Fixed crash on first map update

The crash happened when it was trying to move an NPC from its old zone
to its new zone. The old zone was based on the old position, which was
(0,0). That crashed since its zone didn't match its old position, but
its new one.

This fix makes sure to update the old position to be in sync with the
zone, by resetting it after being inserted into the MapComposite.

Reviewed-by: Yohann Ferreira

2 files changed, 16 insertions, 0 deletions

diff --git a/src/game-server/being.cpp b/src/game-server/being.cpp
index d27eb179..07a0a9fc 100644
--- a/src/game-server/being.cpp
+++ b/src/game-server/being.cpp
@@ -292,6 +292,9 @@ void Being::move()
         || !getModifiedAttribute(ATTR_MOVE_SPEED_RAW))
           return;
 
+    // Remember the current position before moving. This is used by
+    // MapComposite::update() to determine whether a being has moved from one
+    // zone to another.
     mOld = getPosition();
 
     if (mMoveTime > WORLD_TICK_MS)
@@ -660,6 +663,15 @@ void Being::update()
         died();
 }
 
+void Being::inserted()
+{
+    Actor::inserted();
+
+    // Reset the old position, since after insertion it is important that it is
+    // in sync with the zone that we're currently present in.
+    mOld = getPosition();
+}
+
 void Being::setTimerSoft(TimerID id, int value)
 {
     Timers::iterator i = mTimers.find(id);
diff --git a/src/game-server/being.h b/src/game-server/being.h
index 35457bcb..b210688a 100644
--- a/src/game-server/being.h
+++ b/src/game-server/being.h
@@ -286,6 +286,10 @@ class Being : public Actor
         void setTarget(Being *target)
         { mTarget = target; }
 
+        /**
+         * Overridden in order to reset the old position upon insertion.
+         */
+        virtual void inserted();
 
     protected:
         static const int TICKS_PER_HP_REGENERATION = 100;