Check distinct attachment names during datasource validation

webknossos-datastore/app/com/scalableminds/webknossos/datastore/models/datasource/DataLayer.scala

@@ -83,6 +83,8 @@ trait StaticLayer extends DataLayer {
 
   def numChannels: Int = if (elementClass == ElementClass.uint24) 3 else 1
 
+  def attachments: Option[DataLayerAttachments]
+
   def withMergedAndResolvedAttachments(dataSourcePath: UPath, attachments: DataLayerAttachments): StaticLayer =
     this match {
       case l: StaticSegmentationLayer =>

webknossos-datastore/app/com/scalableminds/webknossos/datastore/models/datasource/DataLayerAttachments.scala

@@ -45,6 +45,11 @@ case class DataLayerAttachments(
       connectomes = connectomes.map(_.relativizedIn(dataSourcePath)),
       cumsum = cumsum.map(_.relativizedIn(dataSourcePath))
     )
+
+  lazy val containsDuplicateNames: Boolean =
+    meshes.distinctBy(_.name).length != meshes.length ||
+      agglomerates.distinctBy(_.name).length != agglomerates.length ||
+      connectomes.distinctBy(_.name).length != connectomes.length
 }
 
 object DataLayerAttachments {

webknossos-datastore/app/com/scalableminds/webknossos/datastore/services/DataSourceValidation.scala

@@ -55,6 +55,10 @@ trait DataSourceValidation {
       check(
         dataSource.dataLayers.map(_.name).forall(!_.startsWith(".")),
         "Layer names must not start with dot."
+      ),
+      check(
+        dataSource.dataLayers.flatMap(_.attachments).forall(!_.containsDuplicateNames),
+        "Layer attachments must have unique names in their respective category."
       )
     ).flatten