*** portupgrade.orig	2018-04-24 15:55:20.997322000 +0200
--- portupgrade	2018-04-24 16:42:52.064426000 +0200
***************
*** 199,204 ****
--- 199,205 ----
    $logfilename_format = nil
    $make_args = ""
    $make_env = []
+   $flavor = ""
    $new = MYNAME == 'portinstall'
    $noexecute = false
    $noconfig = false
***************
*** 1179,1184 ****
--- 1180,1189 ----
      make_env << 'env'
    end
  
+   unless $flavor.empty?
+      make_env << 'FLAVOR=' + $flavor
+   end
+ 
    unless is_new or $without_env_upgrade
      make_env.concat(get_upgrade_env_vars($current_pkgname))
    end
***************
*** 1264,1269 ****
--- 1269,1286 ----
  
    oldpkgname = oldpkg.fullname
    origin ||= oldpkg.origin
+ # old flavor
+   $flavor = backquote!(PkgDB::command(:pkg), 'annotate', '-Sq', "#{oldpkgname}", 'flavor').chomp
+ # new flavor
+   portdir = $portsdb.portdir(origin)
+   newflavor = `cd #{portdir} && make pretty-flavors-package-names | sed -ne 's!^\\([A-Za-z0-9_]*\\): *#{oldpkgname}$!\\1!p'`
+   newflavor.chomp!
+   if $flavor.empty? and !newflavor.empty?
+ 	$flavor = newflavor
+   	progress_message "adding flavor #{oldpkgname} #{$flavor}" unless $flavor.empty?
+   else
+   	progress_message "preserving flavor #{oldpkgname} #{$flavor}" unless $flavor.empty?
+   end
  
    if origin && config_held?(origin)
      if $force