Fix for BUG#10957 "stop instance, issued after flush instances causes IM to crash"

Recommited with post-review fixes

server-tools/instance-manager/instance.h

@@ -41,7 +41,8 @@ public:
   /* send a signal to the instance */
   void kill_instance(int signo);
   int is_crashed();
-  void fork_and_monitor();
+  void set_crash_flag_n_wake_all();
+  Instance_map *Instance::get_map();
 
 public:
   enum { DEFAULT_SHUTDOWN_DELAY= 35 };
@@ -63,7 +64,6 @@ private:
   Instance_map *instance_map;
 
   void  remove_pid();
-  int   launch_and_wait();
 };
 
 #endif /* INCLUDES_MYSQL_INSTANCE_MANAGER_INSTANCE_H */

server-tools/instance-manager/instance_options.cc

@@ -130,6 +130,8 @@ int Instance_options::fill_instance_version()
                             version_option, sizeof(version_option)))
     goto err;
 
+  bzero(result, MAX_VERSION_STRING_LENGTH);
+
   rc= parse_output_and_get_value(cmd.buffer, mysqld_path,
                                  result, MAX_VERSION_STRING_LENGTH,
                                  GET_LINE);