Remove conflict between flatten and skip

serde_derive/src/de.rs

@@ -2456,7 +2456,7 @@ fn deserialize_map(
 
     let extract_collected = fields_names
         .iter()
-        .filter(|&&(field, _)| field.attrs.flatten())
+        .filter(|&&(field, _)| field.attrs.flatten() && !field.attrs.skip_deserializing())
         .map(|&(field, ref name)| {
             let field_ty = field.ty;
             let func = match field.attrs.deserialize_with() {

serde_derive/src/internals/check.rs

@@ -76,25 +76,6 @@ fn check_flatten_field(cx: &Ctxt, style: Style, field: &Field) {
         }
         _ => {}
     }
-    if field.attrs.skip_serializing() {
-        cx.error_spanned_by(
-            field.original,
-            "#[serde(flatten)] can not be combined with \
-             #[serde(skip_serializing)]",
-        );
-    } else if field.attrs.skip_serializing_if().is_some() {
-        cx.error_spanned_by(
-            field.original,
-            "#[serde(flatten)] can not be combined with \
-             #[serde(skip_serializing_if = \"...\")]",
-        );
-    } else if field.attrs.skip_deserializing() {
-        cx.error_spanned_by(
-            field.original,
-            "#[serde(flatten)] can not be combined with \
-             #[serde(skip_deserializing)]",
-        );
-    }
 }
 
 /// The `other` attribute must be used at most once and it must be the last