[perl #115440] Fix various leaks with fatal FETCH

Various pieces of code were creating an SV and then assigning to it
from a value that might be magical.  If the source scalar is magical,
it could die when magic is called, leaking the scalar that would have
been assigned to.

So we call get-magic before creating the new scalar, and then use a
non-magical assignment.

Also, anonhash and anonlist were doing nothing to protect the aggre-
gate if an argument should die on FETCH, resulting in a leak.

1 files changed, 4 insertions, 2 deletions

diff --git a/mathoms.c b/mathoms.c
index e8d81054a0..e19b24c638 100644
--- a/mathoms.c
+++ b/mathoms.c
@@ -804,8 +804,10 @@ Perl_save_list(pTHX_ register SV **sarg, I32 maxsarg)
     PERL_ARGS_ASSERT_SAVE_LIST;
 
     for (i = 1; i <= maxsarg; i++) {
-	SV * const sv = newSV(0);
-	sv_setsv(sv,sarg[i]);
+	SV *sv;
+	SvGETMAGIC(sarg[i]);
+	sv = newSV(0);
+	sv_setsv_nomg(sv,sarg[i]);
 	SSCHECK(3);
 	SSPUSHPTR(sarg[i]);		/* remember the pointer */
 	SSPUSHPTR(sv);			/* remember the value */