corrected bug in DestroyHandler

gof/destroyhandler.py

@@ -156,7 +156,7 @@ class DestroyHandlerHelper2(toolbox.Bookkeeper):
         self.debug_all_apps.remove(app)
 
         #UPDATE self.clients
-        for i, input in enumerate(app.inputs):
+        for i, input in enumerate(set(app.inputs)):
             del self.clients[input][app]
 
         if getattr(app.op, 'destroy_map', {}):

gof/env.py

@@ -227,6 +227,7 @@ class Env(utils.object2):
         For each feature that has a 'on_change_input' method, calls:
           feature.on_change_input(env, node, i, old_r, new_r)
         """
+        # TODO: ERROR HANDLING FOR LISTENERS (should it complete the change or revert it?)
         if node == 'output':
             r = self.outputs[i]
             if not r.type == new_r.type:

gof/toolbox.py

 
 from functools import partial
 import graph
+import sys
 
 
 class AlreadyThere(Exception):
@@ -97,7 +98,12 @@ class ReplaceValidate(History, Validator):
     def replace_all_validate(self, env, replacements):
         chk = env.checkpoint()
         for r, new_r in replacements:
-            env.replace(r, new_r)
+            try:
+                env.replace(r, new_r)
+            except Exception, e:
+                print >>sys.stderr, "<<!! BUG IN ENV.REPLACE OR A LISTENER !!>>", type(e), e
+                env.revert(chk) # this might fail; env.replace should never raise an exception (it kinda needs better internal error handling)
+                raise
         try:
             env.validate()
         except: