Comment 6 for bug 1133093

Running without the drop at the end of the test indicates root cause is a memory leak

130812 19:23:46 [Note] /home/andrew/develop/maria/repo/oqgraph-varchar/build/sql/mysqld: ready for connections.
Version: '10.0.1-MariaDB-debug-log' socket: '/home/andrew/develop/maria/repo/oqgraph-varchar/build/mysql-test/var/tmp/mysqld.1.sock' port: 16000 Source distribution
Warning: 984 bytes lost, allocated by T@2 at mysys/my_alloc.c:233, sql/thr_malloc.cc:77, sql/field.h:163, sql/field.cc:9501, sql/table.cc:1590, sql/table.cc:747, ??:0, sql/handler.cc:2347
Warning: 1744 bytes lost, allocated by T@2 at mysys/my_alloc.c:233, sql/sql_list.h:43, myisam/ha_myisam.cc:128, sql/handler.cc:252, sql/table.cc:1370, sql/table.cc:747, ??:0, sql/handler.cc:2347
Warning: 984 bytes lost, allocated by T@2 at mysys/my_alloc.c:233, ??:0, sql/handler.cc:2347, sql/table.cc:2663, sql/sql_base.cc:3207, sql/sql_base.cc:4564, sql/sql_base.cc:5115, sql/sql_base.cc:5718
Memory lost: 3712 bytes in 2204 chunks
mysqld: /home/andrew/develop/maria/repo/oqgraph-varchar/sql/sql_class.cc:1572: virtual THD::~THD(): Assertion `status_var.memory_used == 0' failed.

I did some funky stuff in gdb and worked out that the oqgraph3::cursor has a reference count that never falls to zero:

andrew@atlantis3:~/develop/maria$ egrep '_ref_count|#2' refs1.txt | paste - -|grep cursor
163 ptr->_ref_count++; #2 0x00000000009a5e9c in oqgraph3::cursor::cursor (this=0x22c3f10, graph=...) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:69
163 ptr->_ref_count++; #2 0x00000000009a5e9c in oqgraph3::cursor::cursor (this=0x22c4130, graph=...) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:69
163 ptr->_ref_count++; #2 0x00000000009a5e9c in oqgraph3::cursor::cursor (this=0x22d6de0, graph=...) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:69
163 ptr->_ref_count++; #2 0x00000000009a5e9c in oqgraph3::cursor::cursor (this=0x22d6eb0, graph=...) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:69
163 ptr->_ref_count++; #2 0x00000000009a5e9c in oqgraph3::cursor::cursor (this=0x22d7670, graph=...) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:69
163 ptr->_ref_count++; #2 0x00000000009a5e9c in oqgraph3::cursor::cursor (this=0x22d7740, graph=...) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:69
168 ptr->_ref_count--; #2 0x00000000009a659f in oqgraph3::cursor::~cursor (this=0x22d6eb0, __in_chrg=<optimized out>) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:93
168 ptr->_ref_count--; #2 0x00000000009a659f in oqgraph3::cursor::~cursor (this=0x22d6de0, __in_chrg=<optimized out>) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:93
163 ptr->_ref_count++; #2 0x00000000009a5e9c in oqgraph3::cursor::cursor (this=0x22d7020, graph=...) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:69
163 ptr->_ref_count++; #2 0x00000000009a5e9c in oqgraph3::cursor::cursor (this=0x22d6d80, graph=...) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:69
168 ptr->_ref_count--; #2 0x00000000009a659f in oqgraph3::cursor::~cursor (this=0x22d7020, __in_chrg=<optimized out>) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:93
168 ptr->_ref_count--; #2 0x00000000009a659f in oqgraph3::cursor::~cursor (this=0x22d7670, __in_chrg=<optimized out>) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:93
168 ptr->_ref_count--; #2 0x00000000009a659f in oqgraph3::cursor::~cursor (this=0x22d7740, __in_chrg=<optimized out>) at /home/andrew/develop/maria/repo/oqgraph-varchar/storage/oqgraph/oqgraph_thunk.cc:93

This was also visible in the debugger at the assertion point - _ref_count=3