Fix type aliasing comparison; Fix gb_utf8_decode

1 files changed, 16 insertions, 0 deletions

diff --git a/src/types.cpp b/src/types.cpp
index a28bbf608..a57058dbf 100644
--- a/src/types.cpp
+++ b/src/types.cpp
@@ -1157,6 +1157,19 @@ bool is_type_comparable(Type *t) {
 	return false;
 }
 
+Type *strip_type_aliasing(Type *x) {
+	if (x == nullptr) {
+		return x;
+	}
+	if (x->kind == Type_Named) {
+		Entity *e = x->Named.type_name;
+		if (e != nullptr && e->kind == Entity_TypeName && e->TypeName.is_type_alias) {
+			return x->Named.base;
+		}
+	}
+	return x;
+}
+
 bool are_types_identical(Type *x, Type *y) {
 	if (x == y) {
 		return true;
@@ -1167,6 +1180,9 @@ bool are_types_identical(Type *x, Type *y) {
 		return false;
 	}
 
+	x = strip_type_aliasing(x);
+	y = strip_type_aliasing(y);
+
 	switch (x->kind) {
 	case Type_Generic:
 		if (y->kind == Type_Generic) {