Don't insert an entry to loading_tbl if another thread succeed to load.

If rb_thread_shield_wait() returns Qfalse, the file has been successfully
loaded by another thread, so there is no need to insert a new entry into
loading_tbl.  [ruby-core:78464] [Bug #12999]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56985 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

load.c

@@ -745,9 +745,6 @@ load_lock(const char *ftptr)
     }
     switch (rb_thread_shield_wait((VALUE)data)) {
       case Qfalse:
-	data = (st_data_t)ftptr;
-	st_insert(loading_tbl, data, (st_data_t)rb_thread_shield_new());
-	return 0;
       case Qnil:
 	return 0;
     }
@@ -759,7 +756,10 @@ release_thread_shield(st_data_t *key, st_data_t *value, st_data_t done, int exis
 {
     VALUE thread_shield = (VALUE)*value;
     if (!existing) return ST_STOP;
-    if (done ? rb_thread_shield_destroy(thread_shield) : rb_thread_shield_release(thread_shield)) {
+    if (done) {
+	rb_thread_shield_destroy(thread_shield);
+    }
+    else if (rb_thread_shield_release(thread_shield)) {
 	/* still in-use */
 	return ST_CONTINUE;
     }

test/ruby/test_require.rb

@@ -697,9 +697,9 @@ class TestRequire < Test::Unit::TestCase
     bug7530 = '[ruby-core:50645]'
     Tempfile.create(%w'bug-7530- .rb') {|script|
       script.close
-      assert_in_out_err([{"RUBYOPT" => nil}, "-", script.path], <<-INPUT, %w(:ok), [], bug7530, timeout: 20)
+      assert_in_out_err([{"RUBYOPT" => nil}, "-", script.path], <<-INPUT, %w(:ok), [], bug7530, timeout: 40)
         PATH = ARGV.shift
-        THREADS = 2
+        THREADS = 4
         ITERATIONS_PER_THREAD = 1000
 
         THREADS.times.map {