Cleanup mysql_inplace_alter_table()

Removed redundant tdc_remove_table(TDC_RT_REMOVE_ALL). Share was marked
flushed by preceding wait_while_table_is_used() and eventually flushed by
close_all_tables_for_name().

Part of MDEV-17882 - Cleanup refresh version

sql/sql_table.cc

@@ -7946,10 +7946,8 @@ static bool mysql_inplace_alter_table(THD *thd,
   // Rename altered table if requested.
   if (alter_ctx->is_table_renamed())
   {
-    // Remove TABLE and TABLE_SHARE for old name from TDC.
-    tdc_remove_table(thd, TDC_RT_REMOVE_ALL,
-                     alter_ctx->db.str, alter_ctx->table_name.str);
-
+    DBUG_ASSERT(!tdc_share_is_cached(thd, alter_ctx->db.str,
+                                     alter_ctx->table_name.str));
     if (mysql_rename_table(db_type, &alter_ctx->db, &alter_ctx->table_name,
                            &alter_ctx->new_db, &alter_ctx->new_alias, 0))
     {

sql/table_cache.cc

@@ -776,6 +776,23 @@ void tdc_unlock_share(TDC_element *element)
 }
 
 
+int tdc_share_is_cached(THD *thd, const char *db, const char *table_name)
+{
+  char key[MAX_DBKEY_LENGTH];
+
+  if (unlikely(fix_thd_pins(thd)))
+    return -1;
+
+  if (lf_hash_search(&tdc_hash, thd->tdc_hash_pins, (uchar*) key,
+                     tdc_create_key(key, db, table_name)))
+  {
+    lf_hash_search_unpin(thd->tdc_hash_pins);
+    return 1;
+  }
+  return 0;
+}
+
+
 /*
   Get TABLE_SHARE for a table.
 

sql/table_cache.h

@@ -77,6 +77,7 @@ extern void tdc_purge(bool all);
 extern TDC_element *tdc_lock_share(THD *thd, const char *db,
                                    const char *table_name);
 extern void tdc_unlock_share(TDC_element *element);
+int tdc_share_is_cached(THD *thd, const char *db, const char *table_name);
 extern TABLE_SHARE *tdc_acquire_share(THD *thd, TABLE_LIST *tl, uint flags,
                                       TABLE **out_table= 0);
 extern void tdc_release_share(TABLE_SHARE *share);