Bug #55426 mysqltest crashes when trying to unlock not acquired mutex

Bug #55546 mysqltest fails to create a new thread on HPUX
Missing call to pthread_join(), in embedded mode
This independently solves both problems, see 55426 for details.
Addendum: cannot test against a pthread_t, adds boolean flag instead

client/mysqltest.cc

@@ -242,7 +242,9 @@ struct st_connection
   int cur_query_len;
   pthread_mutex_t mutex;
   pthread_cond_t cond;
+  pthread_t tid;
   int query_done;
+  my_bool has_thread;
 #endif /*EMBEDDED_LIBRARY*/
 };
 
@@ -733,8 +735,6 @@ pthread_handler_t send_one_query(void *arg)
 static int do_send_query(struct st_connection *cn, const char *q, int q_len,
                          int flags)
 {
-  pthread_t tid;
-
   if (flags & QUERY_REAP_FLAG)
     return mysql_send_query(&cn->mysql, q, q_len);
 
@@ -745,9 +745,10 @@ static int do_send_query(struct st_connection *cn, const char *q, int q_len,
   cn->cur_query= q;
   cn->cur_query_len= q_len;
   cn->query_done= 0;
-  if (pthread_create(&tid, &cn_thd_attrib, send_one_query, (void*)cn))
+  if (pthread_create(&cn->tid, &cn_thd_attrib, send_one_query, (void*)cn))
     die("Cannot start new thread for query");
 
+  cn->has_thread= TRUE;
   return 0;
 }
 
@@ -760,6 +761,11 @@ static void wait_query_thread_end(struct st_connection *con)
       pthread_cond_wait(&con->cond, &con->mutex);
     pthread_mutex_unlock(&con->mutex);
   }
+  if (con->has_thread)
+  {
+    pthread_join(con->tid, NULL);
+    con->has_thread= FALSE;
+  }
 }
 
 #else /*EMBEDDED_LIBRARY*/
@@ -5187,6 +5193,7 @@ void do_connect(struct st_command *command)
 
 #ifdef EMBEDDED_LIBRARY
   con_slot->query_done= 1;
+  con_slot->has_thread= FALSE;
 #endif
   if (!mysql_init(&con_slot->mysql))
     die("Failed on mysql_init()");