Try to fix datadir

CMakeLists.txt

@@ -189,8 +189,11 @@ ELSE()
 ENDIF()
 
 SET(DEFAULT_BASEDIR "${DEFAULT_MYSQL_HOME}")
-SET(MYSQL_DATADIR "${DEFAULT_MYSQL_HOME}/${INSTALL_MYSQLDATADIR}" CACHE PATH 
-  "default MySQL data directory")
+IF(INSTALL_MYSQLDATADIR MATCHES "^/.*")
+  SET(MYSQL_DATADIR ${INSTALL_MYSQLDATADIR} CACHE PATH "default MySQL data directory")
+ELSE()
+  SET(MYSQL_DATADIR "${DEFAULT_MYSQL_HOME}/${INSTALL_MYSQLDATADIR}" CACHE PATH "default MySQL data directory")
+ENDIF()
 SET(DEFAULT_CHARSET_HOME "${DEFAULT_MYSQL_HOME}")
 SET(PLUGINDIR "${DEFAULT_MYSQL_HOME}/${INSTALL_PLUGINDIR}")
 IF(SYSCONFDIR)

cmake/install_layout.cmake

@@ -125,7 +125,7 @@ SET(INSTALL_SHAREDIR_RPM            "share")
 #SET(INSTALL_DOCREADMEDIR_RPM       "${INSTALL_DOCDIR_RPM}")
 SET(INSTALL_INFODIR_RPM             "${INSTALL_SHAREDIR_RPM}/info")
 SET(INSTALL_MANDIR_RPM              "${INSTALL_SHAREDIR_RPM}/man")
-SET(INSTALL_MYSQLDATADIR_RPM        "var")
+SET(INSTALL_MYSQLDATADIR_RPM        "/var/lib/mysql")
 SET(INSTALL_MYSQLSHAREDIR_RPM       "${INSTALL_SHAREDIR_RPM}/mysql")
 SET(INSTALL_MYSQLTESTDIR_RPM        "${INSTALL_SHAREDIR_RPM}/mysql-test")
 SET(INSTALL_PLUGINDIR_RPM           "${INSTALL_LIBDIR_RPM}/mysql/plugin")
@@ -167,7 +167,7 @@ SET(INSTALL_MYSQLTESTDIR_SVR4 "mysql-test")
 SET(INSTALL_SQLBENCHROOTDIR_SVR4 ".")
 SET(INSTALL_DOCREADMEDIR_SVR4 ".")
 SET(INSTALL_SUPPORTFILESDIR_SVR4 "support-files")
-SET(MYSQL_DATADIR "/var/lib/mysql")
+SET(INSTALL_MYSQLDATADIR_RPM "/var/lib/mysql")
 
 # Clear cached variables if install layout was changed
 IF(OLD_INSTALL_LAYOUT)