Revert _part of_ 75c4d5e (re #552) to fix #660

See comments in #660 for rationale and testing.

tl;dr I believe this part of the fix for #552 was erroneous
and I cannot currently prove that it's necessary to fix
the main #552 bug; and I can prove that it is causing #660;
so, revert it is. Plus clarifying the tests that were
'fixed' by #552.

Author: bitprophet

invoke/util.py

@@ -271,8 +271,7 @@ def is_dead(self):
         # NOTE: it seems highly unlikely that a thread could still be
         # is_alive() but also have encountered an exception. But hey. Why not
         # be thorough?
-        alive = self.is_alive() and (self.exc_info is None)
-        return not alive
+        return (not self.is_alive()) and self.exc_info is not None
 
     def __repr__(self):
         # TODO: beef this up more

tests/concurrency.py

@@ -32,14 +32,20 @@ def catches_exceptions(self):
             assert isinstance(wrapper.value, AttributeError)
 
         def exhibits_is_dead_flag(self):
+            # Spin up a thread that will except internally (can't put() on a
+            # None object)
             t = EHThread(target=self.worker, args=[None])
             t.start()
             t.join()
+            # Excepted -> it's dead
             assert t.is_dead
+            # Spin up a happy thread that can exit peacefully (it's not "dead",
+            # though...maybe we should change that terminology)
             t = EHThread(target=self.worker, args=[Queue()])
             t.start()
             t.join()
-            assert t.is_dead
+            # Not dead, just uh...sleeping?
+            assert not t.is_dead
 
     class via_subclassing:
         def setup(self):
@@ -73,11 +79,17 @@ def catches_exceptions(self):
             assert isinstance(wrapper.value, AttributeError)
 
         def exhibits_is_dead_flag(self):
+            # Spin up a thread that will except internally (can't put() on a
+            # None object)
             t = self.klass(queue=None)
             t.start()
             t.join()
+            # Excepted -> it's dead
             assert t.is_dead
+            # Spin up a happy thread that can exit peacefully (it's not "dead",
+            # though...maybe we should change that terminology)
             t = self.klass(queue=Queue())
             t.start()
             t.join()
-            assert t.is_dead
+            # Not dead, just uh...sleeping?
+            assert not t.is_dead