pp_ctl.c - teach module_true how to deal with blocked requires

If require encounters an @INC hook that blocks the require it
ends up with a STUB node as the optree for the LEAVEEVAL. This was
causing the module_true logic to segfault. Guarding against the
OP_STUB node fixes the problem.

This affected the tests for IO::Socket::SSL. Thanks to Graham
Knopp for the reduced case, and James Keenan for reporting it
in https://github.com/Perl/perl5/issues/20468.

This should fix the problem.

1 files changed, 8 insertions, 1 deletions

diff --git a/t/op/require_errors.t b/t/op/require_errors.t
index f80aebd422..1e86fbb719 100644
--- a/t/op/require_errors.t
+++ b/t/op/require_errors.t
@@ -9,7 +9,7 @@ BEGIN {
 use strict;
 use warnings;
 
-plan(tests => 57);
+plan(tests => 58);
 
 my $nonfile = tempfile();
 
@@ -283,3 +283,10 @@ like $@, qr/^Can't locate \Q$nonsearch\E at/,
        "check the second attempt also fails");
     like $@, qr/Attempt to reload/, "check we failed for the right reason";
 }
+
+{
+    fresh_perl_like(
+        'unshift @INC, sub { sub { 0 } }; require "asdasd";',
+        qr/asdasd did not return a true value/,
+        { }, '@INC hook blocks do not cause segfault');
+}