req.add_handler/req.handler and PythonInterpPerDirective

• Key: MODPYTHON-160
• Type: Bug
• Status: Closed
• Resolution: Fixed
• Priority: Major
• Assignee: Graham Dumpleton
• Reporter: Graham Dumpleton
• Component/s: core
• Affects Version/s: 3.2.8
• Fix Version/s: 3.3.1

Description

MODPYTHON-125 made req.handler writable. Being able to now do this has uncovered a bug whereby if PythonInterpPerDirective is used mod_python can cause Apache to crash. Code to trigger the problem is:

# .htaccess

SetHandler mod_python
PythonInterpPerDirective On
PythonFixupHandler interpreter_1

# interpreter_1.py

from mod_python import apache

def fixuphandler(req):
    req.log_error("fixuphandler")
    req.log_error("interpreter=%s"%req.interpreter)
    req.log_error("directory=%s"%req.hlist.directory)
    req.handler = "mod_python"
    req.add_handler("PythonHandler","interpreter_1")
    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

In summary, if PythonHandler is not used in Apache configuration to enable mod_python but it is done by assignment to req.handler in fixup phase and then req.add_handler() is used to add a handler to be called for content phase, and PythonInterpPerDirective is being used, mod_python will cause Apache to crash.

Location of crash not yet identified.