struct.c: unique members

* struct.c (struct_make_members_list, rb_struct_s_def): member
  names should be unique. [ruby-core:74971] [Bug #12291]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54612 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,4 +1,7 @@
-Sat Apr 16 09:59:40 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Sat Apr 16 10:00:11 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* struct.c (struct_make_members_list, rb_struct_s_def): member
+	  names should be unique. [ruby-core:74971] [Bug #12291]
 
 	* struct.c (struct_make_members_list): extract making member name
 	  list from char* va_list, with creating symbols without

ext/-test-/struct/duplicate.c

@@ -0,0 +1,24 @@
+#include "ruby.h"
+
+static VALUE
+bug_struct_new_duplicate(VALUE obj, VALUE name, VALUE mem)
+{
+    const char *n = NIL_P(name) ? 0 : StringValueCStr(name);
+    const char *m = StringValueCStr(mem);
+    return rb_struct_define(n, m, m, NULL);
+}
+
+static VALUE
+bug_struct_new_duplicate_under(VALUE obj, VALUE name, VALUE mem)
+{
+    const char *n = StringValueCStr(name);
+    const char *m = StringValueCStr(mem);
+    return rb_struct_define_under(obj, n, m, m, NULL);
+}
+
+void
+Init_duplicate(VALUE klass)
+{
+    rb_define_singleton_method(klass, "new_duplicate", bug_struct_new_duplicate, 2);
+    rb_define_singleton_method(klass, "new_duplicate_under", bug_struct_new_duplicate_under, 2);
+}

struct.c

@@ -334,12 +334,19 @@ static VALUE
 struct_make_members_list(va_list ar)
 {
     char *mem;
-    VALUE ary = rb_ary_tmp_new(0);
+    VALUE ary, list = rb_ident_hash_new();
+    st_table *tbl = RHASH_TBL(list);
 
+    RBASIC_CLEAR_CLASS(list);
     while ((mem = va_arg(ar, char*)) != 0) {
 	VALUE sym = rb_sym_intern_ascii_cstr(mem);
-	rb_ary_push(ary, sym);
+	if (st_insert(tbl, sym, Qtrue)) {
+	    rb_raise(rb_eArgError, "duplicate member: %s", mem);
+	}
     }
+    ary = rb_hash_keys(list);
+    st_clear(tbl);
+    RBASIC_CLEAR_CLASS(ary);
     OBJ_FREEZE_RAW(ary);
     return ary;
 }
@@ -482,7 +489,7 @@ rb_struct_s_def(int argc, VALUE *argv, VALUE klass)
     VALUE name, rest;
     long i;
     VALUE st;
-    ID id;
+    st_table *tbl;
 
     rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS);
     name = argv[0];
@@ -493,12 +500,18 @@ rb_struct_s_def(int argc, VALUE *argv, VALUE klass)
 	--argc;
 	++argv;
     }
-    rest = rb_ary_tmp_new(argc);
+    rest = rb_ident_hash_new();
+    RBASIC_CLEAR_CLASS(rest);
+    tbl = RHASH_TBL(rest);
     for (i=0; i<argc; i++) {
-	id = rb_to_id(argv[i]);
-	RARRAY_ASET(rest, i, ID2SYM(id));
-	rb_ary_set_len(rest, i+1);
+	VALUE mem = rb_to_symbol(argv[i]);
+	if (st_insert(tbl, mem, Qtrue)) {
+	    rb_raise(rb_eArgError, "duplicate member: %"PRIsVALUE, mem);
+	}
     }
+    rest = rb_hash_keys(rest);
+    st_clear(tbl);
+    RBASIC_CLEAR_CLASS(rest);
     OBJ_FREEZE_RAW(rest);
     if (NIL_P(name)) {
 	st = anonymous_struct(klass);

test/-ext-/struct/test_duplicate.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: false
+require 'test/unit'
+require "-test-/struct"
+
+class Bug::Struct::Test_Duplicate < Test::Unit::TestCase
+  def test_new_dupilicate
+    bug12291 = '[ruby-core:74971] [Bug #12291]'
+    assert_raise_with_message(ArgumentError, /duplicate member/, bug12291) {
+      Bug::Struct.new_duplicate(nil, "a")
+    }
+    assert_raise_with_message(ArgumentError, /duplicate member/, bug12291) {
+      Bug::Struct.new_duplicate("X", "a")
+    }
+  end
+
+  def test_new_dupilicate_under
+    bug12291 = '[ruby-core:74971] [Bug #12291]'
+    assert_raise_with_message(ArgumentError, /duplicate member/, bug12291) {
+      Bug::Struct.new_duplicate_under("x", "a")
+    }
+  end
+end

test/ruby/test_struct.rb

@@ -367,6 +367,13 @@ module TestStruct
     assert_nil(o.dig(:b, 0))
   end
 
+  def test_new_dupilicate
+    bug12291 = '[ruby-core:74971] [Bug #12291]'
+    assert_raise_with_message(ArgumentError, /duplicate member/, bug12291) {
+      @Struct.new(:a, :a)
+    }
+  end
+
   class TopStruct < Test::Unit::TestCase
     include TestStruct