Decode: convert table key to correct type (#741)

Fixes #740.

internal/imported_tests/unmarshal_imported_test.go

@@ -927,6 +927,29 @@ func TestUnmarshalMapWithTypedKey(t *testing.T) {
 	}
 }
 
+func TestUnmarshalTypeTableHeader(t *testing.T) {
+	testToml := []byte(`
+		[test]
+		a = 1
+		`)
+
+	type header string
+	var result map[header]map[string]int
+	err := toml.Unmarshal(testToml, &result)
+	if err != nil {
+		t.Errorf("Received unexpected error: %s", err)
+		return
+	}
+
+	expected := map[header]map[string]int{
+		"test": map[string]int{"a": 1},
+	}
+
+	if !reflect.DeepEqual(result, expected) {
+		t.Errorf("Bad unmarshal: expected %v, got %v", expected, result)
+	}
+}
+
 func TestUnmarshalNonPointer(t *testing.T) {
 	a := 1
 	err := toml.Unmarshal([]byte{}, a)

unmarshaler.go

@@ -412,9 +412,10 @@ func (d *decoder) handleKeyPart(key ast.Iterator, v reflect.Value, nextFn handle
 		elem = v.Elem()
 		return d.handleKeyPart(key, elem, nextFn, makeFn)
 	case reflect.Map:
+		vt := v.Type()
 
-		// Create the key for the map element. For now assume it's a string.
-		mk := reflect.ValueOf(string(key.Node().Data))
+		// Create the key for the map element. Convert to key type.
+		mk := reflect.ValueOf(string(key.Node().Data)).Convert(vt.Key())
 
 		// If the map does not exist, create it.
 		if v.IsNil() {
@@ -431,7 +432,6 @@ func (d *decoder) handleKeyPart(key ast.Iterator, v reflect.Value, nextFn handle
 			// map[string]interface{} or a []interface{} depending on whether
 			// this is the last part of the array table key.
 
-			vt := v.Type()
 			t := vt.Elem()
 			if t.Kind() == reflect.Interface {
 				mv = makeFn()