[perl #125115] don't create file GLOB(...) when dupping a closed handle

doio.c

@@ -438,8 +438,11 @@ Perl_do_open6(pTHX_ GV *gv, const char *oname, STRLEN len,
 			    else if (IoTYPE(thatio) == IoTYPE_SOCKET)
 				IoTYPE(io) = IoTYPE_SOCKET;
 			}
-			else
-			    wanted_fd = -1;
+                        else {
+                            SETERRNO(EBADF, RMS_IFI);
+                            fp = NULL;
+                            goto say_false;
+                        }
 		    }
 		    if (!num_svs)
 			type = NULL;

t/io/open.t

@@ -10,7 +10,7 @@ $|  = 1;
 use warnings;
 use Config;
 
-plan tests => 153;
+plan tests => 156;
 
 my $Perl = which_perl();
 
@@ -476,6 +476,14 @@ pass("no crash when open autovivifies glob in freed package");
     is((stat $temp)[9], $final_mtime, "nothing changes its mtime");
 }
 
+# [perl #125115] Dup to closed filehandle creates file named GLOB(0x...)
+{
+    ok(open(my $fh, "<", "TEST"), "open a handle");
+    ok(close $fh, "and close it again");
+    ok(!open(my $fh2,  ">&", $fh), "should fail to dup the closed handle");
+    # clean up if we failed
+    unlink "$fh";
+}
 
 package OverloadTest;
 use overload '""' => sub { ${$_[0]} };