Wrong interpreter chosen with req.add_handler()/PythonInterpPerDirective.
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Key: MODPYTHON-161
URL: http://issues.apache.org/jira/browse/MODPYTHON-161
Project: mod_python
Type: Bug

Components: core
Versions: 3.3
Reporter: Graham Dumpleton


Having fixed MODPYTHON-160, if using:

# .htaccess

SetHandler mod_python
PythonInterpPerDirective On
PythonFixupHandler interpreter_1

# interpreter_1.py

from mod_python import apache
import os, sys

directory = os.path.dirname(__file__)

def fixuphandler(req):
req.log_error("fixuphandler")
req.log_error("interpreter=%s"%req.interpreter)
req.log_error("directory=%s"%req.hlist.directory)
req.add_handler("PythonHandler","interpreter_1",directory)
return apache.OK

def handler(req):
req.log_error("handler")
req.log_error("interpreter=%s"%req.interpreter)
req.log_error("directory=%s"%req.hlist.directory)
req.content_type = 'text/plain'
req.write('hello')
return apache.OK

when select_interp_name() in src/mod_python.c tries to determine the interpr
eter name, for PythonInterPerDirective, it will use the value as supplied as
 directory argument to req.add_handler(). In doing this though, it doesn't c
onsider the fact that the d
irectory may not have a trailing slash and since interpreter names for Pytho
nInterpPerDirective always have a trailing slash, the handler will not be ex
ecuted in correct interpreter context.

[Sun Apr 16 17:20:00 2006] [notice] mod_python: (Re)importing module
 'interpreter_1'
[Sun Apr 16 17:20:00 2006] [error] [client ::1] fixuphandler
[Sun Apr 16 17:20:00 2006] [error] [client ::1] interpreter=/Use
rs/grahamd/Workspaces/testing/interpreter-1/
[Sun Apr 16 17:20:00 2006] [error] [client ::1] directory=/Users
/grahamd/Workspaces/testing/interpreter-1/
[Sun Apr 16 17:20:00 2006] [notice] mod_python: (Re)importing module
 'interpreter_1'
[Sun Apr 16 17:20:00 2006] [error] [client ::1] handler
[Sun Apr 16 17:20:00 2006] [error] [client ::1] interpreter=/Use
rs/grahamd/Workspaces/testing/interpreter-1
[Sun Apr 16 17:20:00 2006] [error] [client ::1] directory=/Users
/grahamd/Workspaces/testing/interpreter-1

A further problem is that normally the path indicating where a directive was
 defined is internally calculated from Apache configuration and thus always 
uses POSIX directory conventions, ie., forward slash. If the above code were
 run on Win32, the director
y calculated from __file__ is going to most likely use DOS directory convent
ions, ie., backward slash. Thus, even if a trailing slash were to be added, 
it still will not work because the remainder of the path is going to use bac
kward slash and thus the in
terpreter name still will not match what it probably should be.

The main purpose of the directory argument to req.add_handler() is to know w
here to find the module referenced in the handler argument. In this case it 
is also used to determine the Python interpreter name. The fix may be that t
he interpreter name be dete
rmined in some other way based on the interpreter in use when the req.add_ha
ndler() call was made.

This is just part of problems I can possibly see with calculation of interpr
eter names for handlers. More on this another time. :-)

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