psp.PSP doesn't work for a text string

• Key: MODPYTHON-48
• Type: Bug
• Status: Closed
• Resolution: Fixed
• Priority: Major
• Assignee: Unassigned
• Reporter: Graham Dumpleton
• Affects Version/s: 3.1.4
• Fix Version/s: 3.2.7

Description

The following code doesn't work.

  from mod_python import apache
  from mod_python import psp

  def handler(req):
       content_file = psp.PSP(req, string='hello world')
       content_file.run()
       return apache.OK

The problems range from typos in the Python code, the Python code
not actually compiling the parsed string and core dumps in PSP parser
due to double deletes.

Issues have been discussed on mailing list. Some of the main posts are:

  http://www.modpython.org/pipermail/mod_python/2005-April/017932.html
  http://www.modpython.org/pipermail/mod_python/2005-April/017938.html
  http://www.modpython.org/pipermail/mod_python/2005-April/017946.html

Patches are required to lib/python/mod_python/psp.py and src/_pspmodule.c.
These are include below. An independent check of whether removing explicit
destruction of the buffer in _pspmodule.c is the correct thing to do should be
done. Whether "__psp__" is an appropriate second argument to compile() in
change should be considered.

*** ../mod_python-3.1.3/lib/python/mod_python/psp.py Tue Feb 17 06:47:27 2004
--- lib/python/mod_python/psp.py Wed Apr 27 11:00:19 2005
***************
*** 111,122 ****
              self.load_from_file()
          else:
  
! cached = strcache.get(string)
              if cached:
                  self.code = cached
              else:
! self.code = _psp.parsestring(string)
! strcache.store(string)
  
      def cache_get(self, filename, mtime):
  
--- 111,124 ----
              self.load_from_file()
          else:
  
! cached = mem_scache.get(string)
              if cached:
                  self.code = cached
              else:
! source = _psp.parsestring(string)
! code = compile(source, "__psp__", "exec")
! mem_scache.store(string,code)
! self.code = code
  
      def cache_get(self, filename, mtime):
  
***************
*** 358,365 ****
  
      def get(self, key):
          if self.cache.has_key(key):
! hist, val = self.cache[key]
! self.cache[key] = (hits+1, code)
              return val
          else:
              return None
--- 360,367 ----
  
      def get(self, key):
          if self.cache.has_key(key):
! hits, val = self.cache[key]
! self.cache[key] = (hits+1, val)
              return val
          else:
              return None


*** ../mod_python-3.1.3/src/_pspmodule.c Tue Feb 17 06:47:27 2004
--- src/_pspmodule.c Wed Apr 27 10:43:51 2005
***************
*** 146,152 ****
      bs = yy_scan_string(PyString_AsString(str), scanner);
      yylex(scanner);
  
! yy_delete_buffer(bs, scanner);
      yylex_destroy(scanner);
      
      psp_string_0(&parser->pycode);
--- 146,152 ----
      bs = yy_scan_string(PyString_AsString(str), scanner);
      yylex(scanner);
  
! /* yy_delete_buffer(bs, scanner); */
      yylex_destroy(scanner);
      
      psp_string_0(&parser->pycode);