From dd9bdab8dcf79bdf7bedd204530bb70ce73f1ce9 Mon Sep 17 00:00:00 2001
From: Spoike <acceptthis@users.sourceforge.net>
Date: Tue, 8 Mar 2022 05:30:30 +0000
Subject: [PATCH] Add ZG_Free function for zonegroup memory.

git-svn-id: https://svn.code.sf.net/p/fteqw/code/trunk@6208 fc73d0e0-1445-4013-8a0c-d673dee63da5
---
 engine/common/zone.c | 36 +++++++++++++++++++++++++++++++++++-
 engine/common/zone.h |  3 ++-
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/engine/common/zone.c b/engine/common/zone.c
index cf84b6d1..af974267 100644
--- a/engine/common/zone.c
+++ b/engine/common/zone.c
@@ -540,7 +540,16 @@ typedef struct zonegroupblock_s
 {
 	union
 	{
-		struct zonegroupblock_s *next;
+		struct
+		{
+			struct zonegroupblock_s *next;
+			struct zonegroupblock_s *prev;
+#ifdef _DEBUG
+			#define ZONEGROUP_SENTINAL 0x709ef00d
+			unsigned int sentinal;
+			unsigned int size;
+#endif
+		};
 		vec4_t align16;
 	};
 } zonegroupblock_t;
@@ -561,11 +570,36 @@ void *QDECL ZG_Malloc(zonegroup_t *ctx, size_t size)
 	newm = Z_Malloc(size);
 #endif
 
+	newm->prev = NULL;
+	if (ctx->first)
+		((zonegroupblock_t*)ctx->first)->prev = newm;
 	newm->next = ctx->first;
 	ctx->first = newm;
 	ctx->totalbytes += size;
+
+#ifdef _DEBUG
+	newm->sentinal = ZONEGROUP_SENTINAL;
+	newm->size = size;
+#endif
 	return(void*)(newm+1);
 }
+void ZG_Free(zonegroup_t *ctx, void *ptr)
+{
+	zonegroupblock_t *mem = (zonegroupblock_t*)ptr-1;
+	if (mem->prev)
+		mem->prev->next = mem->next;
+	else
+		ctx->first = mem->next;
+	if (mem->next)
+		mem->next->prev = mem->prev;
+
+#ifdef _DEBUG
+	if (mem->sentinal != ZONEGROUP_SENTINAL)
+		Sys_Error("Corrupt memory");
+	ctx->totalbytes -= mem->size;
+#endif
+	BZ_Free(mem);
+}
 void ZG_FreeGroup(zonegroup_t *ctx)
 {
 	zonegroupblock_t *old;
diff --git a/engine/common/zone.h b/engine/common/zone.h
index a3de3148..25decbd1 100644
--- a/engine/common/zone.h
+++ b/engine/common/zone.h
@@ -133,7 +133,8 @@ typedef struct zonegroup_s
 } zonegroup_t;
 void *QDECL ZG_Malloc(zonegroup_t *ctx, size_t size);
 void *ZG_MallocNamed(zonegroup_t *ctx, size_t size, char *file, int line);
-void ZG_FreeGroup(zonegroup_t *ctx);
+void QDECL ZG_Free(zonegroup_t *ctx, void *ptr);
+void QDECL ZG_FreeGroup(zonegroup_t *ctx);
 
 #ifdef USE_MSVCRT_DEBUG
 #define BZ_Malloc(size) BZ_MallocNamed(size, __FILE__, __LINE__)