my_pthread.c:

  Fix an infinite recursion in my_pthread_mutex_trylock in HP-UX-10.20; the same bug is in the 4.0 tree

mysys/my_pthread.c

@@ -435,7 +435,9 @@ int my_pthread_cond_timedwait(pthread_cond_t *cond,
   pthread_mutex_trylock returns 1 on success, not 0 like
   pthread_mutex_lock
 */
-
+/* We defined pthread_mutex_trylock as a macro in my_pthread.h, we have
+   to undef it here to prevent infinite recursion! */
+#undef pthread_mutex_trylock
 int my_pthread_mutex_trylock(pthread_mutex_t *mutex)
 {
   int error=pthread_mutex_trylock(mutex);