diff -p -up perl-5.10.0/sv.c.pix perl-5.10.0/sv.c
--- perl-5.10.0/sv.c.pix	2007-12-18 11:47:08.000000000 +0100
+++ perl-5.10.0/sv.c	2008-04-01 15:08:10.000000000 +0200
@@ -5091,6 +5091,17 @@ Perl_sv_clear(pTHX_ register SV *sv)
     assert(sv);
     assert(SvREFCNT(sv) == 0);
 
+    if (type == SVTYPEMASK) {
+	/* in some bad cases, scalar is freed a second time,
+	   resulting in a segfault (mdvbz#34505) in mg_free(sv) below.
+
+	   perl HEAD has an assert (http://public.activestate.com/cgi-bin/perlbrowse/p/32788),
+	   but since we can't reproduce and it's seems hard to fix those cases,
+	   (as http://rt.perl.org/rt3/Public/Bug/Display.html?id=50142 seems to say ??)
+	   we need to workaround... */
+	return;
+    }
+
     if (type <= SVt_IV) {
 	/* See the comment in sv.h about the collusion between this early
 	   return and the overloading of the NULL and IV slots in the size