plugin session local variable not reset at plugin reinstall

# Install the example engine (declares example.int_var)

INSTALL PLUGIN example SONAME 'ha_example.so';

# Registered default

SELECT @@session.example_int_var AS first_install_default;

first_install_default

0

# Set a per-session value on THIS connection (max of the -1..1 range)

SET SESSION example_int_var = 1;

SELECT @@session.example_int_var AS after_set;

after_set

1

# Also move the GLOBAL off its registered default (0) to a distinct value

# (-1), so a post-reinstall read can tell "reset to default" (0) from

# "stale value survived" (-1)

SET GLOBAL example_int_var = -1;

SELECT @@global.example_int_var AS global_after_set;

global_after_set

-1

UNINSTALL PLUGIN example;

# Read the session var while the plugin is uninstalled

SELECT @@session.example_int_var AS when_uninstalled;

ERROR HY000: Unknown system variable 'example_int_var'

# Reinstall on the SAME connection/server; session value MUST be default

# again.

INSTALL PLUGIN example SONAME 'ha_example.so';

SELECT @@session.example_int_var AS after_reinstall;

after_reinstall

1

SELECT @@global.example_int_var AS after_reinstall_global;

after_reinstall_global

0

UNINSTALL PLUGIN example;