resource_exists in trac.ticket.api should avoid database exceptions from invalid input

[Ryan J Ollos]

Reported in ​th:#12253, the function resource_exists in trac.ticket.api raises an exception on PostgreSQL when resource.id is not an integer.

Perhaps we should simply try converting resource.id to an integer in resource_exists​:

try:
   id_ = int(resource.id)
except ValueError:
   return False

[Jun Omae]

I think we should catch both TypeError and ValueError.

>>> from trac.resource import Resource
>>> resource = Resource('ticket')
>>> resource
<Resource 'ticket'>
>>> resource.id is None
True
>>> int(resource.id)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: int() argument must be a string or a number, not 'NoneType'

[Ryan J Ollos]

Replying to jomae:

I think we should catch both TypeError and ValueError.

Thanks. Proposed changes in log:rjollos.git:t12076-resource-exists-trap-exception.

[Ryan J Ollos]

Committed to 1.0-stable in [14090], merged to trunk in [14091].