From 0362a0dff481085526db2a55a06891fe3afe2632 Mon Sep 17 00:00:00 2001
From: GenericHeroGuy <genericheroguy@noreply.codeberg.org>
Date: Thu, 18 Sep 2025 16:30:37 +0200
Subject: [PATCH] Add debugmappatch, for hot-reloading map patches

---
 src/d_netcmd.c |  3 +++
 src/d_netcmd.h |  2 ++
 src/p_setup.c  | 32 ++++++++++++++++++++++----------
 3 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/src/d_netcmd.c b/src/d_netcmd.c
index 4d90bc678..99618fa4a 100644
--- a/src/d_netcmd.c
+++ b/src/d_netcmd.c
@@ -706,6 +706,8 @@ consvar_t cv_schedule = CVAR_INIT ("schedule", "On", CV_NETVAR|CV_CALL, CV_OnOff
 
 consvar_t cv_automate = CVAR_INIT ("automate", "On", CV_NETVAR, CV_OnOff, NULL);
 
+consvar_t cv_debugmappatch = CVAR_INIT ("debugmappatch", "", 0, NULL, NULL);
+
 char timedemo_name[256];
 boolean timedemo_csv;
 char timedemo_csv_id[256];
@@ -1312,6 +1314,7 @@ void D_RegisterClientCommands(void)
 	CV_RegisterVar(&cv_connectawaittime);
 	CV_RegisterVar(&cv_serverinfoscreen);
 
+	CV_RegisterVar(&cv_debugmappatch);
 }
 
 /**
diff --git a/src/d_netcmd.h b/src/d_netcmd.h
index 385f7a3eb..a0d2ea124 100644
--- a/src/d_netcmd.h
+++ b/src/d_netcmd.h
@@ -244,6 +244,8 @@ extern consvar_t cv_director;
 
 extern consvar_t cv_schedule;
 
+extern consvar_t cv_debugmappatch;
+
 extern char timedemo_name[256];
 extern boolean timedemo_csv;
 extern char timedemo_csv_id[256];
diff --git a/src/p_setup.c b/src/p_setup.c
index d7aec5693..427a7ab4c 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -3746,21 +3746,17 @@ static boolean P_LoadMapData(const virtres_t *virt)
 	return true;
 }
 
-static boolean P_LoadMapPatchData(const lumpnum_t lumpnum)
+static boolean P_LoadMapPatchData(const char *patchdata, size_t patchlen)
 {
 	TracyCZone(__zone, true);
 
 	size_t realnummapthings = nummapthings;
 
 	// Count map data.
-	size_t patchlen = W_LumpLength(lumpnum);
-	char *patchdata = malloc(patchlen);
-	W_ReadLump(lumpnum, patchdata);
 	M_TokenizerOpen(patchdata, patchlen);
 	if (!TextmapCount(patchlen, true))
 	{
 		M_TokenizerClose();
-		free(patchdata);
 		TracyCZoneEnd(__zone);
 		return false;
 	}
@@ -3771,7 +3767,6 @@ static boolean P_LoadMapPatchData(const lumpnum_t lumpnum)
 	// Load map data.
 	P_LoadTextmap(true);
 	M_TokenizerClose();
-	free(patchdata);
 
 	// concatenate the two mapthing arrays
 	realmapthings = Z_Realloc(realmapthings, (nummapthings + realnummapthings) * sizeof (*mapthings), PU_LEVEL, NULL);
@@ -7945,10 +7940,27 @@ static boolean P_LoadMapFromFile(void)
 	P_MakeMapHash(curmapvirt, &maphash);
 
 	// load map patch?
-	lumpnum_t patchlump = W_CheckNumForNameInFolder(G_BuildMapName(gamemap), "MapPatch/");
-	if (patchlump != LUMPERROR)
-		if (!P_LoadMapPatchData(patchlump))
-			CONS_Alert(CONS_ERROR, "Failed to load map patch for %s\n", G_BuildMapName(gamemap));
+	char *patchdata = NULL;
+	size_t patchlen;
+	if (cv_debugmappatch.string[0])
+	{
+		patchlen = FIL_ReadFile(cv_debugmappatch.string, (UINT8 **)(&patchdata));
+	}
+	else
+	{
+		lumpnum_t patchlump = W_CheckNumForNameInFolder(G_BuildMapName(gamemap), "MapPatch/");
+		if (patchlump != LUMPERROR)
+		{
+			patchlen = W_LumpLength(patchlump);
+			patchdata = Z_Malloc(patchlen, PU_STATIC, NULL);
+			W_ReadLump(patchlump, patchdata);
+		}
+	}
+
+	if (patchdata != NULL && !P_LoadMapPatchData(patchdata, patchlen))
+		CONS_Alert(CONS_ERROR, "Failed to load map patch for %s\n", G_BuildMapName(gamemap));
+
+	Z_Free(patchdata);
 
 	// Copy relevant map data for NetArchive purposes.
 	P_DeepCopySectors(&spawnsectors, &sectors, numsectors);