LOAD DATA escaping characters causing field count violation

A character delimited file (eg. tab or comma) containing a literal \ character and a \ escape character (ie. E\\) causes inconsistent behavior between

--Server version: 10.1.18-MariaDB-1~jessie mariadb.org binary distribution

--Server version: 10.1.22-MariaDB Columnstore 1.0.8-1

when using LOAD DATA.

The value in question: E\\ (the actual value is E\), causes the MCS loader to throw an exception, complaining about a field count violation.

In 10.1.18-MariaDB the load command without specifying a FIELDS clause works fine (defaults) the string E\ gets inserted.

In 10.1.22-MariaDB Columnstore 1.0.8-1 the load command without specifying a FIELDS clause causes a field count violation. However, adding the following -empty- FIELDS clause: ESCAPED BY '', works fine and inserts the E\ string.

PS. Also inserting the string NULL is inconsistent. Non MCS requires, as we all know, the [OPTIONALLY] ENCLOSED BY to not be empty to interpret the NULL string as a NULL value. For MCS this is not necessary.