Fix #1487 (#1488)

CHANGELOG.md

@@ -1,3 +1,6 @@
+## [8.1.1]
+- Fix null error in line.dart [#1487](https://github.com/singerdmx/flutter-quill/issues/1487)
+
 ## [8.1.0]
 - Fixes a word typo of `mirgration` to `migration` in readme & migration document.
 - Updated migration guide

lib/src/models/documents/nodes/line.dart

@@ -182,12 +182,12 @@ class Line extends Container<Leaf?> {
 
       // nextLine might have been unmounted since last assert so we need to
       // check again we still have a line after us.
-      assert(nextLine != null);
-
-      // Move remaining children in this line to the next line so that all
-      // attributes of nextLine are preserved.
-      nextLine!.moveChildToNewParent(this);
-      moveChildToNewParent(nextLine);
+      if (nextLine != null) {
+        // Move remaining children in this line to the next line so that all
+        // attributes of nextLine are preserved.
+        nextLine?.moveChildToNewParent(this);
+        moveChildToNewParent(nextLine);
+      }
     }
 
     if (isLFDeleted) {

pubspec.yaml

@@ -1,6 +1,6 @@
 name: flutter_quill
 description: A rich text editor built for the modern Android, iOS, web and desktop platforms. It is the WYSIWYG editor and a Quill component for Flutter.
-version: 8.1.0
+version: 8.1.1
 homepage: https://1o24bbs.com/c/bulletjournal/108
 repository: https://github.com/singerdmx/flutter-quill
 topics: