patch 8.2.2496: insufficien testing for text jumping fix

Problem:    Insufficien testing for text jumping fix.
Solution:   Add another test case.
diff --git a/src/testdir/test_breakindent.vim b/src/testdir/test_breakindent.vim
index 98aff02..bb0f6dd 100644
--- a/src/testdir/test_breakindent.vim
+++ b/src/testdir/test_breakindent.vim
@@ -634,15 +634,20 @@
   call s:compare_lines(expect, lines)
   " Scroll down one screen line
   setl scrolloff=5
-  norm! 6gj
-  redraw!
+  norm! 5gj
   let lines = s:screen_lines(1, 20)
   let expect = [
-	\ "> aaaaaaaaaaaaaaaaaa",
+	\ "aaaaaaaaaaaaaaaaaaaa",
 	\ "> aaaaaaaaaaaaaaaaaa",
 	\ "> aaaaaaaaaaaaaaaaaa",
 	\ ]
   call s:compare_lines(expect, lines)
+  redraw!
+  " moving the cursor doesn't change the text offset
+  norm! l
+  redraw!
+  let lines = s:screen_lines(1, 20)
+  call s:compare_lines(expect, lines)
 
   setl breakindent briopt=min:18 sbr=>
   norm! 5gj