[css-grid-2] Close out issue about whether local line names combine with or obscure parent line names. #2622

Author: fantasai

css-grid-2/Overview.bs

@@ -154,12 +154,10 @@ Characteristics of a Subgrid Item</h3>
 		<li>
 			Since <a>subgrids</a> can be placed before their contents are placed,
 			the subgridded lines
-			automatically receive the line names specified on the parent <a>grid</a>.
-
-			ISSUE: If a <<line-name-list>> is provided,
-			should this hide the names received from the parent
-			or be in addition to those names?
-			(<a href="https://github.com/w3c/csswg-drafts/issues/2622">Issue 2622</a>)
+			automatically receive the line names
+			specified on the corresponding lines of the parent <a>grid</a>.
+			These names are in <em>addition</em> to
+			any line names specified locally on the subgrid.
 
 		<li>
 			The <a>subgrid</a> itself lays out as an ordinary <a>grid item</a> in its parent grid,