Make the function environment optional in entity callbacks.

source/Entity/Blip.cpp

@@ -105,6 +105,11 @@ void CBlip::BindEvent(Int32 evid, Object & env, Function & func) const
     {
         event.Release(); // Then release the current callback
     }
+    // Does this function need a custom environment?
+    else if (env.IsNull())
+    {
+        event = func;
+    }
     // Assign the specified environment and function
     else
     {

source/Entity/Checkpoint.cpp

@@ -118,6 +118,11 @@ void CCheckpoint::BindEvent(Int32 evid, Object & env, Function & func) const
     {
         event.Release(); // Then release the current callback
     }
+    // Does this function need a custom environment?
+    else if (env.IsNull())
+    {
+        event = func;
+    }
     // Assign the specified environment and function
     else
     {

source/Entity/Keybind.cpp

@@ -105,6 +105,11 @@ void CKeybind::BindEvent(Int32 evid, Object & env, Function & func) const
     {
         event.Release(); // Then release the current callback
     }
+    // Does this function need a custom environment?
+    else if (env.IsNull())
+    {
+        event = func;
+    }
     // Assign the specified environment and function
     else
     {

source/Entity/Object.cpp

@@ -118,6 +118,11 @@ void CObject::BindEvent(Int32 evid, Object & env, Function & func) const
     {
         event.Release(); // Then release the current callback
     }
+    // Does this function need a custom environment?
+    else if (env.IsNull())
+    {
+        event = func;
+    }
     // Assign the specified environment and function
     else
     {

source/Entity/Pickup.cpp

@@ -110,6 +110,11 @@ void CPickup::BindEvent(Int32 evid, Object & env, Function & func) const
     {
         event.Release(); // Then release the current callback
     }
+    // Does this function need a custom environment?
+    else if (env.IsNull())
+    {
+        event = func;
+    }
     // Assign the specified environment and function
     else
     {

source/Entity/Player.cpp

@@ -127,6 +127,11 @@ void CPlayer::BindEvent(Int32 evid, Object & env, Function & func) const
     {
         event.Release(); // Then release the current callback
     }
+    // Does this function need a custom environment?
+    else if (env.IsNull())
+    {
+        event = func;
+    }
     // Assign the specified environment and function
     else
     {

source/Entity/Vehicle.cpp

@@ -114,6 +114,11 @@ void CVehicle::BindEvent(Int32 evid, Object & env, Function & func) const
     {
         event.Release(); // Then release the current callback
     }
+    // Does this function need a custom environment?
+    else if (env.IsNull())
+    {
+        event = func;
+    }
     // Assign the specified environment and function
     else
     {