Fix NPC script softlockv18.3.22

When an NPC called destroy; from an attached script, npc_id, and
associated state, was not properly cleared. This meant that the
server considered the PC to still be in conversation, preventing
many actions including walking, but with an invalid NPC.

This clears state for the specific case of the a PC attached to
the script instance that called destroy. It is still not safe to
call destroy; if other players may be attached to it.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/map/script-fun.cpp b/src/map/script-fun.cpp
index e1866bc..8292bdb 100644
--- a/src/map/script-fun.cpp
+++ b/src/map/script-fun.cpp
@@ -1121,6 +1121,7 @@ void builtin_foreach(ScriptState *st)
             x1, y1,
             block_type);
 }
+
 /*========================================
  * Destructs a temp NPC
  *----------------------------------------
@@ -1129,6 +1130,8 @@ static
 void builtin_destroy(ScriptState *st)
 {
     BlockId id;
+    dumb_ptr<map_session_data> sd;
+
     if (HARG(0))
         id = wrap<BlockId>(conv_num(st, &AARG(0)));
     else
@@ -1138,6 +1141,14 @@ void builtin_destroy(ScriptState *st)
     if(!nd || nd->npc_subtype != NpcSubtype::SCRIPT)
         return;
 
+    /* If we have a player attached, make sure it is cleared. */
+    /* Not safe to call destroy if others may also be paused on this NPC! */
+    if (st->rid) {
+        sd = script_rid2sd(st);
+        nullpo_retv(sd);
+        npc_event_dequeue(sd);
+    }
+
     nd = nd->is_script();
     npc_free(nd);
     st->oid = BlockId();