diff -urN redmine-1.3.0/app/helpers/application_helper.rb redmine-1.3.0_attachments/app/helpers/application_helper.rb
--- redmine-1.3.0/app/helpers/application_helper.rb	2011-12-10 16:53:33.000000000 +0200
+++ redmine-1.3.0_attachments/app/helpers/application_helper.rb	2011-12-24 23:52:55.014742768 +0200
@@ -537,8 +537,10 @@
     # when using an image link, try to use an attachment, if possible
     if options[:attachments] || (obj && obj.respond_to?(:attachments))
       attachments = options[:attachments] || obj.attachments
-      text.gsub!(/src="([^\/"]+\.(bmp|gif|jpg|jpe|jpeg|png))"(\s+alt="([^"]*)")?/i) do |m|
-        filename, ext, alt, alttext = $1.downcase, $2, $3, $4
+      text.gsub!(/((<img[^>]+src\s*=\s*)|(<a[^>]+href\s*=\s*))(("[^"]+")|('[^']+'))(\s+alt="([^"]*)")?/i) do |m|
+	prefix = $1
+	filename = $4.downcase.gsub(/^["'](.+)["']$/, '\1')
+	alt, alttext = $5, $6
         # search for the picture in attachments
         if found = Attachment.latest_attach(attachments, filename)
           image_url = url_for :only_path => only_path, :controller => 'attachments',
@@ -547,7 +549,11 @@
           if !desc.blank? && alttext.blank?
             alt = " title=\"#{desc}\" alt=\"#{desc}\""
           end
-          "src=\"#{image_url}\"#{alt}".html_safe
+	  if prefix =~ /^<img/i
+	    (prefix + "\"#{image_url}\"#{alt}").html_safe
+	  else
+	    (prefix + "\"#{image_url}\"").html_safe
+	  end
         else
           m.html_safe
         end