hash.c: compare symbols by identities

* hash.c (rb_any_hash): Symbols are compared by the identities
  always.  [ruby-core:68767] [Bug #11035]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50182 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Wed Apr  8 13:01:06 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* hash.c (rb_any_hash): Symbols are compared by the identities
+	  always.  [ruby-core:68767] [Bug #11035]
+
 Tue Apr  7 10:22:51 2015  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
 
 	* internal.h: fix typo. Patch by @sferik [fix GH-865]

hash.c

@@ -149,6 +149,9 @@ rb_any_hash(VALUE a)
     else if (BUILTIN_TYPE(a) == T_STRING) {
 	hnum = rb_str_hash(a);
     }
+    else if (BUILTIN_TYPE(a) == T_SYMBOL) {
+	hnum = rb_objid_hash((st_index_t)a);
+    }
     else if (BUILTIN_TYPE(a) == T_FLOAT) {
 	return rb_dbl_hash(rb_float_value(a));
     }

test/ruby/test_symbol.rb

@@ -238,4 +238,23 @@ class TestSymbol < Test::Unit::TestCase
       200_000.times { |i| i.to_s.to_sym }
     end;
   end
+
+  def test_hash_redefinition
+    assert_separately([], <<-'end;')
+      bug11035 = '[ruby-core:68767] [Bug #11035]'
+      class Symbol
+        def hash
+          raise
+        end
+      end
+
+      h = {}
+      assert_nothing_raised(RuntimeError, bug11035) {
+        h[:foo] = 1
+      }
+      assert_nothing_raised(RuntimeError, bug11035) {
+        h['bar'.to_sym] = 2
+      }
+    end
+  end;
 end