TexMgr_Downsample : stb_image_resize routine uses internally-alocated…

… memory, so plug our allocators in

(plus some cosmetic re-arrangements in STB-related config in image.c, for redability)

Quake/gl_texmgr.c

@@ -32,16 +32,23 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #include "SDL.h"
 #endif
 
-#define STB_IMAGE_RESIZE_IMPLEMENTATION
-#define STB_IMAGE_RESIZE_STATIC
 #if defined(__GNUC__)
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-function"
 #elif defined(_MSC_VER)
 #pragma warning(push)
 #pragma warning(disable : 4505)
 #endif
+
+#define STB_IMAGE_RESIZE_IMPLEMENTATION
+#define STB_IMAGE_RESIZE_STATIC
+// STB_IMAGERESIZE config:
+// plug our Mem_Alloc in stb_image_resize:
+// use comma operator to evaluate c, to avoid "unused parameter" warnings
+#define STBIR_MALLOC(sz, c) ((void)(c), Mem_Alloc (sz))
+#define STBIR_FREE(p, c)	((void)(c), Mem_Free (p))
 #include "stb_image_resize.h"
+
 #if defined(__GNUC__)
 #pragma GCC diagnostic pop
 #elif defined(_MSC_VER)

Quake/image.c

@@ -26,6 +26,18 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 static byte *Image_LoadPCX (FILE *f, int *width, int *height);
 static byte *Image_LoadLMP (FILE *f, int *width, int *height);
 
+#ifdef _MSC_VER
+// Disable warning C4505: Unused functions
+#pragma warning(push)
+#pragma warning(disable : 4505)
+#endif
+
+#ifdef __GNUC__
+// Suppress unused function warnings on GCC/clang
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 // STB_IMAGE config:
 #define STB_IMAGE_IMPLEMENTATION
 #define STB_IMAGE_STATIC
@@ -40,19 +52,6 @@ static byte *Image_LoadLMP (FILE *f, int *width, int *height);
 #define STBI_MALLOC(sz)		   Mem_Alloc (sz)
 #define STBI_REALLOC(p, newsz) Mem_Realloc (p, newsz)
 #define STBI_FREE(p)		   Mem_Free (p)
-
-#ifdef _MSC_VER
-// Disable warning C4505: Unused functions
-#pragma warning(push)
-#pragma warning(disable : 4505)
-#endif
-
-#ifdef __GNUC__
-// Suppress unused function warnings on GCC/clang
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
-#endif
-
 #include "stb_image.h"
 
 #ifdef __GNUC__