intrpvar.h: Correct comment

This description has been a little faulty for quite some time, not
just because of the last few commits.  Any time pad_free or pad_swipe
is called, that pad slot becomes available and PL_padix is reset.
So ‘max used’ is not accurate.

diff --git a/intrpvar.h b/intrpvar.h
index be61875..db763ad 100644 (file)
--- a/intrpvar.h
+++ b/intrpvar.h
@@ -531,7 +531,8 @@ PERLVAR(I, subline, I32)            /* line this subroutine began on */
 PERLVAR(I, min_intro_pending, I32)     /* start of vars to introduce */
 
 PERLVAR(I, max_intro_pending, I32)     /* end of vars to introduce */
-PERLVAR(I, padix,      I32)            /* max used index in current "register" pad */
+PERLVAR(I, padix,      I32)            /* lowest unused index - 1
+                                          in current "register" pad */
 
 PERLVAR(I, padix_floor,        I32)            /* how low may inner block reset padix */