CHANGES.txt

Zope Changes

This file contains change information for the current Zope release. Change information for previous versions of Zope can be found in the file HISTORY.txt.

Zope 2.7.0 rc 2

Bugs Fixed

One of the 2.6.3 fixes added a previously missing security check when binding context and container to Python Scripts. Because many existing scripts appear in containers that users cannot access, this caused a lot of unauthorized errors in existing (mostly CMF) sites, since container is bound by default. The fix has been adjusted so that an unauthorized is only raised if the bound name is actually used in a script, making backward compatibility much better.
Collector #1154 / # 615: interaction with sessions could cause the security context to be discarded, potentially breaking scripts that depend on proxy roles.
Stopped overriding the version of xmlrpclib in the Python standard library. As of Python 2.3, the standard xmlrpclib now includes all the features Zope needs, plus bugfixes and integration with new Python types.
A pre-existing bug that could cause subtly different results when calling the C vs. Python version of validate() through the authorize() method of a UserFolder was found and fixed.
An inadvertant change to the behavior of Owned.getOwner was reverted.
Fix for bug 1207: errors building in read-only directories.

Zope 2.7.0 rc1

Bugs Fixed

Collector #1182: Functions for handling decisions about unprotected subobjects were not passed "names" when doing unnamed (item) access. In 2.6.3 we changed access checks when doing item access to pass None rather than the key value when validating access. This broke some existing applications. We have reverted these changes.
Collector #1186: some globals required to support certain operations in restricted code (e.g., list comprehensions in DTML expressions) were not propagated to all the right places.
Collector #1074: Change Scripts' __name__ to None, added unit tests for the effect of __name__ on class definitions and imports.
README.txt (and other file-like objects or directories without an __init__.py) on the Products path are no longer considered to be Products. A warning message is no longer raised about duplicate README.txt "products" upon startup in a default installation.
XMLRPC queries failed due to a missing import.
Forward-ported Toby's unicode encoding hacks for propertysheets from the 2.6 branch.
Some potential refcount issues in cAccessControl.c were fixed.
Fixed bug in ZEO server's monitor option. The -m / --monitor option used to specify the monitor address did not work.

Zope 2.7.0b4

Default config file changes

Zope no longer creates "default" ZODB databases if none exist in the zope config file. At least one database (the root database, at mount-point /) must be specified in zope.conf for Zope to start properly now. In zope.conf files generated by older 2.7 betas, just uncomment the "main" and "temporary" zodb_db definitions in the zope.conf file to be in parity with what would have been generated in 2.7b4 and beyond.
Zope no longer configures a "default" set of servers if no servers are specified in the config file. If no servers are specified in the config file, no servers are started.

Features added

Folder listings in FTP now include "." as well as "..".
Using "_usage" parameters in a ZCatalog query is deprecated and logged as DeprecationWarning.
Added a "mime-types" configuration value which names a file giving additional MIME type to filename extension mappings. The "mime-types" setting may be given more than once in the configuration file; the files have the same format at the mime.types file distributed with Apache.
Added a "warnfilter" config directive which allows for the specification of Python warning filters from within the Zope configuration file.
When a VHM is activated, it adds the mapping 'VIRTUAL_URL_PARTS': (SERVER_URL, BASEPATH1, virtual_url_path) to the request's other dictionary. If BASEPATH1 is empty, it is omitted from the tuple. The joined parts are also added under the key VIRTUAL_URL. Since the parts are evaluated before traversal continues, they will not reflect modifications to the path during traversal or by the addition of a default method such as index_html.
Added VHM regression tests to the SiteAccess product. Also see Collector #809.
Updated the interactive Zope tutorial to use ZPT in place of DTML.
When installing, symlink the Python used to build Zope into the installed bin directory (unless it has a python already).
Python 2.3 builtins sum, dict, and enumerate exposed to guarded code.

Bugs fixed

Collector #1140: setting the access control implementation from the configuration file didn't work. The ZOPE_SECURITY_POLICY environment variable is no longer honored.
Browsers that do not escape html in query strings such as Internet Explorer 5.5 could potentially send a script tag in a query string to the ZSearch interface for cross-site scripting.
FilteredSets (used within TopicIndex) are defined via an expression, which was naievely eval'ed.
The ZTUtils SimpleTree decompressed tree state data from the request without checking for final size, which could allow for certain types of DoS attacks.
Inadequate security assertions on administrative "find" methods could potentially be abused.
Some improper security assertions on DTMLDocument objects could potentially allow access to members that should be protected.
Class security was not properly intialized for PythonScripts, potentially allowing access to variables that should be protected. It turned out that most of the security assertions were in fact activated as a side effect of other code, but this fix is still appropriate to ensure that all security declarations are properly applied.
The dtml-tree tag used an "eval" of user-supplied data; its efforts to prevent abuse were ineffective.
XML-RPC marshalling of class instances used the instance __dict__ to marshal the object, and could include attributes prefixed with an underscore name. These attributes are considered private in Zope and should generally not be disclosed.
Some property types were stored in a mutable data type (list) which could potentially allow untrusted code to effect changes on those properties without going through appropriate security checks in particular scenarios.
Inadequate type checking could allow unicode values passed to RESPONSE.write() to be passed into deeper layers of asyncore, where an exception would eventually be generated at a level that would cause the Zserver main loop to terminate.
The variables bound to page templates and Python scripts such as "context" and "container" were not checked adequately, allowing a script to potentially access those objects without ensuring the necessary permissions on the part of the executing user.
Iteration over sequences could in some cases fail to check access to an object obtained from the sequence. Subsequent checks (such as for attributes access) of such an object would still be performed, but it should not have been possible to obtain the object in the first place.
List and dictionary instance methods such as the get method of dictionary objects were not security aware and could return an object without checking access to that object. Subsequent checks (such as for attributes access) of such an object would still be performed, but it should not have been possible to obtain the object in the first place.
Use of 'import as. in Python scripts could potentially rebind names in ways that could be used to avoid appropriate security checks.
A number of newer built-ins (min, max, enumerate, iter, sum) were either unavailable in untrusted code or did not perform adequate security checking.
Unpacking via function calls, variable assignment, exception variables and other contexts did not perform adequate security checks, potentially allowing access to objects that should have been protected.
DTMLMethods with proxy rights could incorrectly transfer those rights via acquisition when traversing to a parent object.
Range searches with KeywordIndexes did not work with record-style query parameters
Collector #484: Depending on the server's timezone (east of Greenwich) and os (Windows) _calcTimezoneName didn't work with 1970/01/01 and some other special dates.
Item_w__name__ now has a working getId() method
PageTemplateFile now using Item_w__name__ mixin, fixing its getId() and absolute_url() methods.
PCGI, FCGI, and HTTP servers now check for unicode types in their close methods.
Only one VirtualHostMonster is allowed per container.
Collector #1133: TreeTag choked on Ids of type long.
Collector #1012: A carefully crafted compressed tree state could violate size limit. Limit is no longer hardcoded.
Collector #1139: tal:attributes didn't escape double quotes.
Collector #809: Added and documented Traversable.py methods absolute_url_path and virtual_url_path, and reverted earlier change to absolute_url behaviour.
Collector #927: Raise a more specific exception than BadRequest when disconnected.
Collector #1129: Improper parsing of ISO8601 in DateTime.
updated docutils packages (fixes several problems with RestructuredText)
Fixed a bug in the ZEO server's getInvalidations() method. If it had the requested invalidations, it would send all the invalidations in its queue rather than just the requested ones. This didn't affect correctness of the cache, but did cause it to throw out valid data.

Zope 2.7.0b3

Features added

Add parity method to ZTUtils Iterators.
Allow untrusted code to mutate ZPublisher record objects.
Changed the ZEO server and control process to work with a single configuration file; this is now the default way to configure these processes. (It's still possible to use separate configuration files.) The ZEO configuration file can now include a "runner" section used by the control process and ignored by the ZEO server process itself. If present, the control process can use the same configuration file.
ZConfig was updated to version 2.0. The new version includes two new ways to perform schema extension; of particular interest in Zope is the ability for a configuration file to "import" new schema components to allow 3rd-party components (such as storages, databases, or logging handlers) to be used.
Add an update_metadata keyword argument to instances of a Catalog's catalogObject method and an ZCatalog's catalog_object method. This argument defaults to true. If this argument is specified false, the catalog update will not update the metadata for the object. If the obejct has never been cataloged before, the metadata is always added and the flag has no effect.
The standard ProperyManager now includes the same label functionality as the CMF SimpleItemWithProperties object. By adding a label entry to the property definition you can now display a prettier label for the property.

Bugs fixed

Removed all cases where string literals were raised as exceptions, and where named strings caused deprecation messages during unit tests (some named strings may still be hiding in the woodwork).
AccessControl.User used a misleading string exeception, NotImplemented, which shadowed the Python builtin.
Collector #1112: logfile reopening didn't work.
Collector #1110: Under Python 2.3, some DateIndex tests were failing.
Collector #426: Inconsistent, undocumented error() method.
Collector #799: Eliminate improper uses of SCRIPT_NAME.
Collector #445: Add internal global declaration for Script bindings.
Collector #616: Make CONTEXTS available to TALES Python expressions.
Collector #1074: Give Script execution context a __name__
Collector #1095: Allow TAL paths starting with /varname as a preferred spelling for CONTEXTS/varname.
Collector #391: Cut and paste now requires delete permissions.
Collector #331: Referenses to URL in manage_tabs was changed to REQUEST.URL to prevent accidental overriding.
Made the control panel properly reflect the cache-size setting of ZODB's object cache once again.
ConflictError was swallowed in ObjectManager by manage_beforeDelete and _delObject. This could break code expecting to do cleanups before deletion.
Python 2.3 BooleanType wasn't handled properly by ZTUtils marshalling and ZPublisher's converters.
Collector #1065: bin/ scripts didn't export HOME envars.
Collector #1034: METAL macros with content-type text/xml raised Unauthorized errors inappropriately.
Collector #572: WebDAV GET protected by FTP Access permission. Two new methods have been added to WebDAV resources, "manage_DAVget" and "listDAVObjects". These are now used by WebDAV instead of the earlier "manage_FTPget" and "objectValues". This separates the permissions, and allows WebDAV specific overriding of these methods.
Workaround for Collector #1081: The title property for objects derived from OFS.Folder or PropertyManager can now be removed and replaced with a ustring property. This allows the usage of non-ISO-8859-1 or ASCII charsets
profile-publisher-file config file directive now works properly (thanks to Andy McKay for the report).
Collector #904: Platform specific signals in zdaemon/Daemon.py (fixed by removing the "fossil" module from 2.7 branch and head).
Collector #951: DateTime(None) now equal to DateTime()
Collector #1056: aq_acquire() ignored the default argument
Collector #1087: ZPT: "repeat/item/length" did not work as documented in the Zope Book.
Collector #1079: Fixed BaseRequest's traversal loop to avoid some infinite loop scenarios.
The View tab in the ZMI in some cases pointed back to manage_workspace.
Added the name "context" as a synonym for "here" in page templates, since "context" is better understood. This unifies the convention in templates, scripts, and Zope 3.
Disassociate zeo-client-name from enable-product-installation ZConfig keys. In the past, if you ran an appserver as ZEO client with a persistent cache, the startup logic prevented products from being loaded. This was a hack that got baked in via the weird interaction between the FORCE_PRODUCT_LOAD and ZEO_CLIENT environment variables and was carried over into Zope 2.7 by inertia. Now they have nothing to do with each other and can be specified independently.
Monitor server would start even if an emergency user didn't exist.
Collector #721: Entities in tal:attribute values weren't properly escaped.
Collector #851: Traversable.py: A bare try..except shadowed conflict errors
Collector #1058: Several fixes for PropertySheets when used outside ZClasses
Collector #1053: parseIndexRequest turned empty sequence of search terms into unrestricted search.
manage_tabs had a namespace problem with the acquisition of names from the manage_options variable resulting to acquire "target" and "action" from objects above in the hierachy.
PathIndex and TopicIndex are now using a counter for the number of indexed objects instead of using a very expensive calculation based on the keys of their indexes.
Collector #1039: Whitespace problem in Z2.log fixed
Collector #78: Proxy roles not respected when calling manage_pasteObjects.
changed some bare try: except:'s in Shared.DC.ZRDB.Connection so that they now log exceptions that occur.
Responses from Zope's FTP server could sometimes be HTML!

7.0b2
Features added
- New zopectl feature: adduser. Instead of using the inituser mechanism, "zopectl adduser " will add a user with the Manager role to your site. This is useful both interactively and for packagers.
- New top-level package: nt_svcutils. This takes the place of the Zope.Startup.nt package to allow for reuse outside of Zope.
- Renamed the "service file" for a Zope instance under Windows from ntservice.py to zopeservice.py to allow a ZEO server instance to share the same instance home as a Zope instance (the ZEO service file will be called zeoservice.py).
- The TemporaryStorage module was moved from Products/TemporaryFolder to a new top-level package named tempstorage.
- Split functionality of mkzopeinstance into two separate modules: mkzopeinstance.py and copyzopeskel.py. copyzopeskel.py can be used directly by packagers to install custom skeleton directories or mkzopeinstance can use a custom skeleton directory via the --skelsrc flag.
- Added environment and path directives to config file directive list. environment is a section which allows the user to specify environment variables within the config file. path allows the user to specify additional directories to insert into sys.path when configuration is processed.
- Moved temporary storage related files into their own module within lib/python, out of Products.TemporaryStorage. This was necessary in order to prevent the configuration machinery from prematurely importing some modules that it didn't need to during startup (the transitive set of all imported modules within Products.TemporaryStorage).
- Add a check to the configurator to ensure that the Python found has an expat parser.
Bugs fixed
- The Products directory in an instance home was not automatically added to the Products.__path__ (it needed to be specified manually). It is now automatically added at instance startup.
- The Windows runzope.bat file generated by mkzopeinstance from the default skeleton directory now uses python.exe instead of pythonw.exe, so you can actually see output from the Zope process when you run it interactively.
- backport of TAL fixes from z3
  - i18n and metal interactions
  - fix handling of nested translations with tal:content/replace and i18n:name
- Collector #1017: reST has been broken
- backward compatibility for i18n:attributes
  if items are separated with spaces and there are more than two items, all are treated as attributes plus deprecation warning
  
  if items are separated with spaces and there are two items :
  - i18n:attributes="value msg_id;" (with semicolon) will always be treated as
  - i18n:attributes="value title" will be treated as as long as title exist as attribute (both as static or in tal:attributes) plus deprecation warning
- deny attributes being both part of tal:attributes and having a messageid in i18n:attributes
- Fixed failing Zope.Startup tests caused by import of nonexistent Startup.getSchema function.
- VHM: manage_edit has been broken
- The container-class keyword to database sections didn't work.
- ZConfig didn't report a line number and munged capitalization of replacement keys when a replacement error was provided.
- log-to-stderr on startup will now emit messages to the console at the lowest logging level defined by any of the handlers in the eventlog section.
- entirely removed warning when the starting user's umask is "too permissive". it wasn't clear that it added any value under normal operations.
- debug-mode config file option did not work.
- ZClasses that subclassed ObjectManager that were created in earlier versions of Zope would not load under 2.6, due to the new Interfaces package. Added back a simple stub module and changed a constructor to allow these ZClasses to work.
- Bugfix: if zopectl is run as the root user, the debug, run, and adduser commands will cause the Python process which performs those actions to switch users to the effective user. This prevents ZODB index files, log files, etc. from being written as root, potentially preventing later startup by the effective user.
- Bugfix: allow the zopectl process to ascertain the program that zdrun should run from the Zope config file. This is necessary if the file is moved out of a "single-directory-as-instance" instance home.
- Various fixes to content of ZopeTutorial to deal with URLs moving on new.zope.org (thanks to Stefane Fermigier).
- Added optparse and textwrap modules to docutils package to prevent ReST barfage (AJ).
- Added a sample zeoclient and tempstorage stanzas to the default config file (zope.conf.in).
- Various tweaks to the dbtab configuration code (Shane).
- Various fixes/enhancements to ZODB/ZEO (PythonLabs).
- Removed inst/Zope.spec Zope RPM spec file in favor of placing it in a separate internal ZC repository. It will be available in the SRPM.
- Fix for Collector 823 (XML RPC exception values were always converted to strings and thus turned into a Fault object). Thanks to Sandor Palfy for the patch.
- Remove --zeo/-z flags from mkzopeinstance.py, as custom_zodb.py is no longer the preferred method of configuring custom storages now that we have DBTab in the core, and you should be able to create a custom skeleton dir with the right zope.conf.in that has a zeo client storage set up if you need to.
- make sdist now creates a file with an extension of .tgz rather than ..tar.gz (mainly to meet the expectations of Zope.org about file names).
- moved zpasswd.py into utilities directory in source tree.

Zope 2.7.0b1

Features added

zopectl command now has debug and run options.
the zodb_db section in zope.conf now accepts a connection-class key that accepts a python dotted-path-name to use as the connection class for the database.
The ReST input and output encodings are now configured via the rest-input-encoding and rest-output-encoding config file directives rather than the REST_INPUT_ENCODING and REST_OUTPUT_ENCODING environment variables.
Datetime-format settings are now configured via the datetime-format configuration file directive rather than the DATETIME_FORMAT environment variable.
Trusted proxies are now configured via the trusted-proxy configuration file directive rather than the ZOPE_TRUSTED_PROXIES environment variable.
The maximum number of sockets that ZServer will open in order to service incoming connections can now be specified via the max-listen-sockets conf file parameter.
Shane Hathaway's DBTab product has been integrated. The Control_Panel -> Databases tab now allows you to control all mounted databases. You can add a mount point by editing the zope.conf file, adding a zodb_db section for the main database and other mounted databases, and choosing "ZODB Mount Point" from the Zope "Add" list.
DTML Methods and Documents supply a traceback supplement when called.
Windows installer contains NT/2K/XP service support on a per-instance-home basis.
zopectl command now has debug and run options.
the zodb_db section in zope.conf now accepts a connection-class key that accepts a python dotted-path-name to use as the connection class for the database.

Bugs Fixed

mkzopeinstance did not expand tildes in directory name input.
The configure script did not work under Solaris sh.
The SiteErrorLog object did not ignore NotFound errors, which caused (mainly) useless messages to be kept in the log.
The addition of a linefeed to version.txt in lib/python caused Apache proxies to choke because the string was injected into a header including the linefeed. This has been fixed.
Collector: #964: standard_error_message refers to looking into the HTML code for more information which is deprecated. Referring to the error log now.
Collector #893: Mailhost: munge_header has been broken for addresses containing the recipients full name
Zope's setup.py didn't include the ZEO.auth package.
Collector #628: Applied patch to fix several textarea resize problems.
Collector #953: fixed namespace collision with form_title in ZMI
Collector #342: Avoiding insertion of a BASE tag for file objects with content-type text/html
Windows installer properly deletes pyc/pyo files on uninstall.
Windows binary post-install quickstart page is now more informative.
Fixed a potential bug in ZTUtils.Tree.decodeExpansion where a potentially empty string was tested for it's first character; used .startswith for safety.

Zope 2.7.0a1

Features added

OFS: OrderSupport and OrderedFolder added. OrderSupport is a mixin class that adds the IOrderedContainer interface to ObjectManagers. OrderedFolder - meta_type Folder (Ordered) - is a new Folder class using OrderSupport. (thanks to Stephan Richter for inspiration and some code)
Folder: Constructor now takes an optional id argument.
Show known medusa servers in Control_Panel.
New startup and installation regime (./configure; make; make install instances use a config file, daemon is now a separate process). See http://dev.zope.org/Wikis/DevSite/Proposals/InstallationAndConfiguration for more information.
New module: App.config. New API for getting a configuration object. This should be the preferred way for all code in Zope to get configured values for many settings. For settings made available via this module, alternate locations are deprecated, though will to be supported for Zope 2.7.
Collector #435: Support for passwords encoded using MySQL's PASSWORD() function add to lib/python/AccessControl/AuthEncoding.py.
Collector #167: Support __getattr__ on cAccessControl PermissionRole objects to allow gathering of permission names for products like DocFinder and VerboseSecurity.
Added a new REQUEST method, getClientAddr(), to determine a clients IP address. Address restrictions in the user folder have been changed to use this method. By default the value returned by this method is the same as the initial value of REQUEST['REMOTE_ADDR']. Zope also has support for obtaining a more useful value from other headers if a front-end proxy is in use. See doc/ENVIRONMENT.txt for details.
DateTime module: added support to parse international dateformats. The Datetime constructor has a new "datefmt" parameter to enforce the parsing of a date as "us" or "international" date. The new field descriptor field descriptor "date_international" can be used to enforce this behaviour inside the ZPublisher. See also doc/ENVIRONMENT.txt to check with the DATETIME_FORMAT
KeywordIndex, FieldIndex and ZCTextIndex are now able to index more than one attribute of an object. This removes the ties between the indexes ID and the attribute name to be indexed.
Integration of reStructuredText (reST) and the ZReST product by Richard Jones. See doc/RESTRUCTUREDTEXT.txt for details.
Objects locked through WebDAV are now marked with a lock icon inside the ZMI.
Collector #741: Applied patch to provide better FTP error messages.
Made all PluginIndexes and ZCTextIndex use safe_callable, which is aware of extension classes that fill tp_callable but don't define __call__.
Made KeywordIndex be more robust about receiving a value that is not a string or an iterable type.

Bugs Fixed

Collector #954: clear() method of TopicIndex removed all filter sets instead of clearing them.
Collector #939: Fixed typo in TopicIndexes
Collector #937: UnicodeError exception available within PythonScripts
Collector #902: recursive Scripts were broken due to shared globals.
Product initialization would only consult a file named "version.txt" to read version information. Now it will check version.txt, VERSION.txt and VERSION.TXT.
Collector #928: DateIndex ignored timezones when indexing and querying
Collector #892: misleading error msg when initializing an OIBTree from a dict with a float value. The message claimed that the dict's items didn't consist of 2-element tuples, but of course they do. The TypeError now says "expected integer value".
Collector #882: delPropertySheet was broken due to a typo
Collector #683: WeDAV request without XML preamble were not recognized by Zope and raised an exception.
Index constructors were called without acquisition context of the calling object. This caused caller.getPhysicalPath() to fail for indexes depending on this information.
Collector #814: PathIndexes now uses IITreeSet instead of IISet. This should result in less memory usage.
Fixed a whitespace problem in Z2.log (AWStats failed to process Zope logfiles)
Collector #816: dtml-sendmail corrupted header if message was left blank.
Collector #790: WebDAV access is granted by default only to Managers and Authenticated users instead to Anonymous users. This restricts access to the Control_Panel and especially to the Products management to trusted users.
Rename, Cut & Delete operations on locked objects (WebDAV) are no longer permitted and will raise an exception. Copies of locked objects are copied without lock.
Collector #634: Image objects can now be rendered without border attribute by calling "image.tag(border='')".
Collector #695: Object IDs "." and ".." are no longer permitted.
Collector #771: ZCatalog failed to index DTML Document if the name of a catalog metadata was identical with the name of an acquired object.
Collector #686: intSets no longer lose their values.
Collector #685: Improved documentation explaining how, where and why security assertions should be placed in: lib/python/Products/PythonScripts/README.txt lib/python/Products/PythonScripts/module_access_examples.py
The ZEO unit tests and wo_pcgi.py didn't run on Windows if the path to the python executable included a space.
Some calls to os.system(chmod) has been replaced with the more portable os.chmod() call, to make install work properly on Windows.
Fixed an isinstance() check in SimpleItem on standard_error_message handling that would always break if the first argument was not an extension class because the second argument was a type.
Any write request could be tricked into writing into a version be setting a version cookie or by including a version name in the request. Now we require the user to globally have permission to join or leave versions to run a request in a version.

Backward incompatabilities

We no longer honor local security settings that would allow someone to join or leave versions unless the location of the settings is a folder directly or indirectly containing the user's user folder.

Bugs Fixed

Collector #956: automatically installing Examples at startup could be a security risk. Examples now must be installed explicitly by the user (thanks to Jamie Heilman and day0).
Collector #954: clear() method of TopicIndex removed all filter sets instead of clearing them.
Collector #882: Fixed typo in PropertySheets
Collector #939: Fixed typo in TopicIndexes
Collector #937: UnicodeError exception available within PythonScripts
Collector #902: recursive Scripts were broken due to shared globals.
Product initialization would only consult a file named "version.txt" to read version information. Now it will check version.txt, VERSION.txt and VERSION.TXT.
Make ZCTextIndex much less prone to generating conflict errors. Previously any concurrent updates would provoke a conflict.
Fix query performance and scalability bug in ZCTextIndex.
Collector #928: DateIndex ignored timezones when indexing and querying
Any write request could be tricked into writing into a version be setting a version cookie or by including a version name in the request. Now we require the user to globally have permission to join or leave versions to run a request in a version.
Fixed a problem with potentially mis-acquiring func_code in publisher BeforeTraverse hook.
Fix for issue 683: Image cache manager headers were not sent when an image request returned a 304 (in response to an if-mod-since request).
Made all PluginIndexes and ZCTextIndex use safe_callable, which is aware of extension classes that fill tp_callable but don't define __call__.
Made KeywordIndex be more robust about receiving a value that is not a string or an iterable type.
Fixed incorrect docstring in OFSP/Image help.
Fixed unhelpful signal description.