Bug#36317795 Contribution: Unified behaviour when calling plugin->deinit for all plugins

This patch unifies plugin's deinit function call to pass valid plugin pointer
instead of the nullptr for all types of plugin.

Change-Id: I482497bbaff28d5cd31d74d694056a4df6693152

Author: maras007

plugin/audit_null/audit_null.cc

@@ -251,6 +251,7 @@ static int audit_null_plugin_init(void *arg [[maybe_unused]]) {
 */
 
 static int audit_null_plugin_deinit(void *arg [[maybe_unused]]) {
+  assert(arg);
   if (g_plugin_installed == true) {
     my_free((void *)(g_record_buffer));
 

sql/handler.cc

@@ -747,7 +747,7 @@ int ha_finalize_handlerton(st_plugin_int *plugin) {
       engine plugins.
     */
     DBUG_PRINT("info", ("Deinitializing plugin: '%s'", plugin->name.str));
-    if (plugin->plugin->deinit(nullptr)) {
+    if (plugin->plugin->deinit(plugin)) {
       DBUG_PRINT("warning", ("Plugin '%s' deinit function returned error.",
                              plugin->name.str));
     }
@@ -889,7 +889,7 @@ int ha_initialize_handlerton(st_plugin_int *plugin) {
     Let plugin do its inner deinitialization as plugin->init()
     was successfully called before.
   */
-  if (plugin->plugin->deinit) (void)plugin->plugin->deinit(nullptr);
+  if (plugin->plugin->deinit) (void)plugin->plugin->deinit(plugin);
 
 err:
   my_free(hton);

sql/sql_audit.cc

@@ -767,7 +767,7 @@ static bool calc_class_mask(THD *, plugin_ref plugin, void *arg) {
 int finalize_audit_plugin(st_plugin_int *plugin) {
   unsigned long event_class_mask[MYSQL_AUDIT_CLASS_MASK_SIZE];
 
-  if (plugin->plugin->deinit && plugin->plugin->deinit(nullptr)) {
+  if (plugin->plugin->deinit && plugin->plugin->deinit(plugin)) {
     DBUG_PRINT("warning", ("Plugin '%s' deinit function returned error.",
                            plugin->name.str));
     DBUG_EXECUTE("finalize_audit_plugin", return 1;);

sql/sql_show.cc

@@ -5079,7 +5079,7 @@ int finalize_schema_table(st_plugin_int *plugin) {
   if (schema_table) {
     if (plugin->plugin->deinit) {
       DBUG_PRINT("info", ("Deinitializing plugin: '%s'", plugin->name.str));
-      if (plugin->plugin->deinit(nullptr)) {
+      if (plugin->plugin->deinit(plugin)) {
         DBUG_PRINT("warning", ("Plugin '%s' deinit function returned error.",
                                plugin->name.str));
       }

storage/example/ha_example.cc

@@ -126,6 +126,14 @@ static int example_init_func(void *p) {
   return 0;
 }
 
+static int example_deinit_func(void *p [[maybe_unused]]) {
+  DBUG_TRACE;
+
+  assert(p);
+
+  return 0;
+}
+
 /**
   @brief
   Example of simple lock controls. The "share" it creates is a
@@ -893,9 +901,9 @@ mysql_declare_plugin(example){
     PLUGIN_AUTHOR_ORACLE,
     "Example storage engine",
     PLUGIN_LICENSE_GPL,
-    example_init_func, /* Plugin Init */
-    nullptr,           /* Plugin check uninstall */
-    nullptr,           /* Plugin Deinit */
+    example_init_func,   /* Plugin Init */
+    nullptr,             /* Plugin check uninstall */
+    example_deinit_func, /* Plugin Deinit */
     0x0001 /* 0.1 */,
     func_status,              /* status variables */
     example_system_variables, /* system variables */