fix: layer with shared encoding ignore repeater

src/normalize/core.ts

@@ -68,7 +68,6 @@ export class CoreNormalizer extends SpecMapper<NormalizerParams, FacetedUnitSpec
       ...(spec.name ? {name: [params.repeaterPrefix, spec.name].filter(n => n).join('_')} : {}),
       ...(encoding ? {encoding} : {})
     };
-
     if (parentEncoding || parentProjection) {
       return this.mapUnitWithParentEncodingOrProjection(specWithReplacedEncoding, params);
     }
@@ -212,6 +211,7 @@ export class CoreNormalizer extends SpecMapper<NormalizerParams, FacetedUnitSpec
 
     return super.mapFacet(spec, params);
   }
+  //
 
   private mapUnitWithParentEncodingOrProjection(
     spec: FacetedUnitSpec<Field>,
@@ -224,14 +224,21 @@ export class CoreNormalizer extends SpecMapper<NormalizerParams, FacetedUnitSpec
       parentEncoding,
       encoding: replaceRepeaterInEncoding(encoding, params.repeater)
     });
-
     return this.mapUnit(
       {
         ...spec,
         ...(mergedProjection ? {projection: mergedProjection} : {}),
         ...(mergedEncoding ? {encoding: mergedEncoding} : {})
       },
-      {config}
+      emptyFlag(encoding) && !emptyFlag(params.repeater)
+        ? {
+            ...params,
+            config: config,
+            repeater: params.repeater
+          }
+        : {
+            config
+          }
     );
   }
 
@@ -398,3 +405,10 @@ function mergeProjection<ES extends ExprRef | SignalRef>(opt: {
   }
   return projection ?? parentProjection;
 }
+
+function emptyFlag(obj: any) {
+  if (obj == null) {
+    return true;
+  }
+  return Object.keys(obj).length === 0;
+}