From c4786a62e6906022db264312ff5569efde0e564f Mon Sep 17 00:00:00 2001
From: Luke Benstead <kazade@gmail.com>
Date: Sat, 7 Dec 2024 19:35:40 +0000
Subject: [PATCH] Fix bug in allocations (thanks @skmp)

---
 GL/alloc/alloc.c               | 17 +++++++++++++----
 samples/nehe08/main.c          |  4 ++--
 samples/nehe20/main.c          |  5 +++--
 samples/primitive_modes/main.c |  1 +
 4 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/GL/alloc/alloc.c b/GL/alloc/alloc.c
index 0058baf..3dfce8e 100644
--- a/GL/alloc/alloc.c
+++ b/GL/alloc/alloc.c
@@ -296,7 +296,7 @@ static inline void block_and_offset_from_subblock(size_t sb, size_t* b, uint8_t*
     *off = (sb % 8);
 }
 
-void* alloc_malloc(void* pool, size_t size) {
+static void* alloc_malloc_internal(void* pool, size_t size, bool for_defrag) {
     DBG_MSG("Allocating: %d\n", size);
 
     size_t start_subblock, required_subblocks;
@@ -339,6 +339,11 @@ void* alloc_malloc(void* pool, size_t size) {
             pool_header.block_usage[block++] |= mask;
         }
 
+        // defrag allocations don't create new entries, they reuse old ones
+        if(for_defrag) {
+            return ret;
+        }
+
         /* Insert allocations in the list by size descending so that when we
          * defrag we can move the larger blocks before the smaller ones without
          * much effort */
@@ -380,6 +385,10 @@ void* alloc_malloc(void* pool, size_t size) {
     return ret;
 }
 
+void* alloc_malloc(void* pool, size_t size) {
+    return alloc_malloc_internal(pool, size, false);
+}
+
 static void alloc_release_blocks(struct AllocEntry* it) {
     size_t used_subblocks = size_to_subblock_count(it->size);
     size_t subblock = subblock_from_pointer(it->pointer);
@@ -437,14 +446,14 @@ void alloc_free(void* pool, void* p) {
 
             DBG_MSG("Freed: size: %d, us: %d, sb: %d, off: %d\n", it->size, used_subblocks, block, offset);
             free(it);
-            break;
+            return;
         }
 
         last = it;
         it = it->next;
     }
 
-    DBG_MSG("Free done\n");
+    assert("Freed pointer not found, heap corruption?" && 0);
 }
 
 void alloc_run_defrag(void* pool, defrag_address_move callback, int max_iterations, void* user_data) {
@@ -461,7 +470,7 @@ void alloc_run_defrag(void* pool, defrag_address_move callback, int max_iteratio
         while(it) {
             void* potential_dest = alloc_next_available(pool, it->size);
             if(potential_dest && potential_dest < it->pointer) {
-                potential_dest = alloc_malloc(pool, it->size);
+                potential_dest = alloc_malloc_internal(pool, it->size, true);
                 memcpy(potential_dest, it->pointer, it->size);
 
                 /* Mark this block as now free, but don't fiddle with the
diff --git a/samples/nehe08/main.c b/samples/nehe08/main.c
index 8d6814d..4048b59 100644
--- a/samples/nehe08/main.c
+++ b/samples/nehe08/main.c
@@ -11,10 +11,10 @@
 #ifdef __DREAMCAST__
 #include <kos.h>
 #endif
-
 #include <GL/gl.h>
-#include <GL/glu.h>
 #include <GL/glkos.h>
+#include <GL/glu.h>
+#include <stdio.h>
 
 /* Simple OpenGL example to demonstrate blending and lighting.
 
diff --git a/samples/nehe20/main.c b/samples/nehe20/main.c
index 54c7825..bce9182 100644
--- a/samples/nehe20/main.c
+++ b/samples/nehe20/main.c
@@ -63,8 +63,9 @@ KOS_INIT_ROMDISK(romdisk);
 #include <GL/glu.h>	// Header File For The GLu32 Library
 #include <GL/glkos.h>
 #else
-#include <GL/gl.h>	// Header File For The OpenGL32 Library
-#include <GL/glu.h>	// Header File For The GLu32 Library
+#include <GL/gl.h> // Header File For The OpenGL32 Library
+#include <GL/glkos.h>
+#include <GL/glu.h> // Header File For The GLu32 Library
 #endif
 
 #define BOOL    int
diff --git a/samples/primitive_modes/main.c b/samples/primitive_modes/main.c
index 09e9ab3..5f7acab 100644
--- a/samples/primitive_modes/main.c
+++ b/samples/primitive_modes/main.c
@@ -1,4 +1,5 @@
 #include <GL/gl.h>
+#include <GL/glkos.h>
 #include <math.h>
 #include <stdlib.h>