load.c (ruby_init_ext): make idempotent to suppress warnings

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45232 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Sun Mar  2 10:47:58 2014  Eric Wong  <e@80x24.org>
+
+	* load.c (ruby_init_ext): make idempotent to suppress warnings
+
 Sat Mar  1 19:51:42 2014  Tanaka Akira  <akr@fsij.org>
 
 	* lib/open3.rb (Open3.capture3): Ignore Errno::EPIPE for writing

load.c

@@ -1059,10 +1059,13 @@ ruby_init_ext(const char *name, void (*init)(void))
 {
     st_table *loading_tbl = get_loading_table();
 
+    if (rb_provided(name))
+	return;
     if (!loading_tbl) {
 	GET_VM()->loading_table = loading_tbl = st_init_strtable();
     }
     st_update(loading_tbl, (st_data_t)name, register_init_ext, (st_data_t)init);
+    rb_provide(name);
 }
 
 /*