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Fix crash when saving games

--- a/CMakeLists.txt

+++ b/CMakeLists.txt

@@ -41,6 +41,11 @@

 	add_definitions(-DUNIX)

 	add_compile_options("-Wall")

+	# Duke 3D source code is not at all thought out for strict aliasing.

+	# Really not! It's full of dangerous pointer casting.

+	# Without this option, game will crash at random places when compiled with -O2 or-O3.

+	add_compile_options("-fno-strict-aliasing") 

+

 endif ()

 if(CMAKE_SIZEOF_VOID_P EQUAL 8)

--- a/Engine/src/fixedPoint_math.c

+++ b/Engine/src/fixedPoint_math.c

@@ -1,13 +1,33 @@

 // converted from asm to c by Jonof

 #include <stdio.h>

+#include <string.h>

 #include "platform.h"

 #include "fixedPoint_math.h"

 void clearbuf(void *d, int32_t c, int32_t a)

 {

-	int32_t *p = (int32_t*)d;

-	while ((c--) > 0) *(p++) = a;

+    // tanguyf: this completely violates strict-aliasing.

+	//int32_t *p = (int32_t*)d;

+	//while ((c--) > 0) *(p++) = a;

+

+	union

+    {

+	    struct { uint8_t a,b,c,d; };

+	    int32_t value;

+    } src;

+

+	src.value = a;

+

+	uint8_t* dst = (uint8_t*) d;

+

+	for (int32_t i = 0; i < c; ++i)

+    {

+	    dst[i*4 + 0] = src.a;

+        dst[i*4 + 1] = src.b;

+        dst[i*4 + 2] = src.c;

+        dst[i*4 + 3] = src.d;

+    }

 }

 void clearbufbyte(void *D, int32_t c, int32_t a)

@@ -24,8 +44,10 @@

 void copybuf(void *s, void *d, int32_t c)

 {

-	int32_t *p = (int32_t*)s, *q = (int32_t*)d;

-	while ((c--) > 0) *(q++) = *(p++);

+    // tanguyf: this completely violates strict-aliasing.

+	//int32_t *p = (int32_t*)s, *q = (int32_t*)d;

+	//while ((c--) > 0) *(q++) = *(p++);

+	memcpy(d, s, c * sizeof(int32_t));

 }

 void copybufbyte(void *S, void *D, int32_t c)

--- a/README.md

+++ b/README.md

@@ -23,7 +23,6 @@

 ### Known Issues

-* Linux: savegames do not work or crash the engine.

 * Engine: Leaning left/right falls back to low-res rendering.

 * Engine: Minimap has rendering glitches when fully-textured (i.e. sprites).

 * Engine: Pixel imprecision when rendering health/ammo numbers in the status bar, leaving ghost pixels.