MDEV-27607: mysql_install_db to install mysql_upgrade_info

For compatibility this is under an extra option --upgrade-info

The goal here is to install a data directory with the required
info to let mysql_upgrade know that an upgrade isn't required.

debian/mariadb-server-10.2.postinst

@@ -144,7 +144,7 @@ EOF
     # Debian: beware of the bashisms...
     # Debian: can safely run on upgrades with existing databases
     set +e
-    bash /usr/bin/mysql_install_db --rpm --cross-bootstrap --user=mysql --disable-log-bin 2>&1 | $ERR_LOGGER
+    bash /usr/bin/mysql_install_db --rpm --cross-bootstrap --user=mysql --disable-log-bin --upgrade-info 2>&1 | $ERR_LOGGER
     set -e
 
     ## On every reconfiguration the maintenance user is recreated.

man/mysql_install_db.1

@@ -276,6 +276,21 @@ This must be given as the first argument\&.
 .sp -1
 .IP \(bu 2.3
 .\}
+.\" mysql_install_db: upgrade-info option
+.\" upgrade-info option: mysql_install_db
+\fB\-\-upgrade\-info\fR
+.sp
+This places a mysql_upgrade_info file containing the server version in the data directory\&.
+.RE
+.sp
+.RS 4
+.ie n \{\
+\h'-04'\(bu\h'+03'\c
+.\}
+.el \{\
+.sp -1
+.IP \(bu 2.3
+.\}
 .\" mysql_install_db: rpm option
 .\" rpm option: mysql_install_db
 \fB\-\-rpm\fR

scripts/mysql_install_db.sh

@@ -41,6 +41,7 @@ create database if not exists test;
 use mysql;"
 auth_root_authentication_method=normal
 auth_root_socket_user='root'
+upgrade_info=0
 
 dirname0=`dirname $0 2>/dev/null`
 dirname0=`dirname $dirname0 2>/dev/null`
@@ -97,6 +98,7 @@ Usage: $0 [OPTIONS]
                        user.  You must be root to use this option.  By default
                        mysqld runs using your current login name and files and
                        directories that it creates will be owned by you.
+  --upgrade-info       Store mysql_upgrade_info in the installed data directory.
 
 All other options are passed to the mysqld program
 
@@ -152,6 +154,7 @@ parse_arguments()
       --skip-name-resolve) ip_only=1 ;;
       --verbose) verbose=1 ; silent_startup="" ;;
       --rpm) in_rpm=1 ;;
+      --upgrade-info) upgrade_info=1 ;;
       --help) usage ;;
       --no-defaults|--defaults-file=*|--defaults-extra-file=*)
         defaults="$arg" ;;
@@ -509,6 +512,10 @@ SET @auth_root_socket='$auth_root_socket_user';" ;;
 esac
 if { echo "$install_params"; cat "$create_system_tables" "$create_system_tables2" "$fill_system_tables" "$fill_help_tables" "$maria_add_gis_sp"; } | eval "$filter_cmd_line" | mysqld_install_cmd_line > /dev/null
 then
+  if test "$upgrade_info" -eq 1
+  then
+    printf "@VERSION@-MariaDB" > "$ldata/mysql_upgrade_info"
+  fi
   s_echo "OK"
 else
   echo