Index: app/helpers/queries_helper.rb
===================================================================
--- app/helpers/queries_helper.rb	(revision 2552)
+++ app/helpers/queries_helper.rb	(working copy)
@@ -30,7 +30,7 @@
   def column_content(column, issue)
     if column.is_a?(QueryCustomFieldColumn)
       cv = issue.custom_values.detect {|v| v.custom_field_id == column.custom_field.id}
-      show_value(cv)
+      show_value_plain(cv)
     else
       value = issue.send(column.name)
       if value.is_a?(Date)
Index: app/helpers/timelog_helper.rb
===================================================================
--- app/helpers/timelog_helper.rb	(revision 2552)
+++ app/helpers/timelog_helper.rb	(working copy)
@@ -93,7 +93,7 @@
                   entry.hours.to_s.gsub('.', decimal_separator),
                   entry.comments
                   ]
-        fields += custom_fields.collect {|f| show_value(entry.custom_value_for(f)) }
+        fields += custom_fields.collect {|f| show_value_plain(entry.custom_value_for(f)) }
                   
         csv << fields.collect {|c| begin; ic.iconv(c.to_s); rescue; c.to_s; end }
       end
Index: app/helpers/custom_fields_helper.rb
===================================================================
--- app/helpers/custom_fields_helper.rb	(revision 2552)
+++ app/helpers/custom_fields_helper.rb	(working copy)
@@ -61,12 +61,34 @@
   def custom_field_tag_with_label(name, custom_value)
     custom_field_label_tag(name, custom_value) + custom_field_tag(name, custom_value)
   end
+  
+  # Return a clean URL for a given custom field value
+  def url_format(custom_value)
+    url = custom_value.custom_field.url.strip
+    return false unless url.length > 0
 
-  # Return a string used to display a custom value
+    formatted_value = format_value(custom_value.value, custom_value.custom_field.field_format)
+    while (url.sub!(/__VALUE__/, h(formatted_value.strip)))
+    end
+    return url
+  end
+
+  # Return a formatted string used to display a custom value (including link if URL defined on custom_field)
   def show_value(custom_value)
     return "" unless custom_value
-    format_value(custom_value.value, custom_value.custom_field.field_format)
+    formatted_value = format_value(custom_value.value, custom_value.custom_field.field_format)
+    if (value = url_format(custom_value))
+      return link_to formatted_value, value, :target=>'_blank'
+    else
+      return h(format_value(custom_value.value, custom_value.custom_field.field_format))
+    end
   end
+
+  # Return an escaped string used to display a custom value
+  def show_value_plain(custom_value)
+    return "" unless custom_value
+    return h(format_value(custom_value.value, custom_value.custom_field.field_format))
+  end
   
   # Return a string used to display a custom value
   def format_value(value, field_format)
Index: app/views/custom_fields/_form.rhtml
===================================================================
--- app/views/custom_fields/_form.rhtml	(revision 2552)
+++ app/views/custom_fields/_form.rhtml	(working copy)
@@ -8,6 +8,7 @@
   p_regexp = $("custom_field_regexp");
   p_values = $("custom_field_possible_values");
   p_searchable = $("custom_field_searchable");
+  p_url = $("custom_field_url");
   p_default = $("custom_field_default_value");
   
   p_default.setAttribute('type','text');
@@ -65,6 +66,8 @@
 																																			 :rows => 15 %>
 <br /><em><%= l(:text_custom_field_possible_values_info) %></em></p>
 <p><%= @custom_field.field_format == 'bool' ? f.check_box(:default_value) : f.text_field(:default_value) %></p>
+<p><%= f.text_field :url, :size => 60 %>
+<br /><%= l(:text_custom_field_url_info) %></p>
 </div>
 
 <div class="box">
Index: app/views/mailer/_issue_text_plain.rhtml
===================================================================
--- app/views/mailer/_issue_text_plain.rhtml	(revision 2552)
+++ app/views/mailer/_issue_text_plain.rhtml	(working copy)
@@ -7,7 +7,7 @@
 <%=l(:field_assigned_to)%>: <%= issue.assigned_to %>
 <%=l(:field_category)%>: <%= issue.category %>
 <%=l(:field_fixed_version)%>: <%= issue.fixed_version %>
-<% issue.custom_values.each do |c| %><%= c.custom_field.name %>: <%= show_value(c) %>
+<% issue.custom_values.each do |c| %><%= c.custom_field.name %>: <%= show_value_plain(c) %>
 <% end %>
 
 <%= issue.description %>
Index: app/views/projects/show.rhtml
===================================================================
--- app/views/projects/show.rhtml	(revision 2552)
+++ app/views/projects/show.rhtml	(working copy)
@@ -10,7 +10,7 @@
   <% end %>
 	<% @project.custom_values.each do |custom_value| %>
 	<% if !custom_value.value.empty? %>
-	   <li><%= custom_value.custom_field.name%>: <%=h show_value(custom_value) %></li>
+	   <li><%= custom_value.custom_field.name%>: <%= show_value(custom_value) %></li>
 	<% end %>
 	<% end %>
 	</ul>	
Index: app/views/account/show.rhtml
===================================================================
--- app/views/account/show.rhtml	(revision 2552)
+++ app/views/account/show.rhtml	(working copy)
@@ -11,7 +11,7 @@
 	<% end %>
 	<% for custom_value in @custom_values %>
 	<% if !custom_value.value.empty? %>
-    <li><%= custom_value.custom_field.name%>: <%=h show_value(custom_value) %></li>
+    <li><%= custom_value.custom_field.name%>: <%= show_value(custom_value) %></li>
 	<% end %>
 	<% end %>
     <li><%=l(:label_registered_on)%>: <%= format_date(@user.created_on) %></li>
Index: app/views/issues/show.rhtml
===================================================================
--- app/views/issues/show.rhtml	(revision 2552)
+++ app/views/issues/show.rhtml	(working copy)
@@ -46,7 +46,7 @@
 <tr>
 <% n = 0 -%>
 <% @issue.custom_values.each do |value| -%>
-    <td valign="top"><b><%=h value.custom_field.name %>:</b></td><td valign="top"><%= simple_format(h(show_value(value))) %></td>
+    <td valign="top"><b><%=h value.custom_field.name %>:</b></td><td valign="top"><%= simple_format(show_value(value)) %></td>
 <% n = n + 1
    if (n > 1) 
         n = 0 %>
Index: config/locales/en.yml
===================================================================
--- config/locales/en.yml	(revision 2552)
+++ config/locales/en.yml	(working copy)
@@ -755,6 +755,7 @@
   text_repository_usernames_mapping: "Select or update the Redmine user mapped to each username found in the repository log.\nUsers with the same Redmine and repository username or email are automatically mapped."
   text_diff_truncated: '... This diff was truncated because it exceeds the maximum size that can be displayed.'
   text_custom_field_possible_values_info: 'One line for each value'
+  text_custom_field_url_info: '(__VALUE__ is a placeholder for each of the field values, eg. http://www.google.com/search?q=__VALUE__)'
   
   default_role_manager: Manager
   default_role_developper: Developer
Index: db/migrate/20090304184821_add_custom_fields_url.rb
===================================================================
--- db/migrate/20090304184821_add_custom_fields_url.rb	(revision 0)
+++ db/migrate/20090304184821_add_custom_fields_url.rb	(revision 0)
@@ -0,0 +1,9 @@
+class AddCustomFieldsUrl < ActiveRecord::Migration
+  def self.up
+    add_column :custom_fields, :url, :string, :limit=>255, :default=>"", :null=>false
+  end
+
+  def self.down
+    remove_column :custom_fields, :url
+  end
+end