Fixed bug #32034: On 64bit platforms assigning values of

storage engine system variables was not validated and
unexpected value was assigned.

The check_func_enum function used subtraction from the uint
value with the probably negative result. That result of
type uint was compared with 0 after casting to signed long
type. On architectures where long type is longer than int
type the result of comparison was unexpected.

mysql-test/r/plugin.result

@@ -17,3 +17,13 @@ UNINSTALL PLUGIN EXAMPLE;
 ERROR 42000: PLUGIN EXAMPLE does not exist
 UNINSTALL PLUGIN non_exist;
 ERROR 42000: PLUGIN non_exist does not exist
+#
+# Bug#32034: check_func_enum() does not check correct values but set it
+#            to impossible int val
+#
+INSTALL PLUGIN example SONAME 'ha_example.so';
+SET GLOBAL example_enum_var= e1;
+SET GLOBAL example_enum_var= e2;
+SET GLOBAL example_enum_var= impossible;
+ERROR 42000: Variable 'enum_var' can't be set to the value of 'impossible'
+UNINSTALL PLUGIN example;

mysql-test/t/plugin.test

@@ -24,3 +24,18 @@ UNINSTALL PLUGIN EXAMPLE;
 
 --error 1305
 UNINSTALL PLUGIN non_exist;
+
+
+--echo #
+--echo # Bug#32034: check_func_enum() does not check correct values but set it
+--echo #            to impossible int val
+--echo #
+
+INSTALL PLUGIN example SONAME 'ha_example.so';
+
+SET GLOBAL example_enum_var= e1;
+SET GLOBAL example_enum_var= e2;
+--error 1231
+SET GLOBAL example_enum_var= impossible;
+
+UNINSTALL PLUGIN example;

sql/sql_plugin.cc

@@ -1944,7 +1944,7 @@ static int check_func_enum(THD *thd, struct st_mysql_sys_var *var,
     length= sizeof(buff);
     if (!(str= value->val_str(value, buff, &length)))
       goto err;
-    if ((result= find_type(typelib, str, length, 1)-1) < 0)
+    if ((result= (long)find_type(typelib, str, length, 1)-1) < 0)
     {
       strvalue= str;
       goto err;

storage/example/ha_example.cc

@@ -848,6 +848,34 @@ int ha_example::create(const char *name, TABLE *table_arg,
 struct st_mysql_storage_engine example_storage_engine=
 { MYSQL_HANDLERTON_INTERFACE_VERSION };
 
+static ulong srv_enum_var= 0;
+
+const char *enum_var_names[]=
+{
+  "e1", "e2", NullS
+};
+
+TYPELIB enum_var_typelib=
+{
+  array_elements(enum_var_names) - 1, "enum_var_typelib",
+  enum_var_names, NULL
+};
+
+static MYSQL_SYSVAR_ENUM(
+  enum_var,                       // name
+  srv_enum_var,                   // varname
+  PLUGIN_VAR_RQCMDARG,            // opt
+  "Sample ENUM system variable.", // comment
+  NULL,                           // check
+  NULL,                           // update
+  0,                              // def
+  &enum_var_typelib);             // typelib
+
+static struct st_mysql_sys_var* example_system_variables[]= {
+  MYSQL_SYSVAR(enum_var),
+  NULL
+};
+
 mysql_declare_plugin(example)
 {
   MYSQL_STORAGE_ENGINE_PLUGIN,
@@ -860,7 +888,7 @@ mysql_declare_plugin(example)
   example_done_func,                            /* Plugin Deinit */
   0x0001 /* 0.1 */,
   NULL,                                         /* status variables */
-  NULL,                                         /* system variables */
+  example_system_variables,                     /* system variables */
   NULL                                          /* config options */
 }
 mysql_declare_plugin_end;