patch 8.2.0369: various Normal mode commands not fully tested

Problem:    Various Normal mode commands not fully tested.
Solution:   Add more tests. (Yegappan Lakshmanan, closes #5751)
diff --git a/src/testdir/test_gf.vim b/src/testdir/test_gf.vim
index 4a4ffce..829b7c2 100644
--- a/src/testdir/test_gf.vim
+++ b/src/testdir/test_gf.vim
@@ -130,5 +130,20 @@
   call setline(1, '/doesnotexist')
   call assert_fails('normal gf', 'E447:')
   call assert_fails('normal gF', 'E447:')
+  call assert_fails('normal [f', 'E447:')
+
+  " gf is not allowed when text is locked
+  au InsertCharPre <buffer> normal! gF<CR>
+  let caught_e523 = 0
+  try
+    call feedkeys("ix\<esc>", 'xt')
+  catch /^Vim\%((\a\+)\)\=:E523/ " catch E523
+    let caught_e523 = 1
+  endtry
+  call assert_equal(1, caught_e523)
+  au! InsertCharPre
+
   bwipe!
 endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab