pbx.h: Make ast_state_cb_type take more const.

This eliminates some casts that I made a note saying v10 and above
would no longer need them.

Better late than never :)

Change-Id: I346cdb3032b6478ceb40eb6fe732978b54035572

apps/app_queue.c

@@ -2461,7 +2461,7 @@ static int extensionstate2devicestate(int state)
 	return state;
 }
 
-static int extension_state_cb(char *context, char *exten, struct ast_state_cb_info *info, void *data)
+static int extension_state_cb(const char *context, const char *exten, struct ast_state_cb_info *info, void *data)
 {
 	struct ao2_iterator miter, qiter;
 	struct member *m;

channels/chan_sip.c

@@ -1269,7 +1269,7 @@ static void check_for_nat(const struct ast_sockaddr *them, struct sip_pvt *p);
 
 /*--- Device monitoring and Device/extension state/event handling */
 static int extensionstate_update(const char *context, const char *exten, struct state_notify_data *data, struct sip_pvt *p, int force);
-static int cb_extensionstate(char *context, char *exten, struct ast_state_cb_info *info, void *data);
+static int cb_extensionstate(const char *context, const char *exten, struct ast_state_cb_info *info, void *data);
 static int sip_poke_noanswer(const void *data);
 static int sip_poke_peer(struct sip_peer *peer, int force);
 static void sip_poke_all_peers(void);
@@ -17389,7 +17389,7 @@ static int extensionstate_update(const char *context, const char *exten, struct
 /*! \brief Callback for the devicestate notification (SUBSCRIBE) support subsystem
 \note	If you add an "hint" priority to the extension in the dial plan,
 	you will get notifications on device state changes */
-static int cb_extensionstate(char *context, char *exten, struct ast_state_cb_info *info, void *data)
+static int cb_extensionstate(const char *context, const char *exten, struct ast_state_cb_info *info, void *data)
 {
 	struct sip_pvt *p = data;
 	struct state_notify_data notify_data = {

channels/chan_skinny.c

@@ -1671,7 +1671,7 @@ static struct ast_channel_tech skinny_tech = {
 	.send_digit_end = skinny_senddigit_end,
 };
 
-static int skinny_extensionstate_cb(char *context, char *id, struct ast_state_cb_info *info, void *data);
+static int skinny_extensionstate_cb(const char *context, const char *exten, struct ast_state_cb_info *info, void *data);
 
 static struct skinny_line *skinny_line_alloc(void)
 {
@@ -3413,7 +3413,7 @@ static void transmit_serviceurlstat(struct skinny_device *d, int instance)
 	transmit_response(d, req);
 }
 
-static int skinny_extensionstate_cb(char *context, char *exten, struct ast_state_cb_info *info, void *data)
+static int skinny_extensionstate_cb(const char *context, const char *exten, struct ast_state_cb_info *info, void *data)
 {
 	struct skinny_container *container = data;
 	struct skinny_device *d = NULL;

include/asterisk/pbx.h

@@ -109,7 +109,7 @@ struct ast_state_cb_info {
 };
 
 /*! \brief Typedef for devicestate and hint callbacks */
-typedef int (*ast_state_cb_type)(char *context, char *id, struct ast_state_cb_info *info, void *data);
+typedef int (*ast_state_cb_type)(const char *context, const char *exten, struct ast_state_cb_info *info, void *data);
 
 /*! \brief Typedef for devicestate and hint callback removal indication callback */
 typedef void (*ast_state_cb_destroy_type)(int id, void *data);

main/manager.c

@@ -6765,7 +6765,7 @@ int ast_manager_unregister(const char *action)
 	return 0;
 }
 
-static int manager_state_cb(char *context, char *exten, struct ast_state_cb_info *info, void *data)
+static int manager_state_cb(const char *context, const char *exten, struct ast_state_cb_info *info, void *data)
 {
 	/* Notify managers of change */
 	char hint[512];

main/pbx.c

@@ -3231,8 +3231,7 @@ static int execute_state_callback(ast_state_cb_type cb,
 		info.exten_state = AST_EXTENSION_REMOVED;
 	}
 
-	/* NOTE: The casts will not be needed for v10 and later */
-	res = cb((char *) context, (char *) exten, &info, data);
+	res = cb(context, exten, &info, data);
 
 	return res;
 }

res/res_pjsip_exten_state.c

@@ -191,7 +191,8 @@ static void notify_task_data_destructor(void *obj)
 	ast_free(task_data->exten_state_data.user_agent);
 }
 
-static struct notify_task_data *alloc_notify_task_data(char *exten, struct exten_state_subscription *exten_state_sub,
+static struct notify_task_data *alloc_notify_task_data(const char *exten,
+	struct exten_state_subscription *exten_state_sub,
 	struct ast_state_cb_info *info)
 {
 	struct notify_task_data *task_data =
@@ -270,7 +271,7 @@ static int notify_task(void *obj)
  *
  * Upon state change, send the appropriate notification to the subscriber.
  */
-static int state_changed(char *context, char *exten,
+static int state_changed(const char *context, const char *exten,
 	struct ast_state_cb_info *info, void *data)
 {
 	struct notify_task_data *task_data;