manage_changeProperties() and manage_addProperty() behave differently for "lines"

[Berthold Stöger]

For "lines"-properties manage_addProperty() casts an array of ints to an array of strings, whereas manage_changeProperties() does not. This is against the principle of least surprises.

This PythonScript:
"""
 ## Script (Python) "testbug"
 ##bind container=container
 ##bind context=context
 ##bind namespace=
 ##bind script=script
 ##bind subpath=traverse_subpath
 ##parameters=
 ##title=
 ##
 def is_int(i):
   try:
     i + 1
     return "is int"
   except:
     return "isn't int"

 try: obj.manage_delProperties(ids=('testproperty',))
 except: pass

 obj = script
 print "Add property..."
 obj.manage_addProperty('testproperty', [1,2,3], 'lines')
 for i in obj.testproperty: print is_int(i)

 print "Change property..."
 obj.manage_changeProperties(testproperty=[1,2,3])
 for i in obj.testproperty: print is_int(i)

 return printed
"""
returns
"""
 Add property...
 isn't int
 isn't int
 isn't int
 Change property...
 is int
 is int
 is int
"""
which is not what one would expect.

[Andreas Jung (ajung)]

Status: Pending => Wontfix

Type converters only deal with the outer type but not with the types of contained elements. This should be handled on the application level.

[Tres Seaver (tseaver)]

Touch this issue to get its transcript mailed out after today's
mailhost failures.

[Florent Guillaume (efge)]

Status: Wontfix => Pending

This doesn't explain the difference of behaviour between the two methods.
Reopening.
See http://mail.zope.org/pipermail/zope/2006-June/166882.html

[Jens Vagelpohl (dataflake-deactivatedaccount-deactivatedaccount)]

The type converter in question (ZPublisher.Converters.field2lines) does indeed touch the contained elements and converts them to strings. However, the behavior has existed for over 11 years now. I'm questioning the wisdom of changing it now and potentially breaking existing applications.

[Colin Watson (cjwatson)]

The zope2 project on Launchpad has been archived at the request of the Zope developers (see https://answers.launchpad.net/launchpad/+question/683589 and https://answers.launchpad.net/launchpad/+question/685285). If this bug is still relevant, please refile it at https://github.com/zopefoundation/zope2.