[perl #79824] Don’t cow for sv_mortalcopy call from XS

XS code doing sv_mortalcopy(sv) will expect to get a true copy, and
not a COW ‘copy’.

So make sv_mortalcopy and wrapper around the new sv_mortalcopy_flags
that passes it SV_DO_COW_SVSETSV, which is defined as 0 for XS code.

1 files changed, 2 insertions, 0 deletions

diff --git a/sv.h b/sv.h
index b839a6354c..69a73801b0 100644
--- a/sv.h
+++ b/sv.h
@@ -1805,6 +1805,8 @@ mg.c:1024: warning: left-hand operand of comma expression has no effect
 #define sv_insert(bigstr, offset, len, little, littlelen)		\
 	Perl_sv_insert_flags(aTHX_ (bigstr),(offset), (len), (little),	\
 			     (littlelen), SV_GMAGIC)
+#define sv_mortalcopy(sv) \
+	Perl_sv_mortalcopy_flags(aTHX_ sv, SV_GMAGIC|SV_DO_COW_SVSETSV)
 
 /* Should be named SvCatPVN_utf8_upgrade? */
 #define sv_catpvn_nomg_utf8_upgrade(dsv, sstr, slen, nsv)	\