[FIX] mail: access link generaTION

Catch only the error related to the access of the linked record.
Previous was hidding error to access the ir.config_parameter and eventual other
errors from the orm.
Uses SUPERUSER_ID to access instance URL (e.g. portal has no access to it).
Fixes #4234 #4234

addons/mail/mail_mail.py

@@ -179,7 +179,10 @@ class mail_mail(osv.Model):
             related_user = partner.user_ids[0]
             try:
                 self.pool.get(mail.model).check_access_rule(cr, related_user.id, [mail.res_id], 'read', context=context)
-                base_url = self.pool.get('ir.config_parameter').get_param(cr, uid, 'web.base.url')
+            except except_orm, e:
+                pass
+            else:
+                base_url = self.pool.get('ir.config_parameter').get_param(cr, SUPERUSER_ID, 'web.base.url')
                 # the parameters to encode for the query and fragment part of url
                 query = {'db': cr.dbname}
                 fragment = {
@@ -190,8 +193,6 @@ class mail_mail(osv.Model):
                 url = urljoin(base_url, "?%s#%s" % (urlencode(query), urlencode(fragment)))
                 text = _("""<p>Access this document <a href="%s">directly in OpenERP</a></p>""") % url
                 body = tools.append_content_to_html(body, ("<div><p>%s</p></div>" % text), plaintext=False)
-            except except_orm, e:
-                pass
         return body
 
     def send_get_mail_reply_to(self, cr, uid, mail, partner=None, context=None):