[ http://issues.apache.org/jira/browse/MODPYTHON-68?page=comments#action_12318143 ]
Graham Dumpleton commented on MODPYTHON-68: ------------------------------------------- I add my own -1 to this patch to add req.script_name. It is just as easy to stick it in a root level handler middleware wrapper. I would still like req.path_info to be writable though as it becomes impossible to write middleware wrappers that incorporate existing mod_python.publisher and mod_python.psp code otherwise. :-) The information here is still pertinent in pointing out that existing ways in which SCRIPT_NAME is determined is wrong in some situations. > Add a readable/writable req.script_name member. > ----------------------------------------------- > > Key: MODPYTHON-68 > URL: http://issues.apache.org/jira/browse/MODPYTHON-68 > Project: mod_python > Type: New Feature > Components: core > Versions: 3.2.0 > Reporter: Graham Dumpleton > Attachments: apache.py.diff > > The term SCRIPT_NAME in web servers is used to identify that part of a > URI which identifies the script handling the request. Within the URI, > the SCRIPT_NAME component would be followed by the PATH_INFO component, > the latter being potentially an empty string. > In mod_python, the value of SCRIPT_NAME could be obtained in a few > different ways. These are: > 1. Obtain it as req.subprocess_env["SCRIPT_NAME"] after having first > called req.add_common_vars(). > 2. Obtain it as apache.build_cgi_env(req)["SCRIPT_NAME"]. This > internally calls req.add_common_vars() but then ignores "SCRIPT_NAME" > value from req.subprocess_env and instead tries to calculate it as per > (3) below yeilding a different result to (1) in some cases. > 3. Attempt to derive it req.uri using code which is based upon something > like 'req.uri[:-len(req.path_info)]'. If req.path_info is empty, then the > result > should be the same as req.uri. > All three methods actually yield incorrect results in certain > circumstances, with the fact that it occurs in (1) suggesting an > underlying Apache bug. > The problem area is where there are multiple successive occurrences of > '/' appearing in the part of the URI which is used to determine the > PATH_INFO value. > Looking at some examples for each case we get: > req.uri = /~grahamd/handler/mptest.py > req.path_info = > PATH_INFO = None > SCRIPT_NAME (1) = /~grahamd/handler/mptest.py > SCRIPT_NAME (2) = /~grahamd/handler/mptest.py > SCRIPT_NAME (3) = /~grahamd/handler/mptest.py > req.uri = /~grahamd/handler/mptest.py/ > req.path_info = / > PATH_INFO = / > SCRIPT_NAME (1) = /~grahamd/handler/mptest.py > SCRIPT_NAME (2) = /~grahamd/handler/mptest.py > SCRIPT_NAME (3) = /~grahamd/handler/mptest.py > req.uri = /~grahamd/handler/mptest.py// > req.path_info = / > PATH_INFO = / > SCRIPT_NAME (1) = /~grahamd/handler/mptest.py > SCRIPT_NAME (2) = /~grahamd/handler/mptest.py/ > SCRIPT_NAME (3) = /~grahamd/handler/mptest.py/ > req.uri = /~grahamd/handler/mptest.py/a > req.path_info = /a > PATH_INFO = /a > SCRIPT_NAME (1) = /~grahamd/handler/mptest.py > SCRIPT_NAME (2) = /~grahamd/handler/mptest.py > SCRIPT_NAME (3) = /~grahamd/handler/mptest.py > req.uri = /~grahamd/handler/mptest.py/a/b > req.path_info = /a/b > PATH_INFO = /a/b > SCRIPT_NAME (1) = /~grahamd/handler/mptest.py > SCRIPT_NAME (2) = /~grahamd/handler/mptest.py > SCRIPT_NAME (3) = /~grahamd/handler/mptest.py > req.uri = /~grahamd/handler/mptest.py/a//b > req.path_info = /a/b > PATH_INFO = /a/b > SCRIPT_NAME (1) = /~grahamd/handler/mptest.py/a > SCRIPT_NAME (2) = /~grahamd/handler/mptest.py/ > SCRIPT_NAME (3) = /~grahamd/handler/mptest.py/ > req.uri = /~grahamd/handler/mptest.py/a///b > req.path_info = /a/b > PATH_INFO = /a/b > SCRIPT_NAME (1) = /~grahamd/handler/mptest.py/a/ > SCRIPT_NAME (2) = /~grahamd/handler/mptest.py/a > SCRIPT_NAME (3) = /~grahamd/handler/mptest.py/a > req.uri = /~grahamd/handler/mptest.py/a///b//c > req.path_info = /a/b/c > PATH_INFO = /a/b/c > SCRIPT_NAME (1) = /~grahamd/handler/mptest.py/a///b > SCRIPT_NAME (2) = /~grahamd/handler/mptest.py/a/ > SCRIPT_NAME (3) = /~grahamd/handler/mptest.py/a/ > All very strange and not what one would expect. > Ignoring the strange results, the first point of creating the tracker > item is to propose that a new member be added to the request object > referred to as "req.script_name". This new member should be both > readable and writable. > The argument for adding "script_name" is similar to that for making > "path_info" writable as described in MODPYTHON-67. That is, it would > make the task of writing a middleware stack specifically for mod_python > but in a similar style to WSGI a slightly simpler task. > In adding "script_name", it is perhaps suggested that its initial value be > somewhat saner than as shown in the results above. More along the lines > of: > req.uri = /~grahamd/handler/mptest.py// > req.path_info = / > script_name=/~grahamd/handler/mptest.py > req.uri = /~grahamd/handler/mptest.py/a//b > req.path_info = /a/b > script_name=/~grahamd/handler/mptest.py > req.uri = /~grahamd/handler/mptest.py/a///b > req.path_info = /a/b > script_name=/~grahamd/handler/mptest.py > req.uri = /~grahamd/handler/mptest.py/a//b//c > req.path_info = /a/b/c > script_name=/~grahamd/handler/mptest.py > It should perhaps also normalise the path to eliminate duplicate > instances of '/' in the URI appearing before the PATH_INFO component. > req.uri = /~grahamd/handler////mptest.py/a/b/c > req.path_info = /a/b/c > PATH_INFO = /a/b/c > SCRIPT_NAME (1) = /~grahamd/handler////mptest.py > SCRIPT_NAME (2) = /~grahamd/handler////mptest.py > SCRIPT_NAME (3) = /~grahamd/handler////mptest.py > script_name=/~grahamd/handler/mptest.py > In respect of the problems with (1) and (2), one probably should not do > anything about (1) as that is generated by Apache. As to (2), since it > is mean't to parallel what Apache provides, maybe it should just pass > through the "SCRIPT_NAME" from "req.subprocess_env". Not sure why the > latter ignores the value supplied by Apache and determines it itself, thus > yielding a different value in cases as shown. > And yes I do have an agenda by pushing these req.path_info and > req.script_name changes. My work should benefit mod_python though, > so don't be scared. ;-) -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira