Linux installer (issue #300): Install/Uninstall scripts updated

to handle the case where another systemwide installation is deployed to a different directory than the one that we are trying to install/uninstall.

installers/posix/setup.body

@@ -114,11 +114,21 @@ SELF_FILENAME=$(basename $0)
 #        if there is an Oolite installation in any
 #        user home directory.
 
-# Uninstall if possible the system-wide installation
-${INSTALL_ROOT_SYSTEMWIDE}/${OOLITE_ROOT_NAME}/uninstall 2> /dev/null
-if [ $? -eq ${ERROR_CODE_UNINSTALL_FAILED} ]
+# Uninstall, if possible, the current active system-wide installation
+if [ ${USER_IS_ROOT} ]
 then
-  exit ${ERROR_CODE_UNINSTALL_FAILED}
+  OOLITE_SHORTCUT=${STARTUP_SCRIPTS_PATH}/oolite${TRUNK}
+  if [ -e ${OOLITE_SHORTCUT} ]
+  then
+    INSTALL_ROOT_SYSTEMWIDE_ACTIVE=`cat ${OOLITE_SHORTCUT} | head -2 | tail -1`
+    INSTALL_ROOT_SYSTEMWIDE_ACTIVE=${INSTALL_ROOT_SYSTEMWIDE_ACTIVE%%/Oolite*}
+    
+    ${INSTALL_ROOT_SYSTEMWIDE_ACTIVE}/${OOLITE_ROOT_NAME}/uninstall 2> /dev/null
+    if [ $? -eq ${ERROR_CODE_UNINSTALL_FAILED} ]
+    then
+      exit ${ERROR_CODE_UNINSTALL_FAILED}
+    fi
+  fi
 fi
 
 # Uninstall user's instalation

installers/posix/uninstall.source

@@ -74,6 +74,23 @@ else
   fi
 fi
 
+# Check if this is not the active Oolite systemwide installation
+if [ ${USER_IS_ROOT} ] 
+then
+  OOLITE_SHORTCUT=${STARTUP_SCRIPTS_PATH}/oolite${TRUNK} 
+  if [ -e ${OOLITE_SHORTCUT} ]
+  then
+    INSTALL_ROOT_SYSTEMWIDE_ACTIVE=`cat ${OOLITE_SHORTCUT} | head -2 | tail -1`
+    INSTALL_ROOT_SYSTEMWIDE_ACTIVE=${INSTALL_ROOT_SYSTEMWIDE_ACTIVE%%/Oolite*}
+    if [ "${INSTALL_ROOT_SYSTEMWIDE}" != "${INSTALL_ROOT_SYSTEMWIDE_ACTIVE}" ] 
+    then
+      echo
+      echo "Error: The Oolite${TRUNK} startup scripts indicate another systemwide installation is active. Automatic uninstall will now exit to avoid impairing the active installation." 
+      exit ${ERROR_CODE_UNINSTALL_FAILED} 
+    fi 
+  fi 
+fi 
+
 
 # Remove Oolite