Index: app/helpers/issues_helper.rb
===================================================================
--- app/helpers/issues_helper.rb	(revision 12960)
+++ app/helpers/issues_helper.rb	(working copy)
@@ -234,7 +234,7 @@
   def email_issue_attributes(issue, user)
     items = []
     %w(author status priority assigned_to category fixed_version).each do |attribute|
-      unless issue.disabled_core_fields.include?(attribute+"_id")
+      unless issue.disabled_core_fields.include?(attribute+"_id") or issue.hidden_attribute_names(user).include?(attribute+"_id")
         items << "#{l("field_#{attribute}")}: #{issue.send attribute}"
       end
     end
@@ -241,6 +241,7 @@
     issue.visible_custom_field_values(user).each do |value|
       items << "#{value.custom_field.name}: #{show_value(value)}"
     end
+    
     items
   end
 
@@ -260,30 +261,34 @@
     strings = []
     values_by_field = {}
     details.each do |detail|
-      if detail.property == 'cf'
-        field = detail.custom_field
-        if field && field.multiple?
-          values_by_field[field] ||= {:added => [], :deleted => []}
-          if detail.old_value
-            values_by_field[field][:deleted] << detail.old_value
+      unless (detail.property == 'cf' || detail.property == 'attr') &&  detail.journal.issue.hidden_attribute?(detail.prop_key, options[:user])
+        if detail.property == 'cf'
+          field = detail.custom_field
+          if field && field.multiple?
+            values_by_field[field] ||= {:added => [], :deleted => []}
+            if detail.old_value
+              values_by_field[field][:deleted] << detail.old_value
+            end
+            if detail.value
+              values_by_field[field][:added] << detail.value
+            end
+            next
           end
-          if detail.value
-            values_by_field[field][:added] << detail.value
-          end
-          next
         end
+        strings << show_detail(detail, no_html, options)
       end
-      strings << show_detail(detail, no_html, options)
     end
     values_by_field.each do |field, changes|
       detail = JournalDetail.new(:property => 'cf', :prop_key => field.id.to_s)
-      detail.instance_variable_set "@custom_field", field
-      if changes[:added].any?
-        detail.value = changes[:added]
-        strings << show_detail(detail, no_html, options)
-      elsif changes[:deleted].any?
-        detail.old_value = changes[:deleted]
-        strings << show_detail(detail, no_html, options)
+      unless detail.journal.issue.hidden_attribute?(detail.prop_key, options[:user])
+        detail.instance_variable_set "@custom_field", field
+        if changes[:added].any?
+          detail.value = changes[:added]
+          strings << show_detail(detail, no_html, options)
+        elsif changes[:deleted].any?
+          detail.old_value = changes[:deleted]
+          strings << show_detail(detail, no_html, options)
+        end
       end
     end
     strings
Index: app/helpers/workflows_helper.rb
===================================================================
--- app/helpers/workflows_helper.rb	(revision 12960)
+++ app/helpers/workflows_helper.rb	(working copy)
@@ -25,6 +25,7 @@
   def field_permission_tag(permissions, status, field, role)
     name = field.is_a?(CustomField) ? field.id.to_s : field
     options = [["", ""], [l(:label_readonly), "readonly"]]
+    options << [l(:label_hidden), "hidden"]
     options << [l(:label_required), "required"] unless field_required?(field)
     html_options = {}
     selected = permissions[status.id][name]
Index: app/models/issue.rb
===================================================================
--- app/models/issue.rb	(revision 12960)
+++ app/models/issue.rb	(working copy)
@@ -205,9 +205,11 @@
 
   def visible_custom_field_values(user=nil)
     user_real = user || User.current
-    custom_field_values.select do |value|
+    fields = custom_field_values.select do |value|
       value.custom_field.visible_by?(project, user_real)
     end
+    fields = fields & viewable_custom_field_values(user_real)
+    fields
   end
 
   # Copies attributes from another issue, arg can be an id or an Issue
@@ -482,6 +484,14 @@
       read_only_attribute_names(user).include?(value.custom_field_id.to_s)
     end
   end
+  
+  # Returns the custom_field_values that can be viewed by the given user
+  # For now: just exclude Fix Info and RNs, as it is printed seperately below description.
+  def viewable_custom_field_values(user=nil)
+    custom_field_values.reject do |value|
+      hidden_attribute_names(user).include?(value.custom_field_id.to_s)
+    end
+  end  
 
   # Returns the names of attributes that are read-only for user or the current user
   # For users with multiple roles, the read-only fields are the intersection of
@@ -492,8 +502,13 @@
   #   issue.read_only_attribute_names # => ['due_date', '2']
   #   issue.read_only_attribute_names(user) # => []
   def read_only_attribute_names(user=nil)
-    workflow_rule_by_attribute(user).reject {|attr, rule| rule != 'readonly'}.keys
+    workflow_rule_by_attribute(user).reject {|attr, rule| rule != 'readonly' and rule != 'hidden'}.keys
   end
+  
+  # Same as above, but for hidden fields
+  def hidden_attribute_names(user=nil)
+    workflow_rule_by_attribute(user).reject {|attr, rule| rule != 'hidden'}.keys
+  end
 
   # Returns the names of required attributes for user or the current user
   # For users with multiple roles, the required fields are the intersection of
@@ -506,6 +521,11 @@
   def required_attribute_names(user=nil)
     workflow_rule_by_attribute(user).reject {|attr, rule| rule != 'required'}.keys
   end
+  
+  # Returns true if the attribute should be hidden for user
+  def hidden_attribute?(name, user=nil)
+    hidden_attribute_names(user).include?(name.to_s)
+  end  
 
   # Returns true if the attribute is required for user
   def required_attribute?(name, user=nil)
@@ -813,19 +833,20 @@
     notified_users.collect(&:mail)
   end
 
-  def each_notification(users, &block)
+  def each_notification(users, &block)   
     if users.any?
-      if custom_field_values.detect {|value| !value.custom_field.visible?}
-        users_by_custom_field_visibility = users.group_by do |user|
-          visible_custom_field_values(user).map(&:custom_field_id).sort
-        end
-        users_by_custom_field_visibility.values.each do |users|
-          yield(users)
-        end
-      else
-        yield(users)
+      variations = users.collect {
+        |user| (hidden_attribute_names(user) + (custom_field_values - visible_custom_field_values(user))).uniq
+      }.uniq
+      recipient_groups = Array.new(variations.count) { Array.new }
+      users.each do |user|
+        recipient_groups[variations.index(hidden_attribute_names(user))] << user
       end
-    end
+
+      recipient_groups.each do |group|
+        yield(group)
+      end
+    end    
   end
 
   # Returns the number of hours spent on this issue
Index: app/models/issue_query.rb
===================================================================
--- app/models/issue_query.rb	(revision 12960)
+++ app/models/issue_query.rb	(working copy)
@@ -248,10 +256,23 @@
   def available_columns
     return @available_columns if @available_columns
     @available_columns = self.class.available_columns.dup
+    
+    if project == nil
+      hidden_fields = []
+      all_projects.each { |prj| 
+        if prj.visible? and User.current.roles_for_project(prj).count > 0
+          hidden_fields = hidden_fields == [] ? prj.completely_hidden_attribute_names : hidden_fields & prj.completely_hidden_attribute_names
+        end
+      }
+    else
+      hidden_fields = project.completely_hidden_attribute_names
+    end
+    hidden_fields.map! {|field| field.sub(/_id$/, '')}       
+    
     @available_columns += (project ?
                             project.all_issue_custom_fields :
                             IssueCustomField
-                           ).visible.collect {|cf| QueryCustomFieldColumn.new(cf) }
+                           ).visible.collect {|cf| QueryCustomFieldColumn.new(cf) }.reject{|column| hidden_fields.include?(column.custom_field.id.to_s) }
 
     if User.current.allowed_to?(:view_time_entries, project, :global => true)
       index = nil
@@ -274,6 +295,10 @@
     @available_columns.reject! {|column|
       disabled_fields.include?(column.name.to_s)
     }
+    
+    @available_columns.reject! {|column|
+      hidden_fields.include?(column.name.to_s)
+    }    
 
     @available_columns
   end
Index: app/models/journal.rb
===================================================================
--- app/models/journal.rb	(revision 12960)
+++ app/models/journal.rb	(working copy)
@@ -57,8 +57,10 @@
   # Returns journal details that are visible to user
   def visible_details(user=User.current)
     details.select do |detail|
-      if detail.property == 'cf'
-        detail.custom_field && detail.custom_field.visible_by?(project, user)
+      if detail.property == 'attr'
+        !issue.hidden_attribute?(detail.prop_key, user)
+      elsif detail.property == 'cf'
+        detail.custom_field && detail.custom_field.visible_by?(project, user) && !issue.hidden_attribute?(detail.prop_key, user)
       elsif detail.property == 'relation'
         Issue.find_by_id(detail.value || detail.old_value).try(:visible?, user)
       else
Index: app/models/project.rb
===================================================================
--- app/models/project.rb	(revision 12960)
+++ app/models/project.rb	(working copy)
@@ -151,7 +151,36 @@
   def visible?(user=User.current)
     user.allowed_to?(:view_project, self)
   end
+  
+  # Returns list of attributes that are hidden on all statuses of all trackers for +user+ or the current user.
+  def completely_hidden_attribute_names(user=nil)
+    user_real = user || User.current
+    roles = user_real.admin ? Role.all : user_real.roles_for_project(self)
+    return {} if roles.empty?
 
+    result = {}
+    workflow_permissions = WorkflowPermission.where(:tracker_id => trackers.map(&:id), :old_status_id => IssueStatus.all.map(&:id), :role_id => roles.map(&:id), :rule => 'hidden').all
+
+    if workflow_permissions.any?
+      workflow_rules = workflow_permissions.inject({}) do |h, wp|
+        h[wp.field_name] ||= []
+        h[wp.field_name] << wp.rule
+        h
+      end
+      workflow_rules.each do |attr, rules|
+        next if rules.size < (roles.size * trackers.size * IssueStatus.all.size)
+        uniq_rules = rules.uniq
+        if uniq_rules.size == 1
+          result[attr] = uniq_rules.first
+        else
+          result[attr] = 'required'
+        end
+      end
+    end
+
+    result.keys    
+  end  
+
   # Returns a SQL conditions string used to find all projects visible by the specified user.
   #
   # Examples:
Index: app/models/query.rb
===================================================================
--- app/models/query.rb	(revision 12960)
+++ app/models/query.rb	(working copy)
@@ -54,7 +54,16 @@
   end
 
   def value(object)
-    object.send name
+    if object.respond_to?(:hidden_attribute_names)
+      hidden_fields = object.hidden_attribute_names.map {|field| field.sub(/_id$/, '')}
+      if hidden_fields.include?(name.to_s)
+        ""
+      else
+        object.send name
+      end
+    else
+      object.send name
+    end    
   end
 
   def css_classes
@@ -331,6 +340,11 @@
         options[:name] ||= l(options[:label] || "field_#{field}".gsub(/_id$/, ''))
       end
     end
+    
+    hidden_fields.each {|field|
+      @available_filters.delete field
+    }    
+    
     @available_filters
   end
 
@@ -762,42 +776,68 @@
     return sql
   end
 
+  def hidden_fields
+    return @hidden_fields if @hidden_fields
+
+    if project != nil
+      @hidden_fields = project.completely_hidden_attribute_names
+    else
+      @hidden_fields = []
+      usr = User.current;
+      first = true
+      all_projects.each { |prj|
+        if prj.visible? and usr.roles_for_project(prj).count > 0
+          if first
+            @hidden_fields = prj.completely_hidden_attribute_names(usr)
+          else
+            @hidden_fields &= prj.completely_hidden_attribute_names(usr)
+          end
+          return @hidden_fields if @hidden_fields.empty?
+        end
+        first = false
+      }
+    end
+    return @hidden_fields
+  end
+
   # Adds a filter for the given custom field
   def add_custom_field_filter(field, assoc=nil)
-    case field.field_format
-    when "text"
-      options = { :type => :text }
-    when "list"
-      options = { :type => :list_optional, :values => field.possible_values }
-    when "date"
-      options = { :type => :date }
-    when "bool"
-      options = { :type => :list, :values => [[l(:general_text_yes), "1"], [l(:general_text_no), "0"]] }
-    when "int"
-      options = { :type => :integer }
-    when "float"
-      options = { :type => :float }
-    when "user", "version"
-      return unless project
-      values = field.possible_values_options(project)
-      if User.current.logged? && field.field_format == 'user'
-        values.unshift ["<< #{l(:label_me)} >>", "me"]
+    unless hidden_fields.include?(field.id.to_s)
+      case field.field_format
+      when "text"
+        options = { :type => :text }
+      when "list"
+        options = { :type => :list_optional, :values => field.possible_values }
+      when "date"
+        options = { :type => :date }
+      when "bool"
+        options = { :type => :list, :values => [[l(:general_text_yes), "1"], [l(:general_text_no), "0"]] }
+      when "int"
+        options = { :type => :integer }
+      when "float"
+        options = { :type => :float }
+      when "user", "version"
+        return unless project
+        values = field.possible_values_options(project)
+        if User.current.logged? && field.field_format == 'user'
+          values.unshift ["<< #{l(:label_me)} >>", "me"]
+        end
+        options = { :type => :list_optional, :values => values }
+      else
+        options = { :type => :string }
       end
-      options = { :type => :list_optional, :values => values }
-    else
-      options = { :type => :string }
+      filter_id = "cf_#{field.id}"
+      filter_name = field.name
+      if assoc.present?
+        filter_id = "#{assoc}.#{filter_id}"
+        filter_name = l("label_attribute_of_#{assoc}", :name => filter_name)
+      end
+      add_available_filter filter_id, options.merge({
+        :name => filter_name,
+        :format => field.field_format,
+        :field => field
+      })
     end
-    filter_id = "cf_#{field.id}"
-    filter_name = field.name
-    if assoc.present?
-      filter_id = "#{assoc}.#{filter_id}"
-      filter_name = l("label_attribute_of_#{assoc}", :name => filter_name)
-    end
-    add_available_filter filter_id, options.merge({
-      :name => filter_name,
-      :format => field.field_format,
-      :field => field
-    })
   end
 
   # Adds filters for the given custom fields scope
Index: app/models/workflow_permission.rb
===================================================================
--- app/models/workflow_permission.rb	(revision 12960)
+++ app/models/workflow_permission.rb	(working copy)
@@ -16,13 +16,13 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 class WorkflowPermission < WorkflowRule
-  validates_inclusion_of :rule, :in => %w(readonly required)
+  validates_inclusion_of :rule, :in => %w(readonly required hidden)
   validate :validate_field_name
 
   # Replaces the workflow permissions for the given tracker and role
   #
   # Example:
-  #   WorkflowPermission.replace_permissions role, tracker, {'due_date' => {'1' => 'readonly', '2' => 'required'}}
+  #   WorkflowPermission.replace_permissions role, tracker, {'due_date' => {'1' => 'readonly', '2' => 'required', '3' => 'hidden'}}
   def self.replace_permissions(tracker, role, permissions)
     destroy_all(:tracker_id => tracker.id, :role_id => role.id)
 
Index: app/views/issues/_history.html.erb
===================================================================
--- app/views/issues/_history.html.erb	(revision 12960)
+++ app/views/issues/_history.html.erb	(working copy)
@@ -1,22 +1,24 @@
 <% reply_links = authorize_for('issues', 'edit') -%>
 <% for journal in journals %>
-  <div id="change-<%= journal.id %>" class="<%= journal.css_classes %>">
-    <div id="note-<%= journal.indice %>">
-    <h4><%= link_to "##{journal.indice}", {:anchor => "note-#{journal.indice}"}, :class => "journal-link" %>
-    <%= avatar(journal.user, :size => "24") %>
-    <%= authoring journal.created_on, journal.user, :label => :label_updated_time_by %></h4>
-
-    <% if journal.details.any? %>
-    <ul class="details">
-      <% details_to_strings(journal.visible_details).each do |string| %>
-       <li><%= string %></li>
+  <% if details_to_strings(journal.details).any? || journal.notes.blank? == false %>
+    <div id="change-<%= journal.id %>" class="<%= journal.css_classes %>">
+      <div id="note-<%= journal.indice %>">
+      <h4><%= link_to "##{journal.indice}", {:anchor => "note-#{journal.indice}"}, :class => "journal-link" %>
+      <%= avatar(journal.user, :size => "24") %>
+      <%= authoring journal.created_on, journal.user, :label => :label_updated_time_by %></h4>
+  
+      <% if journal.details.any? %>
+      <ul class="details">
+        <% details_to_strings(journal.visible_details).each do |string| %>
+         <li><%= string %></li>
+        <% end %>
+      </ul>
       <% end %>
-    </ul>
-    <% end %>
-    <%= render_notes(issue, journal, :reply_links => reply_links) unless journal.notes.blank? %>
+      <%= render_notes(issue, journal, :reply_links => reply_links) unless journal.notes.blank? %>
+      </div>
     </div>
-  </div>
-  <%= call_hook(:view_issues_history_journal_bottom, { :journal => journal }) %>
+    <%= call_hook(:view_issues_history_journal_bottom, { :journal => journal }) %>
+  <% end %>
 <% end %>
 
 <% heads_for_wiki_formatter if User.current.allowed_to?(:edit_issue_notes, issue.project) || User.current.allowed_to?(:edit_own_issue_notes, issue.project) %>
Index: app/views/issues/show.html.erb
===================================================================
--- app/views/issues/show.html.erb	(revision 12960)
+++ app/views/issues/show.html.erb	(working copy)
@@ -33,29 +33,33 @@
 
 <table class="attributes">
 <%= issue_fields_rows do |rows|
-  rows.left l(:field_status), h(@issue.status.name), :class => 'status'
-  rows.left l(:field_priority), h(@issue.priority.name), :class => 'priority'
+  unless @issue.hidden_attribute?('status')
+    rows.left l(:field_status), h(@issue.status.name), :class => 'status_id'
+  end
+  unless @issue.hidden_attribute?('priority_id')
+    rows.left l(:field_priority), h(@issue.priority.name), :class => 'priority_id'
+  end  
 
-  unless @issue.disabled_core_fields.include?('assigned_to_id')
+  unless @issue.disabled_core_fields.include?('assigned_to_id') || @issue.hidden_attribute?('assigned_to_id')
     rows.left l(:field_assigned_to), avatar(@issue.assigned_to, :size => "14").to_s.html_safe + (@issue.assigned_to ? link_to_user(@issue.assigned_to) : "-"), :class => 'assigned-to'
   end
-  unless @issue.disabled_core_fields.include?('category_id')
+  unless @issue.disabled_core_fields.include?('category_id') || @issue.hidden_attribute?('category_id')
     rows.left l(:field_category), h(@issue.category ? @issue.category.name : "-"), :class => 'category'
   end
-  unless @issue.disabled_core_fields.include?('fixed_version_id')
+  unless @issue.disabled_core_fields.include?('fixed_version_id') || @issue.hidden_attribute?('fixed_version_id')
     rows.left l(:field_fixed_version), (@issue.fixed_version ? link_to_version(@issue.fixed_version) : "-"), :class => 'fixed-version'
   end
 
-  unless @issue.disabled_core_fields.include?('start_date')
+  unless @issue.disabled_core_fields.include?('start_date') || @issue.hidden_attribute?('start_date')
     rows.right l(:field_start_date), format_date(@issue.start_date), :class => 'start-date'
   end
-  unless @issue.disabled_core_fields.include?('due_date')
+  unless @issue.disabled_core_fields.include?('due_date') || @issue.hidden_attribute?('due_date')
     rows.right l(:field_due_date), format_date(@issue.due_date), :class => 'due-date'
   end
-  unless @issue.disabled_core_fields.include?('done_ratio')
+  unless @issue.disabled_core_fields.include?('done_ratio') || @issue.hidden_attribute?('done_ratio')
     rows.right l(:field_done_ratio), progress_bar(@issue.done_ratio, :width => '80px', :legend => "#{@issue.done_ratio}%"), :class => 'progress'
   end
-  unless @issue.disabled_core_fields.include?('estimated_hours')
+  unless @issue.disabled_core_fields.include?('estimated_hours') || @issue.hidden_attribute?('estimated_hours')
     unless @issue.estimated_hours.nil?
       rows.right l(:field_estimated_hours), l_hours(@issue.estimated_hours), :class => 'estimated-hours'
     end
Index: app/views/mailer/issue_edit.html.erb
===================================================================
--- app/views/mailer/issue_edit.html.erb	(revision 12960)
+++ app/views/mailer/issue_edit.html.erb	(working copy)
@@ -4,7 +4,7 @@
 <%= l(:text_issue_updated, :id => "##{@issue.id}", :author => h(@journal.user)) %>
 
 <ul>
-<% details_to_strings(@journal_details, false, :only_path => false).each do |string| %>
+<% details_to_strings(@journal_details, false, :only_path => false, :user => @auser).each do |string| %>
   <li><%= string %></li>
 <% end %>
 </ul>
Index: app/views/mailer/issue_edit.text.erb
===================================================================
--- app/views/mailer/issue_edit.text.erb	(revision 12960)
+++ app/views/mailer/issue_edit.text.erb	(working copy)
@@ -1,6 +1,6 @@
 <%= "(#{l(:field_private_notes)}) " if @journal.private_notes? -%><%= l(:text_issue_updated, :id => "##{@issue.id}", :author => @journal.user) %>
 
-<% details_to_strings(@journal_details, true).each do |string| -%>
+<% details_to_strings(@journal_details, true, :user => @auser).each do |string| -%>
 <%= string %>
 <% end -%>