Prevent traceback leaks.

lib/python/Products/PageTemplates/Expressions.py

@@ -89,7 +89,7 @@ Page Template-specific implementation of TALES, with handlers
 for Python expressions, string literals, and paths.
 """
 
-__version__='$Revision: 1.22 $'[11:-2]
+__version__='$Revision: 1.23 $'[11:-2]
 
 import re, sys
 from TALES import Engine, CompilerError, _valid_name, NAME_RE, \
@@ -180,16 +180,17 @@ class PathExpr:
         vars = econtext.vars
         exists = 0
         for base, path, dp in self._paths:
-            path = list(path) # Copy!
             # Expand dynamic path parts from right to left.
-            for i, varname in dp:
-                val = vars[varname]
-                if isinstance(val, StringType):
-                    path[i] = val
-                else:
-                    # If the value isn't a string, assume it's a sequence
-                    # of path names.
-                    path[i:i+1] = list(val)
+            if dp:
+                path = list(path) # Copy!
+                for i, varname in dp:
+                    val = vars[varname]
+                    if isinstance(val, StringType):
+                        path[i] = val
+                    else:
+                        # If the value isn't a string, assume it's a sequence
+                        # of path names.
+                        path[i:i+1] = list(val)
             try:
                 __traceback_info__ = base
                 if base == 'CONTEXTS':

lib/python/Products/PageTemplates/TALES.py

@@ -87,7 +87,7 @@
 An implementation of a generic TALES engine
 """
 
-__version__='$Revision: 1.22 $'[11:-2]
+__version__='$Revision: 1.23 $'[11:-2]
 
 import re, sys, ZTUtils
 from MultiMapping import MultiMapping
@@ -107,7 +107,11 @@ class TALESError(Exception):
         self.setPosition(position)
     def setPosition(self, position):
         self.lineno = position[0]
-        self.offset = position[1]        
+        self.offset = position[1]
+    def takeTraceback(self):
+        t = self.traceback
+        self.traceback = None
+        return t
     def __str__(self):
         if self.type is None:
             s = self.expression
@@ -314,8 +318,8 @@ class Context:
         try:
             v = expression(self)
             if isinstance(v, Exception):
-                if hasattr(v, 'traceback'):
-                    raise v, None, v.traceback
+                if isinstance(v, TALESError):
+                    raise v, None, v.takeTraceback()
                 raise v
         except TALESError, err:
             err.setPosition(self.position)

lib/python/Products/PageTemplates/ZopePageTemplate.py

@@ -87,7 +87,7 @@
 Zope object encapsulating a Page Template.
 """
 
-__version__='$Revision: 1.23 $'[11:-2]
+__version__='$Revision: 1.24 $'[11:-2]
 
 import os, AccessControl, Acquisition, sys
 from Globals import DTMLFile, ImageFile, MessageDialog, package_home
@@ -275,7 +275,8 @@ class ZopePageTemplate(Script, PageTemplate, Historical, Cacheable,
                 result = self.pt_render(extra_context=bound_names)
             except TALESError, err:
                 if err.type == 'Unauthorized':
-                    raise err.type, err.value, err.traceback
+                    raise err.type, err.value, err.takeTraceback()
+                err.takeTraceback()
                 raise
             if keyset is not None:
                 # Store the result in the cache.

lib/python/TAL/TALDefs.py

@@ -140,6 +140,11 @@ class TALESError(TALError):
 
     # This exception can carry around another exception + traceback
 
+    def takeTraceback(self):
+        t = self.info[2]
+        self.info = self.info[:2] + (None,)
+        return t
+
     def __init__(self, msg, position=(None, None), info=(None, None, None)):
         t, v, tb = info
         if t:

lib/python/TAL/TALInterpreter.py

@@ -637,8 +637,11 @@ class TALInterpreter:
             engine.beginScope()
             err.lineno, err.offset = self.position
             engine.setLocal('error', err)
-            self.interpret(handler)
-            engine.endScope()
+            try:
+                self.interpret(handler)
+            finally:
+                err.takeTraceback()
+                engine.endScope()
         else:
             self.restoreOutputState(state)
             self.stream_write(stream.getvalue())