Raise an AssertionError in CompositeTask._wait() if it's detected that

self._current_task hasn't been properly updated after calling wait on
it.

svn path=/main/trunk/; revision=10987

1 files changed, 7 insertions, 1 deletions

diff --git a/pym/_emerge/__init__.py b/pym/_emerge/__init__.py
index f0a0a687c..c5d6c402f 100644
--- a/pym/_emerge/__init__.py
+++ b/pym/_emerge/__init__.py
@@ -1582,9 +1582,15 @@ class CompositeTask(AsynchronousTask):
 		prev = None
 		while True:
 			task = self._current_task
-			if task is None or task is prev:
+			if task is None:
 				# don't wait for the same task more than once
 				break
+			if task is prev:
+				# Before the task.wait() method returned, an exit
+				# listener should have set self._current_task to either
+				# a different task or None. Something is wrong.
+				raise AssertionError("self._current_task has not " + \
+					"changed since calling wait", self, task)
 			task.wait()
 			prev = task