Restore Q_* alloc features

source/zone.c

@@ -382,6 +382,68 @@ bytecopy:
 	return (dst);
 }
 
+/*
+===================
+Q_malloc
+Use it instead of malloc so that if memory allocation fails,
+the program exits with a message saying there's not enough memory
+instead of crashing after trying to use a NULL pointer
+===================
+*/
+void *Q_malloc (size_t size)
+{
+	void	*p;
+
+	if (!(p = malloc(size)))
+		Sys_Error ("Not enough memory free; check disk space");
+
+	return p;
+}
+
+/*
+===================
+Q_calloc
+===================
+*/
+void *Q_calloc (size_t n, size_t size)
+{
+	void	*p;
+
+	if (!(p = calloc(n, size)))
+		Sys_Error ("Not enough memory free; check disk space");
+
+	return p;
+}
+
+/*
+===================
+Q_realloc
+===================
+*/
+void *Q_realloc (void *ptr, size_t size)
+{
+	void	*p;
+
+	if (!(p = realloc(ptr, size)))
+		Sys_Error ("Not enough memory free; check disk space");
+
+	return p;
+}
+
+/*
+===================
+Q_strdup
+===================
+*/
+void *Q_strdup (const char *str)
+{
+	char	*p;
+
+	if (!(p = strdup(str)))
+		Sys_Error ("Not enough memory free; check disk space");
+
+	return p;
+}
 
 /*
 ==============================================================================