Special URL handling for DTML pages
===================================
When a DTML page containing a head tag is visited, without a trailing
slash, the base href isn't set. When visited with a slash, it is:
>>> print http(r"""
... POST /+/zope.app.dtmlpage.DTMLPage%3D HTTP/1.1
... Authorization: Basic mgr:mgrpw
... Content-Length: 497
... Content-Type: multipart/form-data; boundary=---------------------------824954900632940947241835499
... Referer: http://localhost:8081/+/zope.app.dtmlpage.DTMLPage%3D
...
... -----------------------------824954900632940947241835499
... Content-Disposition: form-data; name="field.source"
...
...
...
...
... Eek
...
...
...
... -----------------------------824954900632940947241835499
... Content-Disposition: form-data; name="UPDATE_SUBMIT"
...
... Add
... -----------------------------824954900632940947241835499
... Content-Disposition: form-data; name="add_input_name"
...
... dtml.html
... -----------------------------824954900632940947241835499--
... """)
HTTP/1.1 303 See Other
...
>>> print http(r"""
... GET /dtml.html HTTP/1.1
... Authorization: Basic mgr:mgrpw
... """)
HTTP/1.1 200 Ok
...
Eek
>>> print http(r"""
... GET /dtml.html/ HTTP/1.1
... Authorization: Basic mgr:mgrpw
... """)
HTTP/1.1 200 Ok
...
Eek