allow AUTOLOAD for the INC method of objects in @INC

This matches the behaviour in 5.36.

This does not allow AUTOLOAD for INCDIR, since if there is an AUTOLOAD
the check for INC would have already succeeded.

Fixes #20665

2 files changed, 23 insertions, 2 deletions

diff --git a/pp_ctl.c b/pp_ctl.c
index 4ffd59bbbe..193e328088 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -4338,10 +4338,11 @@ S_require_file(pTHX_ SV *sv)
                          * call the method.
                          */
                         HV *pkg = SvSTASH(SvRV(loader));
-                        GV * gv = gv_fetchmethod_pvn_flags(pkg, "INC", 3, 0);
+                        GV * gv = gv_fetchmethod_pvn_flags(pkg, "INC", 3, GV_AUTOLOAD);
                         if (gv && isGV(gv)) {
                             method = "INC";
                         } else {
+                            /* no point to autoload here, it would have been found above */
                             gv = gv_fetchmethod_pvn_flags(pkg, "INCDIR", 6, 0);
                             if (gv && isGV(gv)) {
                                 method = "INCDIR";
diff --git a/t/op/inccode.t b/t/op/inccode.t
index 26b6993f29..ef124f3eb3 100644
--- a/t/op/inccode.t
+++ b/t/op/inccode.t
@@ -21,7 +21,7 @@ unless (is_miniperl()) {
 
 use strict;
 
-plan(tests => 68 + !is_miniperl() * (4 + 14 * $can_fork));
+plan(tests => 71 + !is_miniperl() * (4 + 14 * $can_fork));
 
 sub get_temp_fh {
     my $f = tempfile();
@@ -179,6 +179,26 @@ is( $INC{'Toto.pm'}, 'xyz',	   '  val Toto.pm is correct in %INC' );
 
 pop @INC;
 
+{
+    my $autoloaded;
+    package AutoInc {
+        sub AUTOLOAD {
+            my ($self, $filename) = @_;
+            $autoloaded = our $AUTOLOAD;
+            return ::get_temp_fh($filename);
+        }
+        sub DESTROY {}
+    }
+
+    push @INC, bless {}, "AutoInc";
+    $evalret = eval { require Quux3; 1 };
+    ok($evalret, "require Quux3 via AUTOLOADed INC");
+    ok(exists $INC{"Quux3.pm"}, "Quux3 in %INC");
+    is($autoloaded, "AutoInc::INC", "AUTOLOAD was called for INC");
+
+    pop @INC;
+}
+
 push @INC, sub {
     my ($self, $filename) = @_;
     if ($filename eq 'abc.pl') {