Suppose we want to know C.IsAssignableFrom (T1):
```
class C { }
class G<T1, T2> where T1 : T2, T2 : C { }
```
Previously, we would get `False`, because we only checked the constraints of T1
if C was an interface or another gparam. Now Instead we always consider the
constraints in `A.IsAssignableFrom (B)` whenever `B` is a gparam.
Fixes https://bugzilla.xamarin.com/show_bug.cgi?id=58809
return mono_gparam_is_assignable_from (klass, oklass);
}
return mono_gparam_is_assignable_from (klass, oklass);
}
- if (MONO_CLASS_IS_INTERFACE (klass)) {
- if ((oklass->byval_arg.type == MONO_TYPE_VAR) || (oklass->byval_arg.type == MONO_TYPE_MVAR)) {
- MonoGenericParam *gparam = oklass->byval_arg.data.generic_param;
- MonoClass **constraints = mono_generic_container_get_param_info (gparam->owner, gparam->num)->constraints;
- int i;
+ /* This can happen if oklass is a tyvar that has a constraint which is another tyvar which in turn
+ * has a constraint which is a class type:
+ *
+ * class Foo { }
+ * class G<T1, T2> where T1 : T2 where T2 : Foo { }
+ *
+ * In this case, Foo is assignable from T1.
+ */
+ if ((oklass->byval_arg.type == MONO_TYPE_VAR) || (oklass->byval_arg.type == MONO_TYPE_MVAR)) {
+ MonoGenericParam *gparam = oklass->byval_arg.data.generic_param;
+ MonoClass **constraints = mono_generic_container_get_param_info (gparam->owner, gparam->num)->constraints;
+ int i;
- if (constraints) {
- for (i = 0; constraints [i]; ++i) {
- if (mono_class_is_assignable_from (klass, constraints [i]))
- return TRUE;
- }
+ if (constraints) {
+ for (i = 0; constraints [i]; ++i) {
+ if (mono_class_is_assignable_from (klass, constraints [i]))
+ return TRUE;
+ return mono_class_has_parent (oklass, klass);
+ }
+
+ if (MONO_CLASS_IS_INTERFACE (klass)) {
+
/* interface_offsets might not be set for dynamic classes */
if (mono_class_get_ref_info_handle (oklass) && !oklass->interface_bitmap) {
/*
/* interface_offsets might not be set for dynamic classes */
if (mono_class_get_ref_info_handle (oklass) && !oklass->interface_bitmap) {
/*