patch 8.0.0133
Problem:    "2;'(" causes ml_get errors in an empty buffer.  (Dominique Pelle)
Solution:   Check the cursor line earlier.
diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index c48a811..96fee0b 100644
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -234,3 +234,10 @@
   call feedkeys(":abc def\<S-Left>\<C-U>\<C-B>\"\<CR>", 'tx')
   call assert_equal('"def', @:)
 endfunc
+
+func Test_illegal_address()
+  new
+  2;'(
+  2;')
+  quit
+endfunc