Added internal awareness of active script instances

Fixes the following issues:
- donpcevent could cause a crash when used to a event of the same npc
- input/other-dialog-interactions could cause a crash when sending data to a disabled-fakenpc-id'd.
Special Thanks to Haruna, ossi0110.

Signed-off-by: shennetsind <ind@henn.et>

3 files changed, 32 insertions, 12 deletions

diff --git a/src/map/npc.c b/src/map/npc.c
index 7933f6d43..f77359b5f 100644
--- a/src/map/npc.c
+++ b/src/map/npc.c
@@ -1185,21 +1185,21 @@ int npc_click(struct map_session_data* sd, struct npc_data* nd)
 /*==========================================
  *
  *------------------------------------------*/
-int npc_scriptcont(struct map_session_data* sd, int id, bool closing)
-{
+int npc_scriptcont(struct map_session_data* sd, int id, bool closing) {
+	struct block_list *target = map->id2bl(id);
 	nullpo_retr(1, sd);
 
 	if( id != sd->npc_id ){
 		TBL_NPC* nd_sd=(TBL_NPC*)map->id2bl(sd->npc_id);
-		TBL_NPC* nd=(TBL_NPC*)map->id2bl(id);
+		TBL_NPC* nd = BL_CAST(BL_NPC, target);
 		ShowDebug("npc_scriptcont: %s (sd->npc_id=%d) is not %s (id=%d).\n",
 			nd_sd?(char*)nd_sd->name:"'Unknown NPC'", (int)sd->npc_id,
 		  	nd?(char*)nd->name:"'Unknown NPC'", (int)id);
 		return 1;
 	}
-
+	
 	if(id != npc->fake_nd->bl.id) { // Not item script
-		if ((npc->checknear(sd,map->id2bl(id))) == NULL){
+		if ((npc->checknear(sd,target)) == NULL){
 			ShowWarning("npc_scriptcont: failed npc->checknear test.\n");
 			return 1;
 		}
@@ -1219,7 +1219,10 @@ int npc_scriptcont(struct map_session_data* sd, int id, bool closing)
 	 **/
 	if( sd->progressbar.npc_id && DIFF_TICK(sd->progressbar.timeout,timer->gettick()) > 0 )
 		return 1;
-
+	
+	if( !sd->st )
+		return 1;
+	
 	if( closing && sd->st->state == CLOSE )
 		sd->st->state = END;
 
@@ -2226,7 +2229,6 @@ int npc_unload(struct npc_data* nd, bool single) {
 			aFree(nd->u.scr.timer_event);
 		if (nd->src_id == 0) {
 			if(nd->u.scr.script) {
-				script->stop_instances(nd->u.scr.script);
 				script->free_code(nd->u.scr.script);
 				nd->u.scr.script = NULL;
 			}
diff --git a/src/map/script.c b/src/map/script.c
index bba771a3c..fca87a81d 100644
--- a/src/map/script.c
+++ b/src/map/script.c
@@ -3208,9 +3208,8 @@ void script_free_vars(struct DBMap* var_storage) {
 
 void script_free_code(struct script_code* code)
 {
-	script->free_vars(code->local.vars);
-	if( code->local.arrays )
-		code->local.arrays->destroy(code->local.arrays,script->array_free_db);
+	if( code->instances )
+		script->stop_instances(code);
 	aFree( code->script_buf );
 	aFree( code );
 }
@@ -3242,6 +3241,13 @@ struct script_state* script_alloc_state(struct script_code* rootscript, int pos,
 	st->oid = oid;
 	st->sleep.timer = INVALID_TIMER;
 	st->npc_item_flag = battle_config.item_enabled_npc;
+	
+	if( st->script->instances != USHRT_MAX )
+		st->script->instances++;
+	else {
+		struct npc_data *nd = map->id2nd(oid);
+		ShowError("over 65k instances of '%s' script are being run\n",nd ? nd->name : "unknown");
+	}
 
 	if( !st->script->local.vars )
 		st->script->local.vars = i64db_alloc(DB_OPT_RELEASE_DATA);
@@ -3259,9 +3265,20 @@ struct script_state* script_alloc_state(struct script_code* rootscript, int pos,
 /// @param st Script state
 void script_free_state(struct script_state* st) {
 	if( idb_exists(script->st_db,st->id) ) {
+		struct map_session_data *sd = st->rid ? map->id2sd(st->rid) : NULL;
+		
 		if(st->bk_st) {// backup was not restored
 			ShowDebug("script_free_state: Previous script state lost (rid=%d, oid=%d, state=%d, bk_npcid=%d).\n", st->bk_st->rid, st->bk_st->oid, st->bk_st->state, st->bk_npcid);
 		}
+		
+		if(sd && sd->st == st) { //Current script is aborted.
+			if(sd->state.using_fake_npc){
+				clif->clearunit_single(sd->npc_id, CLR_OUTSIGHT, sd->fd);
+				sd->state.using_fake_npc = 0;
+			}
+			sd->st = NULL;
+			sd->npc_id = 0;
+		}
 
 		if( st->sleep.timer != INVALID_TIMER )
 			timer->delete(st->sleep.timer, script->run_timer);
@@ -3274,7 +3291,7 @@ void script_free_state(struct script_state* st) {
 			ers_free(script->stack_ers, st->stack);
 			st->stack = NULL;
 		}
-		if( st->script ) {
+		if( st->script && st->script->instances != USHRT_MAX && --st->script->instances == 0 ) {
 			if( st->script->local.vars && !db_size(st->script->local.vars) ) {
 				script->free_vars(st->script->local.vars);
 				st->script->local.vars = NULL;
diff --git a/src/map/script.h b/src/map/script.h
index 73ba7303e..cf7f22aa9 100644
--- a/src/map/script.h
+++ b/src/map/script.h
@@ -371,6 +371,7 @@ struct script_code {
 	int script_size;
 	unsigned char *script_buf;
 	struct reg_db local; ///< Local (npc) vars
+	unsigned short instances;
 };
 
 struct script_stack {
@@ -407,7 +408,7 @@ struct script_state {
 	int pos;
 	enum e_script_state state;
 	int rid,oid;
-	struct script_code *script, *scriptroot;
+	struct script_code *script;
 	struct sleep_data {
 		int tick,timer,charid;
 	} sleep;