bitbake: event: Handle recursive events and the data store better

Events can call each other recursively, e.g. an event handler can call
bb.note which in turn generates another event. If these loop, it
can lead to multiple deletions of 'd' from __builtins__ which
can fail since __builtins__ is global scope.

Add handling to only remove 'd' when we added it and it wasn't already
present.

(Bitbake rev: b45952650ce8f470f124df36185b79e0d3a1783a)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/event.py

@@ -72,7 +72,10 @@ _eventfilter = None
 
 def execute_handler(name, handler, event, d):
     event.data = d
-    __builtins__['d'] = d
+    addedd = False
+    if 'd' not in __builtins__:
+        __builtins__['d'] = d
+        addedd = True
     try:
         ret = handler(event)
     except (bb.parse.SkipRecipe, bb.BBHandledException):
@@ -88,7 +91,8 @@ def execute_handler(name, handler, event, d):
         raise
     finally:
         del event.data
-        del __builtins__['d']
+        if addedd:
+            del __builtins__['d']
 
 def fire_class_handlers(event, d):
     if isinstance(event, logging.LogRecord):