fix bug where package name suffix increased with every use

internal/tests/nameclash/input.go

@@ -24,6 +24,7 @@ type dec struct{}
 
 type Y struct {
 	Foo    json.Foo   `optional:"true"`
+	Foo2   json.Foo   `optional:"true"`
 	Bar    errors.Foo `optional:"true"`
 	Gazonk YJSON      `optional:"true"`
 	Over   int        `optional:"true"`

internal/tests/nameclash/output.go

@@ -12,12 +12,14 @@ import (
 func (y *Y) MarshalJSON() ([]byte, error) {
 	type YJSON0 struct {
 		Foo    *json0.Foo   `optional:"true"`
+		Foo2   *json0.Foo   `optional:"true"`
 		Bar    *errors0.Foo `optional:"true"`
 		Gazonk *YJSON       `optional:"true"`
 		Over   *enc         `optional:"true"`
 	}
 	var enc0 YJSON0
 	enc0.Foo = &y.Foo
+	enc0.Foo2 = &y.Foo2
 	enc0.Bar = &y.Bar
 	enc0.Gazonk = &y.Gazonk
 	enc0.Over = (*enc)(&y.Over)
@@ -27,6 +29,7 @@ func (y *Y) MarshalJSON() ([]byte, error) {
 func (y *Y) UnmarshalJSON(input []byte) error {
 	type YJSON0 struct {
 		Foo    *json0.Foo   `optional:"true"`
+		Foo2   *json0.Foo   `optional:"true"`
 		Bar    *errors0.Foo `optional:"true"`
 		Gazonk *YJSON       `optional:"true"`
 		Over   *enc         `optional:"true"`
@@ -39,6 +42,9 @@ func (y *Y) UnmarshalJSON(input []byte) error {
 	if dec.Foo != nil {
 		x.Foo = *dec.Foo
 	}
+	if dec.Foo2 != nil {
+		x.Foo2 = *dec.Foo2
+	}
 	if dec.Bar != nil {
 		x.Bar = *dec.Bar
 	}
@@ -55,12 +61,14 @@ func (y *Y) UnmarshalJSON(input []byte) error {
 func (y *Y) MarshalYAML() (interface{}, error) {
 	type YYAML struct {
 		Foo    *json0.Foo   `optional:"true"`
+		Foo2   *json0.Foo   `optional:"true"`
 		Bar    *errors0.Foo `optional:"true"`
 		Gazonk *YJSON       `optional:"true"`
 		Over   *enc         `optional:"true"`
 	}
 	var enc0 YYAML
 	enc0.Foo = &y.Foo
+	enc0.Foo2 = &y.Foo2
 	enc0.Bar = &y.Bar
 	enc0.Gazonk = &y.Gazonk
 	enc0.Over = (*enc)(&y.Over)
@@ -70,6 +78,7 @@ func (y *Y) MarshalYAML() (interface{}, error) {
 func (y *Y) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	type YYAML struct {
 		Foo    *json0.Foo   `optional:"true"`
+		Foo2   *json0.Foo   `optional:"true"`
 		Bar    *errors0.Foo `optional:"true"`
 		Gazonk *YJSON       `optional:"true"`
 		Over   *enc         `optional:"true"`
@@ -82,6 +91,9 @@ func (y *Y) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	if dec.Foo != nil {
 		x.Foo = *dec.Foo
 	}
+	if dec.Foo2 != nil {
+		x.Foo2 = *dec.Foo2
+	}
 	if dec.Bar != nil {
 		x.Bar = *dec.Bar
 	}

typeutil.go

@@ -166,7 +166,7 @@ func (s *fileScope) addReferences(typ types.Type) {
 // rebuild the import name cache.
 func (s *fileScope) insertImport(pkg *types.Package) {
 	i := sort.Search(len(s.imports), func(i int) bool {
-		return s.imports[i].Path() > pkg.Path()
+		return s.imports[i].Path() >= pkg.Path()
 	})
 	if i < len(s.imports) && s.imports[i] == pkg {
 		return