* load.c (load_lock): fix not to delete thread shield twice.

it may break the shield locked by another thread.
  [Bug #7530] [ruby-core:50645]

* test/ruby/test_require.rb: a test for above.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38744 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,11 @@
+Wed Jan  9 09:53:23 2013  Masaki Matsushita  <glass.saga@gmail.com>
+
+	* load.c (load_lock): fix not to delete thread shield twice.
+	  it may break the shield locked by another thread.
+	  [Bug #7530] [ruby-core:50645]
+
+	* test/ruby/test_require.rb: a test for above.
+
 Wed Jan  9 02:13:22 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* include/ruby/ruby.h (RBasic): to be aligned on a VALUE size

load.c

@@ -668,9 +668,6 @@ load_lock(const char *ftptr)
     }
     switch (rb_thread_shield_wait((VALUE)data)) {
       case Qfalse:
-	data = (st_data_t)ftptr;
-	st_delete(loading_tbl, &data, 0);
-	return 0;
       case Qnil:
 	return 0;
     }

test/ruby/test_require.rb

@@ -604,4 +604,25 @@ class TestRequire < Test::Unit::TestCase
       }
     }
   end
+
+  def test_require_with_loaded_features_pop
+    bug7530 = '[ruby-core:50645]'
+    assert_in_out_err([], <<-INPUT, %w(:ok), [], bug7530)
+      THREADS = 2
+      ITERATIONS_PER_THREAD = 1000
+
+      $: << '.'
+      system 'touch __load_path_bench_script__.rb'
+      THREADS.times.map {
+        Thread.new do
+          ITERATIONS_PER_THREAD.times do
+            require '__load_path_bench_script__'
+            $".pop
+          end
+        end
+      }.each(&:join)
+      system 'rm __load_path_bench_script__.rb'
+      p :ok
+    INPUT
+  end
 end