From e3ded1671c48906152c7ee29769b86880b49b61c Mon Sep 17 00:00:00 2001
From: Monster Iestyn <iestynjealous@ntlworld.com>
Date: Sat, 21 Jan 2017 23:49:18 +0000
Subject: [PATCH] Added MobjMoveBlocked Lua hook

Also slightly edited P_XYMovement to properly check the mobj still exists before checking its eflags for MFE_SPRUNG, while I was at it
---
 src/lua_hook.h    |  2 ++
 src/lua_hooklib.c |  3 +++
 src/p_mobj.c      | 26 +++++++++++++++++++-------
 3 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/src/lua_hook.h b/src/lua_hook.h
index 7192a2979..88867db2b 100644
--- a/src/lua_hook.h
+++ b/src/lua_hook.h
@@ -45,6 +45,7 @@ enum hook {
 	hook_PlayerSpawn,
 	hook_ShieldSpawn,
 	hook_ShieldSpecial,
+	hook_MobjMoveBlocked,
 
 	hook_MAX // last hook
 };
@@ -81,5 +82,6 @@ boolean LUAh_HurtMsg(player_t *player, mobj_t *inflictor, mobj_t *source, UINT8
 #define LUAh_PlayerSpawn(player) LUAh_PlayerHook(player, hook_PlayerSpawn) // Hook for G_SpawnPlayer
 #define LUAh_ShieldSpawn(player) LUAh_PlayerHook(player, hook_ShieldSpawn) // Hook for P_SpawnShieldOrb
 #define LUAh_ShieldSpecial(player) LUAh_PlayerHook(player, hook_ShieldSpecial) // Hook for shield abilities
+#define LUAh_MobjMoveBlocked(mo) LUAh_MobjHook(mo, hook_MobjMoveBlocked) // Hook for P_XYMovement (when movement is blocked)
 
 #endif
diff --git a/src/lua_hooklib.c b/src/lua_hooklib.c
index f7ea25224..dadc1861a 100644
--- a/src/lua_hooklib.c
+++ b/src/lua_hooklib.c
@@ -56,6 +56,7 @@ const char *const hookNames[hook_MAX+1] = {
 	"PlayerSpawn",
 	"ShieldSpawn",
 	"ShieldSpecial",
+	"MobjMoveBlocked",
 	NULL
 };
 
@@ -126,6 +127,7 @@ static int lib_addHook(lua_State *L)
 	case hook_BossDeath:
 	case hook_MobjRemoved:
 	case hook_HurtMsg:
+	case hook_MobjMoveBlocked:
 		hook.s.mt = MT_NULL;
 		if (lua_isnumber(L, 2))
 			hook.s.mt = lua_tonumber(L, 2);
@@ -184,6 +186,7 @@ static int lib_addHook(lua_State *L)
 	case hook_MobjDeath:
 	case hook_BossDeath:
 	case hook_MobjRemoved:
+	case hook_MobjMoveBlocked:
 		lastp = &mobjhooks[hook.s.mt];
 		break;
 	case hook_JumpSpecial:
diff --git a/src/p_mobj.c b/src/p_mobj.c
index f1dfa94f5..f71dffeae 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -2122,17 +2122,31 @@ void P_XYMovement(mobj_t *mo)
 	if (CheckForBustableBlocks && mo->flags & MF_PUSHABLE)
 		P_PushableCheckBustables(mo);
 
-	if (!P_TryMove(mo, mo->x + xmove, mo->y + ymove, true) && !(mo->eflags & MFE_SPRUNG))
-	{
-		// blocked move
-		moved = false;
+	moved = P_TryMove(mo, mo->x + xmove, mo->y + ymove, true); // Move!
 
+	if (P_MobjWasRemoved(mo)) // mobj was removed during P_TryMove? don't continue
+		return;
+	if (mo->eflags & MFE_SPRUNG) // touching a spring counts as moved
+		moved = true;
+
+	if (!moved) // blocked move
+	{
 		if (player) {
 			if (player->bot)
 				B_MoveBlocked(player);
 		}
 
-		if (mo->flags & MF_BOUNCE)
+#ifdef HAVE_BLUA
+		if (LUAh_MobjMoveBlocked(mo))
+		{
+			if (P_MobjWasRemoved(mo))
+				return;
+		}
+		else
+#endif
+		if (P_MobjWasRemoved(mo))
+			return;
+		else if (mo->flags & MF_BOUNCE)
 		{
 			P_BounceMove(mo);
 			xmove = ymove = 0;
@@ -2232,8 +2246,6 @@ void P_XYMovement(mobj_t *mo)
 		else
 			mo->momx = mo->momy = 0;
 	}
-	else
-		moved = true;
 
 	if (P_MobjWasRemoved(mo)) // MF_SPECIAL touched a player! O_o;;
 		return;