From ad8654ed064b94333eec3f1d24f0e339a90d734b Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Sun, 7 Mar 2021 09:39:16 +0100
Subject: [PATCH] - fixed maphack loader.

The duplicate 'currentSprite' variable prevented it from doing anything.
Also cleaned up the interface a bit to avoid using a global variable for parameter passing.

Fixes #279
---
 source/build/include/build.h  | 4 +---
 source/core/maphack.cpp       | 6 ++----
 source/core/maploader.cpp     | 6 +++++-
 source/games/blood/src/db.cpp | 5 +++--
 4 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/source/build/include/build.h b/source/build/include/build.h
index 595404cd6..0e8c43597 100644
--- a/source/build/include/build.h
+++ b/source/build/include/build.h
@@ -173,8 +173,6 @@ struct usermaphack_t
     uint8_t md4[16]{};
 };
 
-extern usermaphack_t g_loadedMapHack;
-
 EXTERN spriteext_t *spriteext;
 EXTERN spritesmooth_t *spritesmooth;
 
@@ -425,7 +423,7 @@ void   initspritelists(void);
 
 void engineLoadBoard(const char *filename, int flags, vec3_t *dapos, int16_t *daang, int16_t *dacursectnum);
 void loadMapBackup(const char* filename);
-void G_LoadMapHack(const char* filename);
+void G_LoadMapHack(const char* filename, const unsigned char*);
 
 int32_t   qloadkvx(int32_t voxindex, const char *filename);
 void vox_undefine(int32_t const);
diff --git a/source/core/maphack.cpp b/source/core/maphack.cpp
index a9d126f54..3a62a0821 100644
--- a/source/core/maphack.cpp
+++ b/source/core/maphack.cpp
@@ -36,7 +36,6 @@
 #include "sc_man.h"
 #include "printf.h"
 
-usermaphack_t g_loadedMapHack;  // used only for the MD4 part
 static TArray<usermaphack_t> usermaphacks;
 
 void AddUserMapHack(usermaphack_t& mhk)
@@ -59,7 +58,6 @@ static int32_t LoadMapHack(const char *filename)
     while (sc.GetString())
     {
         FString token = sc.String;
-        int currentsprite = -1;
         auto validateSprite = [&]()
         {
             if (currentsprite < 0)
@@ -201,7 +199,7 @@ static int32_t LoadMapHack(const char *filename)
 	return 0;
 }
 
-void G_LoadMapHack(const char* filename)
+void G_LoadMapHack(const char* filename, const unsigned char* md4)
 {
     FString hack = StripExtension(filename) + ".mhk";
 
@@ -209,7 +207,7 @@ void G_LoadMapHack(const char* filename)
     {
         for (auto& mhk : usermaphacks)
         {
-            if (!memcmp(g_loadedMapHack.md4, mhk.md4, 16))
+            if (!memcmp(md4, mhk.md4, 16))
             {
                 LoadMapHack(mhk.mhkfile);
             }
diff --git a/source/core/maploader.cpp b/source/core/maploader.cpp
index 4d455ca21..fb34935d1 100644
--- a/source/core/maploader.cpp
+++ b/source/core/maploader.cpp
@@ -439,7 +439,11 @@ void engineLoadBoard(const char* filename, int flags, vec3_t* pos, int16_t* ang,
 	//Must be last.
 	updatesector(pos->x, pos->y, cursectnum);
 	guniqhudid = 0;
-	G_LoadMapHack(filename);
+	fr.Seek(0, FileReader::SeekSet);
+	auto buffer = fr.Read();
+	unsigned char md4[16];
+	md4once(buffer.Data(), buffer.Size(), md4);
+	G_LoadMapHack(filename, md4);
 
 	memcpy(wallbackup, wall, sizeof(wallbackup));
 	memcpy(sectorbackup, sector, sizeof(sectorbackup));
diff --git a/source/games/blood/src/db.cpp b/source/games/blood/src/db.cpp
index e1be1916d..07d372ab7 100644
--- a/source/games/blood/src/db.cpp
+++ b/source/games/blood/src/db.cpp
@@ -979,8 +979,9 @@ void dbLoadMap(const char *pPath, int *pX, int *pY, int *pZ, short *pAngle, shor
 
     fr.Seek(0, FileReader::SeekSet);
     auto buffer = fr.Read();
-    md4once(buffer.Data(), buffer.Size(), g_loadedMapHack.md4);
-    G_LoadMapHack(mapname);
+    unsigned char md4[16];
+    md4once(buffer.Data(), buffer.Size(), md4);
+    G_LoadMapHack(mapname, md4);
 
     if (CalcCRC32(buffer.Data(), buffer.Size() -4) != nCRC)
     {