Fix issue with super and forwarding arguments in prism_compile.c

Fixes [Bug #20720]

parse.y

@@ -15132,11 +15132,11 @@ new_args_forward_call(struct parser_params *p, NODE *leading, const YYLTYPE *loc
 #ifndef FORWARD_ARGS_WITH_RUBY2_KEYWORDS
     NODE *kwrest = list_append(p, NEW_LIST(0, loc), NEW_LVAR(idFWD_KWREST, loc));
 #endif
-    rb_node_block_pass_t *block = NEW_BLOCK_PASS(NEW_LVAR(idFWD_BLOCK, loc), loc);
+    rb_node_block_pass_t *block = NEW_BLOCK_PASS(NEW_LVAR(idFWD_BLOCK, loc), argsloc);
     NODE *args = leading ? rest_arg_append(p, leading, rest, argsloc) : NEW_SPLAT(rest, loc);
     block->forwarding = TRUE;
 #ifndef FORWARD_ARGS_WITH_RUBY2_KEYWORDS
-    args = arg_append(p, args, new_hash(p, kwrest, loc), loc);
+    args = arg_append(p, args, new_hash(p, kwrest, loc), argsloc);
 #endif
     return arg_blk_pass(args, block);
 }

prism_compile.c

@@ -1708,7 +1708,7 @@ pm_setup_args_core(const pm_arguments_node_t *arguments_node, const pm_node_t *b
 
                 break;
               }
-              case PM_FORWARDING_ARGUMENTS_NODE: {
+              case PM_FORWARDING_ARGUMENTS_NODE: { // not counted in argc return value
                 if (ISEQ_BODY(ISEQ_BODY(iseq)->local_iseq)->param.flags.forwardable) {
                     *flags |= VM_CALL_FORWARDING;
 
@@ -9628,9 +9628,10 @@ pm_compile_node(rb_iseq_t *iseq, const pm_node_t *node, LINK_ANCHOR *const ret,
         }
         return;
       }
-      case PM_SUPER_NODE: {
+      case PM_SUPER_NODE: { // any super with arguments or `super()`
+        // super()
         // super(foo)
-        // ^^^^^^^^^^
+        // super(...)
         const pm_super_node_t *cast = (const pm_super_node_t *) node;
 
         DECL_ANCHOR(args);
@@ -9649,6 +9650,7 @@ pm_compile_node(rb_iseq_t *iseq, const pm_node_t *node, LINK_ANCHOR *const ret,
         int flags = 0;
         struct rb_callinfo_kwarg *keywords = NULL;
         int argc = pm_setup_args(cast->arguments, cast->block, &flags, &keywords, iseq, ret, scope_node, &location);
+        bool is_forwardable = (cast->arguments != NULL) && PM_NODE_FLAG_P(cast->arguments, PM_ARGUMENTS_NODE_FLAGS_CONTAINS_FORWARDING);
         flags |= VM_CALL_SUPER | VM_CALL_FCALL;
 
         if (cast->block && PM_NODE_TYPE_P(cast->block, PM_BLOCK_NODE)) {
@@ -9668,7 +9670,7 @@ pm_compile_node(rb_iseq_t *iseq, const pm_node_t *node, LINK_ANCHOR *const ret,
         }
 
         PUSH_SEQ(ret, args);
-        if (ISEQ_BODY(ISEQ_BODY(iseq)->local_iseq)->param.flags.forwardable) {
+        if (is_forwardable && ISEQ_BODY(ISEQ_BODY(iseq)->local_iseq)->param.flags.forwardable) {
             flags |= VM_CALL_FORWARDING;
             PUSH_INSN2(ret, location, invokesuperforward, new_callinfo(iseq, 0, argc, flags, keywords, current_block != NULL), current_block);
         }

test/ruby/test_super.rb

@@ -8,6 +8,7 @@ class TestSuper < Test::Unit::TestCase
     def array(*a) a end
     def optional(a = 0) a end
     def keyword(**a) a end
+    def forward(*a) a end
   end
   class Single1 < Base
     def single(*) super end
@@ -63,6 +64,16 @@ class TestSuper < Test::Unit::TestCase
       [x, y]
     end
   end
+  class Forward < Base
+    def forward(...)
+      w = super()
+      x = super
+      y = super(...)
+      a = 1
+      z = super(a, ...)
+      [w, x, y, z]
+    end
+  end
 
   def test_single1
     assert_equal(1, Single1.new.single(1))
@@ -133,6 +144,11 @@ class TestSuper < Test::Unit::TestCase
   def test_keyword2
     assert_equal([{foo: "changed1"}, {foo: "changed2"}], Keyword2.new.keyword)
   end
+  def test_forwardable(...)
+    assert_equal([[],[],[],[1]], Forward.new.forward())
+    assert_equal([[],[1,2],[1,2],[1,1,2]], Forward.new.forward(1,2))
+    assert_equal([[],[:test],[:test],[1,:test]], Forward.new.forward(:test, ...))
+  end
 
   class A
     def tt(aa)