Created unit test for #325

[pmconrad]

This test, without BM's fix, reproduces the crash from 2017-07-10.

[oxarbitrage]

Hi Peter, i tested your test unit and it is working as expected.

for the record here is some output. i created 2 installations folders, one with bytemaster patch and the other without it. test unit of this pull request added to both versions.

running test in the version with patch:

root@NC-PH-1346-07:~/bitshares/pull326/1/bitshares-core/tests# ./chain_test -t database_tests
Random number generator seeded to 1499943969
GRAPHENE_TESTING_GENESIS_TIMESTAMP is 1431700000
Running 2 test cases...
369177ms th_a       object_database.cpp:94        open                 ] Opening object database from /tmp/graphene-tmp/fb09-7134-be6d-dd2e ...
369177ms th_a       object_database.cpp:100       open                 ] Done opening object database.
369179ms th_a       db_management.cpp:170         close                ] Database close unexpected exception: {"code":10,"name":"assert_exception","message":"Ass
ert Exception","stack":[{"context":{"level":"error","file":"fork_database.cpp","line":41,"method":"pop_block","hostname":"","thread_name":"th_a","timestamp":"201
7-07-13T11:06:09"},"format":"_head: no blocks to pop","data":{}},{"context":{"level":"warn","file":"db_block.cpp","line":431,"method":"pop_block","hostname":"","
thread_name":"th_a","timestamp":"2017-07-13T11:06:09"},"format":"","data":{}}]}
369198ms th_a       db_management.cpp:170         close                ] Database close unexpected exception: {"code":3070001,"name":"pop_empty_chain","message":
"there are no blocks to pop","stack":[{"context":{"level":"error","file":"db_block.cpp","line":423,"method":"pop_block","hostname":"","thread_name":"th_a","times
tamp":"2017-07-13T11:06:09"},"format":"there are no blocks to pop","data":{}},{"context":{"level":"warn","file":"db_block.cpp","line":431,"method":"pop_block","h
ostname":"","thread_name":"th_a","timestamp":"2017-07-13T11:06:09"},"format":"","data":{}}]}
369214ms th_a       object_database.cpp:94        open                 ] Opening object database from /tmp/graphene-tmp/b861-0359-0fa6-a0e8 ...
369214ms th_a       object_database.cpp:100       open                 ] Done opening object database.
369218ms th_a       db_management.cpp:170         close                ] Database close unexpected exception: {"code":10,"name":"assert_exception","message":"Ass
ert Exception","stack":[{"context":{"level":"error","file":"fork_database.cpp","line":41,"method":"pop_block","hostname":"","thread_name":"th_a","timestamp":"201
7-07-13T11:06:09"},"format":"_head: no blocks to pop","data":{}},{"context":{"level":"warn","file":"db_block.cpp","line":431,"method":"pop_block","hostname":"","
thread_name":"th_a","timestamp":"2017-07-13T11:06:09"},"format":"","data":{}}]}
369252ms th_a       db_management.cpp:170         close                ] Database close unexpected exception: {"code":3070001,"name":"pop_empty_chain","message":
"there are no blocks to pop","stack":[{"context":{"level":"error","file":"db_block.cpp","line":423,"method":"pop_block","hostname":"","thread_name":"th_a","times
tamp":"2017-07-13T11:06:09"},"format":"there are no blocks to pop","data":{}},{"context":{"level":"warn","file":"db_block.cpp","line":431,"method":"pop_block","h
ostname":"","thread_name":"th_a","timestamp":"2017-07-13T11:06:09"},"format":"","data":{}}]}

*** No errors detected
root@NC-PH-1346-07:~/bitshares/pull326/1/bitshares-core/tests#

test output in the version without patch:

root@NC-PH-1346-07:~/bitshares/pull326/2/bitshares-core/tests# ./chain_test -t database_tests
Random number generator seeded to 1499944254
GRAPHENE_TESTING_GENESIS_TIMESTAMP is 1431700000
Running 2 test cases...

654697ms th_a       object_database.cpp:94        open                 ] Opening object database from /tmp/graphene-tmp/ade1-a78c-cd06-cc7f ...
654697ms th_a       object_database.cpp:100       open                 ] Done opening object database.
654699ms th_a       db_management.cpp:170         close                ] Database close unexpected exception: {"code":10,"name":"assert_exception","message":"Ass
ert Exception","stack":[{"context":{"level":"error","file":"fork_database.cpp","line":41,"method":"pop_block","hostname":"","thread_name":"th_a","timestamp":"201
7-07-13T11:10:54"},"format":"_head: no blocks to pop","data":{}},{"context":{"level":"warn","file":"db_block.cpp","line":431,"method":"pop_block","hostname":"","
thread_name":"th_a","timestamp":"2017-07-13T11:10:54"},"format":"","data":{}}]}
654717ms th_a       db_management.cpp:170         close                ] Database close unexpected exception: {"code":3070001,"name":"pop_empty_chain","message":
"there are no blocks to pop","stack":[{"context":{"level":"error","file":"db_block.cpp","line":423,"method":"pop_block","hostname":"","thread_name":"th_a","times
tamp":"2017-07-13T11:10:54"},"format":"there are no blocks to pop","data":{}},{"context":{"level":"warn","file":"db_block.cpp","line":431,"method":"pop_block","h
ostname":"","thread_name":"th_a","timestamp":"2017-07-13T11:10:54"},"format":"","data":{}}]}
654733ms th_a       object_database.cpp:94        open                 ] Opening object database from /tmp/graphene-tmp/97fb-c05c-0a85-1f91 ...
654733ms th_a       object_database.cpp:100       open                 ] Done opening object database.
unknown location(0): fatal error in "flat_index_test": memory access violation at address: 0x00000008: no mapping at fault address
/root/bitshares/pull326/2/bitshares-core/tests/common/database_fixture.cpp(214): last checkpoint

*** 1 failure detected in test suite "Master Test Suite"
root@NC-PH-1346-07:~/bitshares/pull326/2/bitshares-core/tests#