API endpoint api/admin/datasetfield/load allows invalid TSV (without error)

[pameyer]

The API endpoint for adding new metadata blocks appears to allow invalid blocks to be edited.

curl -X POST --data-binary @$tsv -H "Content-type: text/tab-separated-values" http://localhost:8080/api/admin/datasetfield/load appears successful; attempting to add a new datasetfield (to a draft dataset created through the native API, although that doesn't appear relevant) fails with:
"Dataset Save Failed - edu.harvard.iq.dataverse.engine.command.exception.CommandException: Command edu.harvard.iq.dataverse.engine.command.impl.UpdateDatasetCommand@16192b38 failed: null"
and
"The metadata could not be updated. Please contact Dataverse Support for assistance. Date/Time: 2017-02-01 18:55:23 Server: localhost.localdomain"

Possibly related to #2665; but reindexing solr with curl http://localhost:8080/api/admin/index doesn't change the error.

[pdurbin]

#2551 about a preview mode for loading tsv files is highly related. So is #3168 about documenting the tsv format in the first place. 😄

[pameyer]

Additional troubleshooting (and hints from #3168, and the linked google doc) suggest that this is due to solr schema not being updated. set advancedSearchField,facetable (and all other fields) to FALSE; retry shows same behavior. solr docs (https://cwiki.apache.org/confluence/display/solr/Schema+API#SchemaAPI-AddaDynamicFieldRule) list an API endpoint for adding fields to schema; returns 405 (probably added after solr 4.6.0 - current version is 6.4.1; unclear when new endpoint was added).

Closing this issue (root cause of problem not related to tsv API endpoint); will investigate other options (1. generate tsv/schema from same representation, 2. solr 4.6.0 -> 6.4.1 upgrade).