row0mysql.c:

  Fix performance bug: if there were thousands of tables, DROP TABLE could take as much as a second CPU time

innobase/row/row0mysql.c

@@ -1937,7 +1937,8 @@ row_drop_table_for_mysql(
 	"		found := 0;\n"
 	"	ELSE"
 	"		DELETE FROM SYS_FIELDS WHERE INDEX_ID = index_id;\n"
-	"		DELETE FROM SYS_INDEXES WHERE ID = index_id;\n"
+	"		DELETE FROM SYS_INDEXES WHERE ID = index_id\n"
+	"					 AND TABLE_ID = table_id;\n"
 	"	END IF;\n"
 	"END LOOP;\n"
 	"DELETE FROM SYS_COLUMNS WHERE TABLE_ID = table_id;\n"