I need a class "machine" that can be linked to by other
classes. Since there are *many* machines, I want a
field, not a menu for machines. This doesn't work if
there are machines with names like "12345" consisting
of digits only. If I'm selecting such a machine using
classhelp, I get an error message "machine has no node
12345".

To reproduce with the standard "classic" tracker:
- create a new tracker with postgresql backend
- Add a new priority named "12345"
- edit issue.item.html to make the priority a field
with classhelp:
 <td>
  <span tal:replace="structure context/priority/field"/>
  <span tal:replace="structure python:db.priority.classhelp
       ( 'name,order'
       , property='priority'
       , inputtype='radio'
       , width='600'
       )"/>
 </td>
- Add a new issue and select the priority "12345" by
either using classhelp or manual input
-> error message "Error: priority has no node 12345"

If I'm entering a non-existant priority, I'm getting a
traceback: ERROR:  invalid input syntax for integer: "1
2345a"(see attached file). Here I expect an error
message, e.g., "Error: priority has no node 12345a".

Seems like cgi/actions.py directly hands the
untranslated value '12345' to the backend (if I'm
throwing a different exception in line 1347 of
backends/rdbms_common.py, I'm getting a traceback
indicating that the offending value was passed to the
backend). I think it should do a lookup first --
similar to the new modified lookupIds method in
cgi/templating.py, see also the related bug-report
https://sourceforge.net/tracker/?func=detail&atid=402788&aid=1424550&group_id=31577
"IndexError when copying an issue".

Note that I'm also seeing the untranslated '12345' for
the priority in an auditor!

I currently have no idea where this should be fixed, if
an existing name of a priority is input I'm seeing the
id of the priority in the backend (and the auditor),
not the name, so it looks similar to the bug in the
bug-report mentioned above.

I don't have a solution for this but I think this is another victim of "ids are strings and not ints". We force Link and Multilink values to be strings and then we need to determine whether that string is an id or a key during the creation. Currently we assume it is an id if it matches a number regexp and a key otherwise. This breaks down when the keys are also integers.