Attempt replacement of memory allocation functions with primitive working alternatives

amiga/Makefile.target

@@ -61,6 +61,7 @@ else
   ifeq ($(SUBTARGET),os3)
     LDFLAGS += -lpbl -liconv
   else
+    CFLAGS += -DAMIGA_NETSURF_REPLACE_ALLOC
     LDFLAGS += -lauto -lpbl -liconv
   endif
 endif
@@ -80,7 +81,7 @@ S_AMIGA := gui.c tree.c history.c hotlist.c schedule.c file.c	\
 	sslcert.c gui_options.c print.c	theme.c	drag.c icon.c system_colour.c \
 	datatypes.c dt_picture.c dt_anim.c dt_sound.c plugin_hack.c	\
 	stringview/stringview.c stringview/urlhistory.c				\
-	agclass/amigaguide_class.c
+	agclass/amigaguide_class.c alloc.c
 S_AMIGA := $(addprefix amiga/,$(S_AMIGA))
 
 # This is the final source build list

amiga/alloc.c

@@ -0,0 +1,36 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <proto/exec.h>
+
+#ifdef AMIGA_NETSURF_REPLACE_ALLOC
+#define nsa_malloc malloc
+#define nsa_calloc calloc
+#define nsa_realloc realloc
+#define nsa_free free
+#endif
+
+void nsa_free(void *p) {
+	if(p == NULL) return;
+	UBYTE *mem = p - 4;
+	FreeVec(mem);
+}
+void *nsa_malloc(size_t s) {
+	UBYTE *mem = AllocVec(s + 4, MEMF_PRIVATE);
+	*mem = s;
+    return mem + 4;
+}
+void *nsa_calloc(size_t nelem, size_t nsize) {
+	UBYTE *mem = AllocVec((nelem * nsize) + 4, MEMF_PRIVATE | MEMF_CLEAR);
+	*mem = (nelem * nsize);
+    return mem + 4;
+}
+void *nsa_realloc(void *p, size_t s) {
+	void *newptr;
+	ULONG old_size = *((UBYTE *)p - 4);
+    newptr = nsa_malloc(s);
+    memcpy(newptr, p, old_size);
+    nsa_free(p);
+    return newptr;
+}