From 16007aade37805e8aecab4069fb7564173352734 Mon Sep 17 00:00:00 2001
From: visualfc <visualfc@gmail.com>
Date: Thu, 5 Dec 2024 16:09:38 +0800
Subject: [PATCH] AssignableConv check underlying basic

---
 builtin_test.go | 19 +++++++++++++++++++
 template.go     | 38 +++++++++++++++++++++-----------------
 2 files changed, 40 insertions(+), 17 deletions(-)

diff --git a/builtin_test.go b/builtin_test.go
index 797dbf92..7a657ff8 100644
--- a/builtin_test.go
+++ b/builtin_test.go
@@ -1341,4 +1341,23 @@ func TestToTag(t *testing.T) {
 	}
 }
 
+func TestAssignableUntyped(t *testing.T) {
+	f64 := types.NewNamed(types.NewTypeName(token.NoPos, nil, "Float64", nil),
+		types.Typ[types.UntypedFloat], nil)
+	i64 := types.NewNamed(types.NewTypeName(token.NoPos, nil, "Int64", nil),
+		types.Typ[types.UntypedInt], nil)
+	if assignableTo(f64, types.Typ[types.UntypedInt], nil) {
+		t.Fatal("error f2i")
+	}
+	if !assignableTo(f64, types.Typ[types.UntypedFloat], nil) {
+		t.Fatal("must f2f")
+	}
+	if !assignableTo(i64, types.Typ[types.UntypedInt], nil) {
+		t.Fatal("must i2i")
+	}
+	if !assignableTo(i64, types.Typ[types.UntypedFloat], nil) {
+		t.Fatal("must i2f")
+	}
+}
+
 // ----------------------------------------------------------------------------
diff --git a/template.go b/template.go
index fa26a8ad..7e24ed07 100644
--- a/template.go
+++ b/template.go
@@ -265,11 +265,26 @@ func AssignableConv(pkg *Package, V, T types.Type, pv *Element) bool {
 		V = getElemTypeIf(V, pv)
 	}
 	if types.AssignableTo(V, T) {
-		if t, ok := T.(*types.Basic); ok { // untyped type
-			vkind := V.(*types.Basic).Kind()
-			tkind := t.Kind()
-			switch {
-			case vkind >= types.UntypedInt && vkind <= types.UntypedComplex:
+		return assignableTo(V, T, pv)
+	}
+	if t, ok := T.(*types.Named); ok {
+		ok = assignable(pkg, V, t, pv)
+		if debugMatch && pv != nil {
+			log.Println("==> AssignableConv", V, T, ok)
+		}
+		return ok
+	}
+	if pkg.implicitCast != nil {
+		return pkg.implicitCast(pkg, V, T, pv)
+	}
+	return false
+}
+
+func assignableTo(V, T types.Type, pv *Element) bool {
+	if t, ok := T.Underlying().(*types.Basic); ok { // untyped type
+		if v, ok := V.Underlying().(*types.Basic); ok {
+			tkind, vkind := t.Kind(), v.Kind()
+			if vkind >= types.UntypedInt && vkind <= types.UntypedComplex {
 				if tkind <= types.Uintptr && pv != nil && outOfRange(tkind, pv.CVal) {
 					if debugMatch {
 						log.Printf("==> AssignableConv %v (%v): value is out of %v range", V, pv.CVal, T)
@@ -290,19 +305,8 @@ func AssignableConv(pkg *Package, V, T types.Type, pv *Element) bool {
 				}
 			}
 		}
-		return true
 	}
-	if t, ok := T.(*types.Named); ok {
-		ok = assignable(pkg, V, t, pv)
-		if debugMatch && pv != nil {
-			log.Println("==> AssignableConv", V, T, ok)
-		}
-		return ok
-	}
-	if pkg.implicitCast != nil {
-		return pkg.implicitCast(pkg, V, T, pv)
-	}
-	return false
+	return true
 }
 
 func outOfRange(tkind types.BasicKind, cval constant.Value) bool {