MDEV-21499 Merge new release of InnoDB 5.7.29 to 10.2

storage/innobase/include/univ.i

 /*****************************************************************************
 
 Copyright (c) 1994, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2013, 2019, MariaDB Corporation.
+Copyright (c) 2013, 2020, MariaDB Corporation.
 Copyright (c) 2008, Google Inc.
 
 Portions of this file contain modifications contributed and copyrighted by
@@ -41,7 +41,7 @@ Created 1/20/1994 Heikki Tuuri
 
 #define INNODB_VERSION_MAJOR	5
 #define INNODB_VERSION_MINOR	7
-#define INNODB_VERSION_BUGFIX	28
+#define INNODB_VERSION_BUGFIX	29
 
 /* The following is the InnoDB version as shown in
 SELECT plugin_version FROM information_schema.plugins;

storage/innobase/os/os0file.cc

 /***********************************************************************
 
-Copyright (c) 1995, 2017, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 1995, 2019, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2009, Percona Inc.
-Copyright (c) 2013, 2019, MariaDB Corporation.
+Copyright (c) 2013, 2020, MariaDB Corporation.
 
 Portions of this file contain modifications contributed and copyrighted
 by Percona Inc.. Those modifications are
@@ -1474,6 +1474,12 @@ os_file_get_parent_dir(
 		return(NULL);
 	}
 
+	if (last_slash - path < 0) {
+		/* Sanity check, it prevents gcc from trying to handle this case which
+		 * results in warnings for some optimized builds */
+		return (NULL);
+	}
+
 	/* Non-trivial directory component */
 
 	return(mem_strdupl(path, last_slash - path));