symbol.c: fix memory leak from global fstr hash

* symbol.c (rb_gc_free_dsymbol): delete from global fstr hash
* test/ruby/test_symbol.rb (test_symbol_fstr_leak): test for bug
  [ruby-core:67268] [Bug #10686]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49090 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Thu Jan  1 11:07:12 2015  Eric Wong  <e@80x24.org>
+
+	* symbol.c (rb_gc_free_dsymbol): delete from global fstr hash
+	* test/ruby/test_symbol.rb (test_symbol_fstr_leak): test for bug
+	  [ruby-core:67268] [Bug #10686]
+
 Thu Jan  1 09:14:21 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* vm_args.c (keyword_hash_p): fix non-symbol keys hash.

symbol.c

@@ -664,6 +664,7 @@ rb_gc_free_dsymbol(VALUE sym)
     if (str) {
 	RSYMBOL(sym)->fstr = 0;
 	unregister_sym(str, sym);
+	rb_hash_delete_entry(global_symbols.dsymbol_fstr_hash, str);
     }
 }
 

test/ruby/test_symbol.rb

@@ -230,4 +230,12 @@ class TestSymbol < Test::Unit::TestCase
     end
     assert_nothing_raised(NoMethodError, bug10259) {obj.send("unagi=".intern, 1)}
   end
+
+  def test_symbol_fstr_leak
+    bug10686 = '[ruby-core:67268] [Bug #10686]'
+    x = 0
+    assert_no_memory_leak([], '', <<-"end;", bug10686)
+      200_000.times { |i| i.to_s.to_sym }
+    end;
+  end
 end