Turn 'Filename' into a dynamically allocated type with no arbitrary

length limit, just as I did to FontSpec yesterday.

[originally from svn r9316]

windows/winmisc.c

@@ -14,27 +14,58 @@ char *platform_get_x_display(void) {
     return dupstr(getenv("DISPLAY"));
 }
 
-Filename filename_from_str(const char *str)
+Filename *filename_from_str(const char *str)
 {
-    Filename ret;
-    strncpy(ret.path, str, sizeof(ret.path));
-    ret.path[sizeof(ret.path)-1] = '\0';
+    Filename *ret = snew(Filename);
+    ret->path = dupstr(str);
     return ret;
 }
 
+Filename *filename_copy(const Filename *fn)
+{
+    return filename_from_str(fn->path);
+}
+
 const char *filename_to_str(const Filename *fn)
 {
     return fn->path;
 }
 
-int filename_equal(Filename f1, Filename f2)
+int filename_equal(const Filename *f1, const Filename *f2)
 {
-    return !strcmp(f1.path, f2.path);
+    return !strcmp(f1->path, f2->path);
 }
 
-int filename_is_null(Filename fn)
+int filename_is_null(const Filename *fn)
 {
-    return !*fn.path;
+    return !*fn->path;
+}
+
+void filename_free(Filename *fn)
+{
+    sfree(fn->path);
+    sfree(fn);
+}
+
+int filename_serialise(const Filename *f, void *vdata)
+{
+    char *data = (char *)vdata;
+    int len = strlen(f->path) + 1;     /* include trailing NUL */
+    if (data) {
+        strcpy(data, f->path);
+    }
+    return len;
+}
+Filename *filename_deserialise(void *vdata, int maxsize, int *used)
+{
+    char *data = (char *)vdata;
+    char *end;
+    end = memchr(data, '\0', maxsize);
+    if (!end)
+        return NULL;
+    end++;
+    *used = end - data;
+    return filename_from_str(data);
 }
 
 char *get_username(void)