Merge branch 'ticket27750_034_01_squashed' into maint-0.3.5

changes/bug27750

@@ -0,0 +1,6 @@
+  o Minor bugfixes (connection, relay):
+    - Avoid a wrong BUG() stacktrace in case a closing connection is being held
+      open because the write side is rate limited but not the read side. Now,
+      the connection read side is simply shutdown instead of kept open until tor
+      is able to flush the connection and then fully close it. Fixes bug 27750;
+      bugfix on 0.3.4.1-alpha.

src/core/mainloop/mainloop.c

@@ -1011,23 +1011,18 @@ conn_close_if_marked(int i)
          * busy Libevent loops where we keep ending up here and returning
          * 0 until we are no longer blocked on bandwidth.
          */
-        connection_consider_empty_read_buckets(conn);
         connection_consider_empty_write_buckets(conn);
-
         /* Make sure that consider_empty_buckets really disabled the
          * connection: */
         if (BUG(connection_is_writing(conn))) {
           connection_write_bw_exhausted(conn, true);
         }
-        if (BUG(connection_is_reading(conn))) {
-          /* XXXX+ We should make this code unreachable; if a connection is
-           * marked for close and flushing, there is no point in reading to it
-           * at all. Further, checking at this point is a bit of a hack: it
-           * would make much more sense to react in
-           * connection_handle_read_impl, or to just stop reading in
-           * mark_and_flush */
-          connection_read_bw_exhausted(conn, true/* kludge. */);
-        }
+
+        /* The connection is being held due to write rate limit and thus will
+         * flush its data later. We need to stop reading because this
+         * connection is about to be closed once flushed. It should not
+         * process anything more coming in at this stage. */
+        connection_stop_reading(conn);
       }
       return 0;
     }