Merge pull request #115 from zopefoundation/fix-114

fix #114

CHANGES.rst

@@ -4,6 +4,9 @@ Changelog
 2.1.5 (unreleased)
 ------------------
 
+- Fix #114: Problems using ZMI on multi-instance clusters due to instable hash key.
+  (`#114 <https://github.com/zopefoundation/Products.GenericSetup/issues/114>`_)
+
 - Move several tabs to Zope 4+ ZMI-markup standard.  [jensens]
 
 

src/Products/GenericSetup/upgrade.py

@@ -20,6 +20,7 @@
 
 from Products.GenericSetup.interfaces import IUpgradeSteps
 from Products.GenericSetup.registry import GlobalRegistryStorage
+from Products.GenericSetup.utils import _getHash
 
 
 def normalize_version(version):
@@ -123,7 +124,7 @@ class UpgradeEntity(object):
     """
     def __init__(self, title, profile, source, dest, desc, checker=None,
                  sortkey=0):
-        self.id = str(abs(hash('%s%s%s%s' % (title, source, dest, sortkey))))
+        self.id = _getHash(title, source, dest, sortkey)
         self.title = title
         if source == '*':
             source = None

src/Products/GenericSetup/utils.py

@@ -13,6 +13,7 @@
 """ GenericSetup product utilities
 """
 
+import hashlib
 import os
 import sys
 from inspect import getdoc
@@ -1027,3 +1028,10 @@ def _getProductPath(product_name):
                              % product_name)
 
     return product.__path__[0]
+
+
+def _getHash(*args):
+    """return a stable md hash of given string arguments"""
+    base = "".join([str(x) for x in args])
+    hashmd5 = hashlib.md5(base.encode('utf8'))
+    return hashmd5.hexdigest()

src/Products/GenericSetup/zcml.py

@@ -28,6 +28,7 @@
 from .upgrade import UpgradeStep
 from .upgrade import _registerNestedUpgradeStep
 from .upgrade import _registerUpgradeStep
+from .utils import _getHash
 
 
 # genericsetup:registerProfile
@@ -354,8 +355,7 @@ def upgradeStep(self, _context, title, handler,
         step = UpgradeStep(title, self.profile, self.source, self.dest,
                            description, handler, checker, self.sortkey)
         if self.id is None:
-            self.id = str(abs(hash('%s%s%s%s' % (title, self.source, self.dest,
-                                                 self.sortkey))))
+            self.id = _getHash(title, self.source, self.dest, self.sortkey)
         _context.action(
             discriminator=(
                 'upgradeStep', self.profile, self.source, self.dest, handler,
@@ -372,8 +372,7 @@ def upgradeDepends(self, _context, title, description=None,
                               description, import_profile, import_steps,
                               run_deps, purge, checker, self.sortkey)
         if self.id is None:
-            self.id = str(abs(hash('%s%s%s%s' % (title, self.source, self.dest,
-                                                 self.sortkey))))
+            self.id = _getHash(title, self.source, self.dest, self.sortkey)
         _context.action(
             discriminator=(
                 'upgradeDepends', self.profile, self.source, self.dest,