access: InvenioWebAccessMailCookieError for non existing user email

[bouzlibop]

Steps to reproduce:

1. Go to sign in panel
2. Click Lost your password?
3. Provide some non existing email

Traceback (most recent call last):
 File "/opt/zenodo/src/invenio/invenio/ext/legacy/__init__.py", line 124, in __call__
   response = self.app.full_dispatch_request()
 File "/opt/zenodo/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
   rv = self.handle_user_exception(e)
 File "/opt/zenodo/lib/python2.7/site-packages/flask_restful/__init__.py", line 270, in error_router
   return original_handler(e)
 File "/opt/zenodo/src/invenio/invenio/base/wrappers.py", line 125, in handle_user_exception
   return super(Flask, self).handle_user_exception(e)
 File "/opt/zenodo/lib/python2.7/site-packages/flask/app.py", line 1<*****>81, in handle_user_exception
   reraise(exc_type, exc_value, tb)
 File "/opt/zenodo/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
   rv = self.dispatch_request()
 File "/opt/zenodo/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
   return self.view_functions[rule.endpoint](**req.view_args)
 File "/opt/zenodo/src/invenio/invenio/modules/accounts/views/accounts.py", line <*****>05, in lost
   if reset_password(request.values['email'], g.ln):
 File "/opt/zenodo/src/invenio/invenio/ext/login/__init__.py", line 56, in reset_password
   days=CFG_WEBSESSION_RESET_PASSWORD_EXPIRE_IN_DAYS))
 File "/opt/zenodo/src/invenio/invenio/modules/access/mailcookie.py", line 71, in mail_cookie_create_pw_reset
   "Email '%s' doesn't exist" % email)
InvenioWebAccessMailCookieError: Email '[email protected]' doesn't exist

The problem is in this line: https://github.com/inveniosoftware/invenio/blob/master/invenio/modules/access/mailcookie.py#L68

[bouzlibop]

Shall we notify user that provided email doesn't exist or shall we return some generic error page?

[jirikuncar]

I would go for generic error page for InvenioWebAccessMailCookieError exception ("Provided URL is not valid.").

[jirikuncar]

This problem is applicable on maint-2.0 too, hence I'm changing back the milestone.