1 files changed, 8 insertions, 6 deletions

diff --git a/src/lua/lstate.h b/src/lua/lstate.h
index 697d73b..1b6bcdf 100644
--- a/src/lua/lstate.h
+++ b/src/lua/lstate.h
@@ -63,7 +63,7 @@
 ** can become gray have such a field. The field is not the same
 ** in all objects, but it always has this name.)  Any gray object
 ** must belong to one of these lists, and all objects in these lists
-** must be gray (with one exception explained below):
+** must be gray (with two exceptions explained below):
 **
 ** 'gray': regular gray objects, still waiting to be visited.
 ** 'grayagain': objects that must be revisited at the atomic phase.
@@ -75,11 +75,13 @@
 ** 'ephemeron': ephemeron tables with white->white entries;
 ** 'allweak': tables with weak keys and/or weak values to be cleared.
 **
-** The exception to that "gray rule" is the TOUCHED2 objects in
-** generational mode. Those objects stay in a gray list (because they
-** must be visited again at the end of the cycle), but they are marked
-** black (because assignments to them must activate barriers, to move
-** them back to TOUCHED1).
+** The exceptions to that "gray rule" are:
+** - TOUCHED2 objects in generational mode stay in a gray list (because
+** they must be visited again at the end of the cycle), but they are
+** marked black because assignments to them must activate barriers (to
+** move them back to TOUCHED1).
+** - Open upvales are kept gray to avoid barriers, but they stay out
+** of gray lists. (They don't even have a 'gclist' field.)
 */