HashSpdb Fails the DBMemTableTest.InsertWithHint unit test (db_memtable_test.cc)

[udi-speedb]

After modifying this unit test to run its applicable tests on HashSpdb, in addition to SkipList, this unit test fails:

udi@udi-speedb:~/speedb-oss$ ./db_memtable_test 
[==========] Running 8 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 8 tests from DBMemTableTest/DBMemTableTest
[ RUN      ] DBMemTableTest/DBMemTableTest.DuplicateSeq/0
[       OK ] DBMemTableTest/DBMemTableTest.DuplicateSeq/0 (62 ms)
[ RUN      ] DBMemTableTest/DBMemTableTest.DuplicateSeq/1
[       OK ] DBMemTableTest/DBMemTableTest.DuplicateSeq/1 (348 ms)
[ RUN      ] DBMemTableTest/DBMemTableTest.ConcurrentMergeWrite/0
[       OK ] DBMemTableTest/DBMemTableTest.ConcurrentMergeWrite/0 (30 ms)
[ RUN      ] DBMemTableTest/DBMemTableTest.ConcurrentMergeWrite/1
[       OK ] DBMemTableTest/DBMemTableTest.ConcurrentMergeWrite/1 (136 ms)
[ RUN      ] DBMemTableTest/DBMemTableTest.InsertWithHint/0
[       OK ] DBMemTableTest/DBMemTableTest.InsertWithHint/0 (41 ms)
[ RUN      ] DBMemTableTest/DBMemTableTest.InsertWithHint/1
db/db_memtable_test.cc:329: Failure
Expected: (hint_foo) != (hint_bar), actual: NULL vs NULL
[  FAILED  ] DBMemTableTest/DBMemTableTest.InsertWithHint/1, where GetParam() = "hash_spdb" (159 ms)
[ RUN      ] DBMemTableTest/DBMemTableTest.ColumnFamilyId/0
[       OK ] DBMemTableTest/DBMemTableTest.ColumnFamilyId/0 (55 ms)
[ RUN      ] DBMemTableTest/DBMemTableTest.ColumnFamilyId/1
[       OK ] DBMemTableTest/DBMemTableTest.ColumnFamilyId/1 (676 ms)
[----------] 8 tests from DBMemTableTest/DBMemTableTest (1508 ms total)

[----------] Global test environment tear-down
[==========] 8 tests from 1 test case ran. (1508 ms total)
[  PASSED  ] 7 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] DBMemTableTest/DBMemTableTest.InsertWithHint/1, where GetParam() = "hash_spdb"