Fix post mortem debugger for exception when yielding items or in close().

Author: GrahamDumpleton

docs/release-notes/version-4.4.20.rst

@@ -9,3 +9,10 @@ Version 4.4.20 of mod_wsgi can be obtained from:
 For details on the availability of Windows binaries see:
 
   https://github.com/GrahamDumpleton/mod_wsgi/tree/master/win32
+
+Bugs Fixed
+----------
+
+1. Post mortem debugger would fail if the exception was raised during
+yielding of items from a WSGI application, or inside of any ``close()``
+callable of an iterator returned from the WSGI application.

src/server/__init__.py

@@ -1117,15 +1117,15 @@ def __iter__(self):
             for item in self.generator:
                 yield item
         except Exception:
-            self.debug_exception()
+            self.run_post_mortem()
             raise
 
     def close(self):
         try:
             if hasattr(self.generator, 'close'):
                 return self.generator.close()
         except Exception:
-            self.debug_exception()
+            self.run_post_mortem()
             raise
 
 class RequestRecorder(object):