patch 8.2.3484: crash when going through spell suggestions

Problem:    Crash when going through spell suggestions.
Solution:   Limit the text length for finding suggestions to the original
            length.  Do not update buffers when exiting. (closes #8965)
diff --git a/src/testdir/test_spell_utf8.vim b/src/testdir/test_spell_utf8.vim
index 1f561e4..79dc3e4 100644
--- a/src/testdir/test_spell_utf8.vim
+++ b/src/testdir/test_spell_utf8.vim
@@ -765,4 +765,20 @@
   set spellfile=Xdir/Xtest.utf-8.add,Xtest_other.add
 endfunc
 
+func Test_no_crash_with_weird_text()
+  new
+  let lines =<< trim END
+      r<sfile>
+      €
+
+
+      €
+  END
+  call setline(1, lines)
+  exe "%norm \<C-v>ez=>\<C-v>wzG"
+
+  bwipe!
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab