Fix SF bug # 1030941. In _parsegen(), in the clause where we're

capturing_preamble but we found a StartBoundaryNotFoundDefect, we need to
consume all lines from the current position to the EOF, which we'll set as the
epilogue of the current message.  If we're not at EOF when we return from
here, the outer message's capturing_preamble assertion will fail.

Lib/email/FeedParser.py

@@ -309,8 +309,6 @@ class FeedParser:
                             if eolmo:
                                 preamble[-1] = lastline[:-len(eolmo.group(0))]
                             self._cur.preamble = EMPTYSTRING.join(preamble)
-                        #import pdb ; pdb.set_trace()
-                        # See SF bug #1030941
                         capturing_preamble = False
                         self._input.unreadline(line)
                         continue
@@ -367,10 +365,16 @@ class FeedParser:
             # We've seen either the EOF or the end boundary.  If we're still
             # capturing the preamble, we never saw the start boundary.  Note
             # that as a defect and store the captured text as the payload.
-            # Otherwise everything from here to the EOF is epilogue.
+            # Everything from here to the EOF is epilogue.
             if capturing_preamble:
                 self._cur.defects.append(Errors.StartBoundaryNotFoundDefect())
                 self._cur.set_payload(EMPTYSTRING.join(preamble))
+                epilogue = []
+                for line in self._input:
+                    if line is NeedMoreData:
+                        yield NeedMoreData
+                        continue
+                self._cur.epilogue = EMPTYSTRING.join(epilogue)
                 return
             # If the end boundary ended in a newline, we'll need to make sure
             # the epilogue isn't None