Create and use an NSTableView extension method: indexesOfAvailableRowsPassingTest.

Evergreen/MainWindow/Timeline/TimelineViewController.swift

@@ -331,19 +331,20 @@ class TimelineViewController: NSViewController, UndoableCommandRunner {
 			return
 		}
 
-		var indexes = IndexSet()
-		tableView.enumerateAvailableRowViews { (rowView, row) in
+		let indexesToReload = tableView.indexesOfAvailableRowsPassingTest { (row) -> Bool in
 			guard let article = articles.articleAtRow(row), let authors = article.authors, !authors.isEmpty else {
-				return
+				return false
 			}
 			for author in authors {
 				if author.avatarURL == avatarURL {
-					indexes.insert(row)
-					return
+					return true
 				}
 			}
+			return false
+		}
+		if let indexesToReload = indexesToReload {
+			reloadCells(for: indexesToReload)
 		}
-		reloadCells(for: indexes)
 	}
 
 	func fontSizeInDefaultsDidChange() {

Frameworks/RSCore/RSCore/NSTableView+Extensions.swift

@@ -16,6 +16,20 @@ public extension NSTableView {
 		}
 	}
 
+	func indexesOfAvailableRowsPassingTest(_ test: (Int) -> Bool) -> IndexSet? {
+
+		// Checks visible and in-flight rows.
+
+		var indexes = IndexSet()
+		enumerateAvailableRowViews { (_, row) in
+			if test(row) {
+				indexes.insert(row)
+			}
+		}
+
+		return indexes.isEmpty ? nil : indexes
+	}
+
 	func scrollTo(row: Int) {
 
 		guard let scrollView = self.enclosingScrollView else {