bugfix; was passing extraneous props into LabIcon.resolveX methods

packages/apputils/src/toolbar.tsx

@@ -496,7 +496,8 @@ export function ToolbarButtonComponent(props: ToolbarButtonComponent.IProps) {
       minimal
     >
       <LabIcon.resolveReact
-        {...props}
+        icon={props.icon}
+        iconClass={props.iconClass}
         className={
           // if props.icon is unset, add extra classes for proper support of icon-as-css-background
           props.icon

packages/filebrowser/src/listing.ts

@@ -1844,7 +1844,11 @@ export namespace DirListing {
         // no icon set on fileType, fall back to default file icon
         fileIcon.element(iconProps);
       } else {
-        LabIcon.resolveElement({ ...fileType, ...iconProps });
+        LabIcon.resolveElement({
+          icon: fileType.icon,
+          iconClass: fileType.iconClass,
+          ...iconProps
+        });
       }
 
       let hoverText = 'Name: ' + model.name;