sv.h: Add comment about gv_check and SvIsCOW

So that future refactorings don’t make use of 0x00010000 on
hashes without modifying gv_check to account.

1 files changed, 1 insertions, 0 deletions

diff --git a/sv.h b/sv.h
index c63aeffa28..cd15924ad2 100644
--- a/sv.h
+++ b/sv.h
@@ -363,6 +363,7 @@ perform the upgrade if necessary.  See C<svtype>.
 #define SVpad_NAMELIST	SVp_SCREAM  /* AV is a padnamelist */
 #define SVf_IsCOW	0x00010000  /* copy on write (shared hash key if
 				       SvLEN == 0) */
+				    /* Also used on HVs in gv.c:gv_check */
 #define SVs_PADTMP	0x00020000  /* in use as tmp; only if ! SVs_PADMY */
 #define SVs_PADSTALE	0x00020000  /* lexical has gone out of scope;
 					only valid for SVs_PADMY */