[perl #68654] next::method doesn't see UNIVERSAL

This commit makes next::method retry with UNIVERSAL if it reaches the
end of the MRO list.

2 files changed, 31 insertions, 1 deletions

diff --git a/ext/mro/mro.xs b/ext/mro/mro.xs
index fb28399f77..63befa9d23 100644
--- a/ext/mro/mro.xs
+++ b/ext/mro/mro.xs
@@ -482,6 +482,7 @@ mro__nextcan(...)
     const char *hvname;
     I32 entries;
     struct mro_meta* selfmeta;
+    bool seen_univ = FALSE;
     HV* nmcache;
     I32 i;
   PPCODE:
@@ -612,6 +613,7 @@ mro__nextcan(...)
     /* Now search the remainder of the MRO for the
        same method name as the contextually enclosing
        method */
+   retry:
     if(entries > 0) {
         while (entries--) {
             SV * const linear_sv = *linear_svp++;
@@ -631,6 +633,10 @@ mro__nextcan(...)
 
             assert(curstash);
 
+	    if (!seen_univ && SvCUR(linear_sv) == 9
+	     && strnEQ(SvPV_nolen_const(linear_sv), "UNIVERSAL", 9))
+		seen_univ = TRUE;
+
             gvp = (GV**)hv_fetch(curstash, subname, subname_len, 0);
             if (!gvp) continue;
 
@@ -652,6 +658,14 @@ mro__nextcan(...)
         }
     }
 
+    if (!seen_univ && (selfstash = gv_stashpvn("UNIVERSAL", 9, 0))) {
+	linear_av = S_mro_get_linear_isa_c3(aTHX_ selfstash, 0);
+	linear_svp = AvARRAY(linear_av);
+	entries = AvFILLp(linear_av) + 1;
+	seen_univ = TRUE;
+	goto retry;
+    }
+
     (void)hv_store_ent(nmcache, sv, &PL_sv_undef, 0);
     if(throw_nomethod)
         Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname);
diff --git a/t/mro/next_edgecases.t b/t/mro/next_edgecases.t
index c0da963ede..e77ce7be31 100644
--- a/t/mro/next_edgecases.t
+++ b/t/mro/next_edgecases.t
@@ -5,7 +5,7 @@ use warnings;
 
 BEGIN { chdir 't'; require q(./test.pl); @INC = qw "../lib lib" }
 
-plan(tests => 12);
+plan(tests => 14);
 
 {
 
@@ -93,3 +93,19 @@ plan(tests => 12);
     is($@, '', "->next::can on non-existing package name");
 
 }
+
+# Test next::method with UNIVERSAL methods
+{
+    package UNIVERSAL;
+    sub foo { "foo" }
+    our @ISA = "a";
+    package a;
+    sub bar { "bar" }
+    package M;
+    sub foo { shift->next::method }
+    sub bar { shift->next::method }
+    package main;
+
+    is eval { M->foo }, "foo", 'next::method with implicit UNIVERSAL';
+    is eval { M->bar }, "bar", 'n::m w/superclass of implicit UNIVERSAL';
+}