Free bit 7 of GC 'marked' field

Tables were using this bit to indicate their array sizes were real
('isrealasize'), but this bit can be useful for tests. Instead, they
can use bit 7 of their 'flag' field for that purpose. (There are only
six fast-access metamethods.) This 'flag' field only exists in tables,
so this use does not affect other types.

1 files changed, 6 insertions, 1 deletions

diff --git a/ltable.h b/ltable.h
index ebd7f8ec..c0060f4b 100644
--- a/ltable.h
+++ b/ltable.h
@@ -15,7 +15,12 @@
 #define gnext(n)        ((n)->u.next)
 
 
-#define invalidateTMcache(t)    ((t)->flags = 0)
+/*
+** Clear all bits of fast-access metamethods, which means that the table
+** may have any of these metamethods. (First access that fails after the
+** clearing will set the bit again.)
+*/
+#define invalidateTMcache(t)    ((t)->flags &= ~maskflags)
 
 
 /* true when 't' is using 'dummynode' as its hash part */