In theory Perl_magic_setbm() should clear SvTAIL() too. In practice,

I don't think that it matters as this routine is never actualy called
because nothing exposes PVBMs to the world so that the world can assign
to them.

p4raw-id: //depot/perl@29541

diff --git a/mg.c b/mg.c
index 450196b..39117e2 100644 (file)
--- a/mg.c
+++ b/mg.c
@@ -2117,6 +2117,7 @@ Perl_magic_setbm(pTHX_ SV *sv, MAGIC *mg)
 {
     PERL_UNUSED_ARG(mg);
     sv_unmagic(sv, PERL_MAGIC_bm);
+    SvTAIL_off(sv);
     SvVALID_off(sv);
     return 0;
 }