Avoid assigning thread data outside of mutex lock

Patch originally from OpenSUSE:
https://build.opensuse.org/package/show?package=atftp&project=openSUSE%3A12.2

Upstream-Status: Pending

Index: git/tftpd_list.c
===================================================================
--- git.orig/tftpd_list.c	2012-10-24 21:48:47.000000000 -0700
+++ git/tftpd_list.c	2012-10-24 21:52:04.266205076 -0700
@@ -49,11 +49,11 @@
  */
 int tftpd_list_add(struct thread_data *new)
 {
-     struct thread_data *current = thread_data;
+     struct thread_data *current;
      int ret;
 
      pthread_mutex_lock(&thread_list_mutex);
-
+     current = thread_data;
      number_of_thread++;
      
      ret = number_of_thread;
@@ -81,11 +81,13 @@
  */
 int tftpd_list_remove(struct thread_data *old)
 {
-     struct thread_data *current = thread_data;
+     struct thread_data *current;
      int ret;
 
      pthread_mutex_lock(&thread_list_mutex);
 
+     current = thread_data;
+
      number_of_thread--;
      ret = number_of_thread;
     
@@ -137,23 +139,26 @@
                                              struct thread_data *data,
                                              struct client_info *client)
 {
-     struct thread_data *current = thread_data; /* head of the list */
-     struct tftp_opt *tftp_options = data->tftp_options;
+     struct thread_data *current; /* head of the list */
+     struct tftp_opt *tftp_options;
      struct client_info *tmp;
      char options[MAXLEN];
      char string[MAXLEN];
      char *index;
      int len;
 
+     /* lock the whole list before walking it */
+     pthread_mutex_lock(&thread_list_mutex);
+
      *thread = NULL;
 
+     current = thread_data;
+     tftp_options = data->tftp_options;
+
      opt_request_to_string(tftp_options, options, MAXLEN);
      index = strstr(options, "multicast");
      len = (int)index - (int)options;
 
-     /* lock the whole list before walking it */
-     pthread_mutex_lock(&thread_list_mutex);
-
      while (current)
      {
           if (current != data)
@@ -214,9 +219,10 @@
 void tftpd_clientlist_remove(struct thread_data *thread,
                              struct client_info *client)
 {
-     struct client_info *tmp = thread->client_info;
+     struct client_info *tmp;
 
      pthread_mutex_lock(&thread->client_mutex);
+     tmp = thread->client_info;
      while ((tmp->next != client) && (tmp->next != NULL))
           tmp = tmp->next;
      if (tmp->next == NULL)
@@ -231,9 +237,11 @@
 void tftpd_clientlist_free(struct thread_data *thread)
 {
      struct client_info *tmp;
-     struct client_info *head = thread->client_info;
+     struct client_info *head;
 
      pthread_mutex_lock(&thread->client_mutex);
+     head = thread->client_info;
+
      while (head)
      {
           tmp = head;
@@ -250,9 +258,10 @@
                           struct client_info *client,
                           struct sockaddr_storage *sock)
 {
-     struct client_info *head = thread->client_info;
+     struct client_info *head;
 
      pthread_mutex_lock(&thread->client_mutex);
+     head = thread->client_info;
 
      if (client)
      {
@@ -334,10 +343,10 @@
 
 void tftpd_list_kill_threads(void)
 {
-     struct thread_data *current = thread_data; /* head of list */
+     struct thread_data *current; /* head of list */
 
      pthread_mutex_lock(&thread_list_mutex);
-
+     current = thread_data;
 
      while (current != NULL)
      {
Index: git/tftpd_mcast.c
===================================================================
--- git.orig/tftpd_mcast.c	2012-10-24 21:48:47.000000000 -0700
+++ git/tftpd_mcast.c	2012-10-24 21:49:11.570201582 -0700
@@ -51,9 +51,11 @@
  */
 int tftpd_mcast_get_tid(char **addr, short *port)
 {
-     struct tid *current = tid_list;
+     struct tid *current;
 
      pthread_mutex_lock(&mcast_tid_list);
+     current = tid_list;
+
      /* walk the list for a free tid */
      while (current != NULL)
      {
@@ -74,9 +76,11 @@
 
 int tftpd_mcast_free_tid(char *addr, short port)
 {
-     struct tid *current = tid_list;
+     struct tid *current;
 
      pthread_mutex_lock(&mcast_tid_list);
+     current = tid_list;
+
      while (current != NULL)
      {
 	  if ((current->used == 1) && (current->port == port) &&