ERP5Type/patches: prepare for removal of Products.DCWorkflowGraph

Supports the case where Products.DCWorkflowGraph is not present.
Even though we are removing Products.DCWorkflowGraph from the
software release, we don't remove this monkey patch yet, because
this monkey patch also fixed a severe security issue. We keep the
patch for the cases where a recent ERP5 runs on an old SlapOS where
the product is still there.

This change just moves the existing code in a try/except ImportError
block

product/ERP5Type/ZopePatch.py

@@ -85,9 +85,7 @@ from Products.ERP5Type.patches import zopecontenttype
 from Products.ERP5Type.patches import OFSImage
 from Products.ERP5Type.patches import _transaction
 from Products.ERP5Type.patches import default_zpublisher_encoding
-if six.PY2:
-  # DCWorkflowGraph is dead since 2011, so no py3 version
-  from Products.ERP5Type.patches import DCWorkflowGraph
+from Products.ERP5Type.patches import DCWorkflowGraph
 from Products.ERP5Type.patches import SourceCodeEditorZMI
 from Products.ERP5Type.patches import CachingPolicyManager
 from Products.ERP5Type.patches import AcceleratedHTTPCacheManager

product/ERP5Type/patches/DCWorkflowGraph.py

@@ -28,29 +28,35 @@
 #
 ##############################################################################
 
-from AccessControl import ClassSecurityInfo
-from Products.ERP5Type.Globals import InitializeClass
-from Products.ERP5Type import Permissions
-
-# Products.DCWorkflowGraph.config does not check the return value of
-# getenv('PATH'). This fails if PATH is not defined which is the case when
-# running ZEO with SlapOS for example. But, Products.DCWorkflowGraph.__init__
-# imports Products.DCWorkflowGraph.config as a side-effect of importing
-# getGraph, so the only solution is to create a Module which will hide the
-# one from DCWorkflowGraph
-from types import ModuleType
-dc_workflow_config_module = ModuleType('Products.DCWorkflowGraph.config')
-
-import sys
-sys.modules['Products.DCWorkflowGraph.config'] = dc_workflow_config_module
-
-# where is 'pot'?, add your path here
-import os
+try:
+  import Products.DCWorkflowGraph
+except ImportError:
+  pass
+else:
+  # BBB keep Products.DCWorkflowGraph patch for a while as it solves a security issue
+  from AccessControl import ClassSecurityInfo
+  from Products.ERP5Type.Globals import InitializeClass
+  from Products.ERP5Type import Permissions
+
+  # Products.DCWorkflowGraph.config does not check the return value of
+  # getenv('PATH'). This fails if PATH is not defined which is the case when
+  # running ZEO with SlapOS for example. But, Products.DCWorkflowGraph.__init__
+  # imports Products.DCWorkflowGraph.config as a side-effect of importing
+  # getGraph, so the only solution is to create a Module which will hide the
+  # one from DCWorkflowGraph
+  from types import ModuleType
+  dc_workflow_config_module = ModuleType('Products.DCWorkflowGraph.config')
+
+  import sys
+  sys.modules['Products.DCWorkflowGraph.config'] = dc_workflow_config_module
+
+  # where is 'pot'?, add your path here
+  import os
 
-DOT_EXE = 'dot'
-bin_search_path = []
+  DOT_EXE = 'dot'
+  bin_search_path = []
 
-if os.name == 'nt':
+  if os.name == 'nt':
       DOT_EXE = 'dot.exe'
 
       # patch from Joachim Bauch bauch@struktur.de
@@ -71,18 +77,18 @@ if os.name == 'nt':
       except ImportError:
           # win32 may be not installed...
           pass
-else:
+  else:
       # for posix systems
       DOT_EXE = 'dot'
       path = os.getenv("PATH")
       if path is not None:
         bin_search_path = path.split(":")
 
-dc_workflow_config_module.bin_search_path = bin_search_path
-dc_workflow_config_module.DOT_EXE = DOT_EXE
+  dc_workflow_config_module.bin_search_path = bin_search_path
+  dc_workflow_config_module.DOT_EXE = DOT_EXE
 
 
-def getObjectTitle(obj, REQUEST=None):
+  def getObjectTitle(obj, REQUEST=None):
     """
     Get a state/transition title to be displayed in the graph.
 
@@ -125,24 +131,25 @@ def getObjectTitle(obj, REQUEST=None):
 
     return title
 
-from Products.DCWorkflowGraph import DCWorkflowGraph
-DCWorkflowGraph.getObjectTitle = getObjectTitle
+  from Products.DCWorkflowGraph import DCWorkflowGraph
+  DCWorkflowGraph.getObjectTitle = getObjectTitle
 
-from Products.DCWorkflowGraph.config import bin_search_path, DOT_EXE
-from zLOG import LOG, WARNING
-import subprocess
+  from Products.DCWorkflowGraph.config import bin_search_path, DOT_EXE
+  from zLOG import LOG, WARNING
+  import subprocess
 
-def getGraph(self, wf_id="", format="png", REQUEST=None):
+  def getGraph(self, wf_id="", format="png", REQUEST=None):
     """show a workflow as a graph, copy from:
-"OpenFlowEditor":http://www.openflow.it/wwwopenflow/Download/OpenFlowEditor_0_4.tgz
+  "OpenFlowEditor":http://www.openflow.it/wwwopenflow/Download/OpenFlowEditor_0_4.tgz
 
-  Monkey-patched to specify font name and size as 'dot' uses Times font by
-  default which does not support Japanese:
+    Monkey-patched to fix command injection and specify font name and size as 'dot'
+    uses Times font by default which does not support Japanese:
 
     http://www.graphviz.org/doc/fontfaq.txt
 
     Another solution would be to modify fontconfig configuration so that Times
-  match Japanese font or to use Unifont which supports many code points.
+    match Japanese font or to use Unifont which supports many code points - but we
+    don't care, this is obsolete code.
     """
     try:
       pot = self.getPOT(wf_id, REQUEST)
@@ -181,14 +188,14 @@ def getGraph(self, wf_id="", format="png", REQUEST=None):
 
     return result
 
-DCWorkflowGraph.getGraph = getGraph
+  DCWorkflowGraph.getGraph = getGraph
 
-from Products.DCWorkflow.DCWorkflow import DCWorkflowDefinition
-DCWorkflowDefinition.getGraph = getGraph
-DCWorkflowDefinition.getPOT = DCWorkflowGraph.getPOT
+  from Products.DCWorkflow.DCWorkflow import DCWorkflowDefinition
+  DCWorkflowDefinition.getGraph = getGraph
+  DCWorkflowDefinition.getPOT = DCWorkflowGraph.getPOT
 
-security = ClassSecurityInfo()
-security.declareProtected(Permissions.ManagePortal, 'getPOT')
-security.declareProtected(Permissions.ManagePortal, 'getGraph')
-DCWorkflowDefinition.security = security
-InitializeClass(DCWorkflowDefinition)
+  security = ClassSecurityInfo()
+  security.declareProtected(Permissions.ManagePortal, 'getPOT')
+  security.declareProtected(Permissions.ManagePortal, 'getGraph')
+  DCWorkflowDefinition.security = security
+  InitializeClass(DCWorkflowDefinition)