From fa48a26d886d86469a0075d91d152252e9fc0c8c Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Mon, 24 Feb 2020 15:33:50 +0900
Subject: Fixed symbol misused as ID

`rb_funcallv_public` and `rb_respond_to` require an `ID`, not a
`Symbol`.  [Bug #16649]

(cherry picked from commit 8b6e2685a4b7c7de905f7ed60c02ef85e0724754)
---
 common.mk                   | 1 +
 test/ruby/test_transcode.rb | 8 ++++++++
 transcode.c                 | 8 ++++----
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/common.mk b/common.mk
index 3706aeb4ce..fd14ab6688 100644
--- a/common.mk
+++ b/common.mk
@@ -3037,6 +3037,7 @@ transcode.$(OBJEXT): {$(VPATH)}assert.h
 transcode.$(OBJEXT): {$(VPATH)}config.h
 transcode.$(OBJEXT): {$(VPATH)}defines.h
 transcode.$(OBJEXT): {$(VPATH)}encoding.h
+transcode.$(OBJEXT): {$(VPATH)}id.h
 transcode.$(OBJEXT): {$(VPATH)}intern.h
 transcode.$(OBJEXT): {$(VPATH)}internal.h
 transcode.$(OBJEXT): {$(VPATH)}missing.h
diff --git a/test/ruby/test_transcode.rb b/test/ruby/test_transcode.rb
index f405877dd5..1f4c623acb 100644
--- a/test/ruby/test_transcode.rb
+++ b/test/ruby/test_transcode.rb
@@ -2183,6 +2183,14 @@ class TestTranscode < Test::Unit::TestCase
     assert_equal("U+3042", "\u{3042}".encode("US-ASCII", fallback: fallback.method(:escape)))
   end
 
+  def test_fallback_aref
+    fallback = Object.new
+    def fallback.[](x)
+      "U+%.4X" % x.unpack("U")
+    end
+    assert_equal("U+3042", "\u{3042}".encode("US-ASCII", fallback: fallback))
+  end
+
   bug8940 = '[ruby-core:57318] [Bug #8940]'
   %w[UTF-32 UTF-16].each do |enc|
     define_method("test_pseudo_encoding_inspect(#{enc})") do
diff --git a/transcode.c b/transcode.c
index aeab90f9e6..1c9cc01f36 100644
--- a/transcode.c
+++ b/transcode.c
@@ -13,6 +13,7 @@
 #include "internal.h"
 #include "transcode_data.h"
 #include <ctype.h>
+#include "id.h"
 
 #define ENABLE_ECONV_NEWLINE_OPTION 1
 
@@ -23,7 +24,7 @@ static VALUE rb_eConverterNotFoundError;
 
 VALUE rb_cEncodingConverter;
 
-static VALUE sym_invalid, sym_undef, sym_replace, sym_fallback, sym_aref;
+static VALUE sym_invalid, sym_undef, sym_replace, sym_fallback;
 static VALUE sym_xml, sym_text, sym_attr;
 static VALUE sym_universal_newline;
 static VALUE sym_crlf_newline;
@@ -2241,7 +2242,7 @@ method_fallback(VALUE fallback, VALUE c)
 static VALUE
 aref_fallback(VALUE fallback, VALUE c)
 {
-    return rb_funcall3(fallback, sym_aref, 1, &c);
+    return rb_funcallv_public(fallback, idAREF, 1, &c);
 }
 
 static void
@@ -2535,7 +2536,7 @@ rb_econv_prepare_options(VALUE opthash, VALUE *opts, int ecflags)
     if (!NIL_P(v)) {
 	VALUE h = rb_check_hash_type(v);
 	if (NIL_P(h)
-	    ? (rb_obj_is_proc(v) || rb_obj_is_method(v) || rb_respond_to(v, sym_aref))
+	    ? (rb_obj_is_proc(v) || rb_obj_is_method(v) || rb_respond_to(v, idAREF))
 	    : (v = h, 1)) {
 	    if (NIL_P(newhash))
 		newhash = rb_hash_new();
@@ -4408,7 +4409,6 @@ Init_transcode(void)
     sym_undef = ID2SYM(rb_intern("undef"));
     sym_replace = ID2SYM(rb_intern("replace"));
     sym_fallback = ID2SYM(rb_intern("fallback"));
-    sym_aref = ID2SYM(rb_intern("[]"));
     sym_xml = ID2SYM(rb_intern("xml"));
     sym_text = ID2SYM(rb_intern("text"));
     sym_attr = ID2SYM(rb_intern("attr"));
-- 
cgit v1.2.3