The innoDB global variable srv_lower_case_table_names is set to the value of lower_case_table_names declared in mysqld.h server in ha_innodb.cc.  Since this variable can change at runtime, it is reset for each handler call to ::create, ::open, ::rename_table & ::delete_table.

But it is possible for tables to be implicitly opened before an explicit handler call is made when an engine is first started or restarted.  I was able to reproduce that with the testcase in this patch on a version of InnoDB from 2 weeks ago.  It seemed like the change buffer entries for the secondary key was getting put into pages after the restart.  (But I am not sure, I did not write down the call stack while it was reproducing.)  In the current code, the implicit open, which is actually a call to dict_load_foreigns(), does not occur with this testcase.

The change is to replace srv_lower_case_table_names by an interface function in innodb.cc that retrieves the server global variable when it is needed.