Fix NFS exports pruning of other users. Issue 9070.

Author: kotsis

lib/vagrant/util/string_block_editor.rb

@@ -45,6 +45,16 @@ def keys
         end
       end
 
+      # This returns the keys (or ids) that are in the string regarding current user only (fix for issue 9070).
+      #
+      # @return [<Array<String>]
+      def cur_user_keys
+        regexp = /^#\s*VAGRANT-BEGIN:\s*(#{Process.uid}\s.+?)$\r?\n?(.*)$\r?\n?^#\s*VAGRANT-END:\s(\1)$/m
+        @value.scan(regexp).map do |match|
+          match[0]
+        end
+      end
+
       # This deletes the block with the given key if it exists.
       def delete(key)
         key    = Regexp.quote(key)

plugins/hosts/linux/cap/nfs.rb

@@ -117,7 +117,10 @@ def self.nfs_prune(environment, ui, valid_ids)
           composite_ids = valid_ids.map do |v_id|
             "#{user} #{v_id}"
           end
-          remove_ids = editor.keys - composite_ids
+
+          #Fix for issue 9070, pruning other users' NFS exports
+          #remove_ids = editor.keys - composite_ids
+          remove_ids = editor.cur_user_keys - composite_ids
 
           logger.debug("Known valid NFS export IDs: #{valid_ids}")
           logger.debug("Composite valid NFS export IDs with user: #{composite_ids}")