not null

[dadoonet]

very true!

[rjernst]

LGTM, just 2 minor comments.

[dadoonet]

Thanks. PR updated.

[rjernst]

LGTM