diff -r edf29f9c15f0 -r dc4d2cd3aa3e mercurial/hgweb/server.py
--- a/mercurial/hgweb/server.py	Tue Nov 25 19:40:54 2014 -0800
+++ b/mercurial/hgweb/server.py	Fri Nov 28 10:59:02 2014 -0800
@@ -81,6 +81,7 @@
         except Exception:
             self._start_response("500 Internal Server Error", [])
             self._write("Internal Server Error")
+            self._done()
             tb = "".join(traceback.format_exception(*sys.exc_info()))
             self.log_error("Exception happened during processing "
                            "request '%s':\n%s", self.path, tb)