fix: don't check skipped variant with internal tag

serde_derive/src/internals/check.rs

@@ -267,8 +267,10 @@ fn check_internal_tag_field_name_conflict(cx: &Ctxt, cont: &Container) {
         match variant.style {
             Style::Struct => {
                 for field in &variant.fields {
-                    let check_ser = !field.attrs.skip_serializing();
+                    let check_ser =
-                    let check_de = !field.attrs.skip_deserializing();
+                        !(field.attrs.skip_serializing() || variant.attrs.skip_serializing());
+                    let check_de =
+                        !(field.attrs.skip_deserializing() || variant.attrs.skip_deserializing());
                     let name = field.attrs.name();
                     let ser_name = name.serialize_name();
 

test_suite/tests/test_annotations.rs

@@ -2265,6 +2265,37 @@ fn test_externally_tagged_enum_containing_flatten() {
     );
 }
 
+#[test]
+fn test_internally_tagged_enum_with_skipped_conflict() {
+    #[derive(Serialize, Deserialize, PartialEq, Debug)]
+    #[serde(tag = "t")]
+    enum Data {
+        A,
+	#[serde(skip)]
+	B {
+	    t: String
+	},
+	C {
+	    #[serde(default, skip)]
+	    t: String
+	},
+    }
+
+    let _data = Data::B { t: "".to_string() };
+
+    let data = Data::C { t: "".to_string() };
+
+    assert_tokens(
+        &data,
+        &[
+            Token::Struct { name: "Data", len: 1 },
+            Token::Str("t"),
+            Token::Str("C"),
+            Token::StructEnd,
+        ],
+    );
+}
+
 #[test]
 fn test_internally_tagged_enum_containing_flatten() {
     #[derive(Serialize, Deserialize, PartialEq, Debug)]