extconf.rb in patron-0.4.3

- old
+ new

@@ -38,6 +38,8 @@
 
 if CONFIG['CC'] =~ /gcc/
   $CFLAGS << ' -Wall'
 end
 
+$defs.push("-DHAVE_TBR") if have_func('rb_thread_blocking_region')
+
 create_makefile 'patron/session_ext'