select() can return undef when defoutgv is set

If PL_defoutgv has been deleted from its stash, select() returns it
as a ref, but if the stash has been freed (even though the gv still
exists), it returns undef.

That makes no sense.

This is one of those nice cases where simplifying the code
fixes a bug.

2 files changed, 13 insertions, 10 deletions

diff --git a/pp_sys.c b/pp_sys.c
index 661e0fca0e..a5fcb00e4d 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -1224,24 +1224,20 @@ PP(pp_select)
     HV *hv;
     GV * const newdefout = (PL_op->op_private > 0) ? (MUTABLE_GV(POPs)) : NULL;
     GV * egv = GvEGVx(PL_defoutgv);
+    GV * const *gvp;
 
     if (!egv)
 	egv = PL_defoutgv;
     hv = isGV_with_GP(egv) ? GvSTASH(egv) : NULL;
-    if (! hv)
-	XPUSHs(&PL_sv_undef);
-    else {
-	GV * const * const gvp =
-	    HvENAME(hv)
+    gvp = hv && HvENAME(hv)
 		? (GV**)hv_fetch(hv, GvNAME(egv), HEK_UTF8(GvNAME_HEK(egv)) ? -GvNAMELEN(egv) : GvNAMELEN(egv), FALSE)
 		: NULL;
-	if (gvp && *gvp == egv) {
+    if (gvp && *gvp == egv) {
 	    gv_efullname4(TARG, PL_defoutgv, NULL, TRUE);
 	    XPUSHTARG;
-	}
-	else {
+    }
+    else {
 	    mXPUSHs(newRV(MUTABLE_SV(egv)));
-	}
     }
 
     if (newdefout) {
diff --git a/t/op/select.t b/t/op/select.t
index 06caf1ddfd..1994dd2131 100644
--- a/t/op/select.t
+++ b/t/op/select.t
@@ -5,7 +5,7 @@ BEGIN {
     require './test.pl';
 }
 
-plan reverse 8;
+plan reverse 9;
 
 
 open my $fh, "test.pl" or die "$0 unfortunately cannot open test.pl: $!";
@@ -25,3 +25,10 @@ $stash = \%foo::;
 *foo:: = *bar::;
 is select, $handle,
     'select returns ref for glob whose stash has been detached';
+
+open thwat::snin, "test.pl" or die "$0 is unable to open test.pl: $!";
+select thwat::snin;
+$handle = \*thwat::snin;
+*thwat:: = *snin::; # gv is now *__ANON__::snin
+is select, $handle,
+    'select returns ref for glob with no stash pointer';