2011-04-02  Jon TURNEY  <jon.turney@dronecode.org.uk>

	* thread.cc (semaphore::init): We cannot reliably infer anything from
	the existing contents of sem, so merely warn rather than return EBUSY
	if it looks like we are reinitialising a semaphore.


Index: winsup/cygwin/thread.cc
===================================================================
--- winsup.orig/cygwin/thread.cc	2011-04-02 13:07:03.000000000 +0100
+++ winsup/cygwin/thread.cc	2011-04-02 14:34:39.546875000 +0100
@@ -3198,11 +3198,14 @@
 int
 semaphore::init (sem_t *sem, int pshared, unsigned int value)
 {
-  /* opengroup calls this undefined */
+  /*
+     We can't tell the difference between reinitialising an
+     existing semaphore and initialising a semaphore who's
+     contents happen to be a valid pointer
+   */
   if (is_good_object (sem))
     {
-      set_errno(EBUSY);
-      return -1;
+      paranoid_printf ("potential attempt to reinitialise a semaphore");
     }
 
   if (value > SEM_VALUE_MAX)