1 files changed, 11 insertions, 11 deletions

diff --git a/bitbake/lib/bb/event.py b/bitbake/lib/bb/event.py
index 3e5718395b..22171a9ca5 100644
--- a/bitbake/lib/bb/event.py
+++ b/bitbake/lib/bb/event.py
@@ -118,7 +118,7 @@ def fire_class_handlers(event, d):
             if _eventfilter:
                 if not _eventfilter(name, handler, event, d):
                     continue
-            if d and not name in (d.getVar("__BBHANDLERS_MC") or []):
+            if d and not name in (d.getVar("__BBHANDLERS_MC") or set()):
                 continue
             execute_handler(name, handler, event, d)
 
@@ -232,15 +232,15 @@ noop = lambda _: None
 def register(name, handler, mask=None, filename=None, lineno=None, data=None):
     """Register an Event handler"""
 
-    if data and data.getVar("BB_CURRENT_MC"):
+    if data is not None and data.getVar("BB_CURRENT_MC"):
         mc = data.getVar("BB_CURRENT_MC")
         name = '%s%s' % (mc.replace('-', '_'), name)
 
     # already registered
     if name in _handlers:
-        if data:
-            bbhands_mc = (data.getVar("__BBHANDLERS_MC") or [])
-            bbhands_mc.append(name)
+        if data is not None:
+            bbhands_mc = (data.getVar("__BBHANDLERS_MC") or set())
+            bbhands_mc.add(name)
             data.setVar("__BBHANDLERS_MC", bbhands_mc)
         return AlreadyRegistered
 
@@ -278,16 +278,16 @@ def register(name, handler, mask=None, filename=None, lineno=None, data=None):
                     _event_handler_map[m] = {}
                 _event_handler_map[m][name] = True
 
-        if data:
-            bbhands_mc = (data.getVar("__BBHANDLERS_MC") or [])
-            bbhands_mc.append(name)
+        if data is not None:
+            bbhands_mc = (data.getVar("__BBHANDLERS_MC") or set())
+            bbhands_mc.add(name)
             data.setVar("__BBHANDLERS_MC", bbhands_mc)
 
         return Registered
 
 def remove(name, handler, data=None):
     """Remove an Event handler"""
-    if data:
+    if data is not None:
         if data.getVar("BB_CURRENT_MC"):
             mc = data.getVar("BB_CURRENT_MC")
             name = '%s%s' % (mc.replace('-', '_'), name)
@@ -299,8 +299,8 @@ def remove(name, handler, data=None):
         if name in _event_handler_map[event]:
             _event_handler_map[event].pop(name)
 
-    if data:
-        bbhands_mc = (data.getVar("__BBHANDLERS_MC") or [])
+    if data is not None:
+        bbhands_mc = (data.getVar("__BBHANDLERS_MC") or set())
         if name in bbhands_mc:
             bbhands_mc.remove(name)
             data.setVar("__BBHANDLERS_MC", bbhands_mc)