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)

src/testdir/test_edit.vim

@@ -281,7 +281,7 @@ func Test_edit_11()
   call cursor(2, 1)
   call feedkeys("i\<c-f>int c;\<esc>", 'tnix')
   call cursor(3, 1)
-  call feedkeys("i/* comment */", 'tnix')
+  call feedkeys("\<Insert>/* comment */", 'tnix')
   call assert_equal(['{', "\<tab>int c;", "/* comment */"], getline(1, '$'))
   " added changed cindentkeys slightly
   set cindent cinkeys+=*/
@@ -1267,16 +1267,6 @@ func Test_edit_forbidden()
   catch /^Vim\%((\a\+)\)\=:E117/ " catch E117: unknown function
   endtry
   au! InsertCharPre
-  " Not allowed to enter ex mode when text is locked
-  au InsertCharPre <buffer> :normal! gQ<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
   " 3) edit when completion is shown
   fun! Complete(findstart, base)
     if a:findstart
@@ -1550,4 +1540,36 @@ func Test_edit_noesckeys()
   set esckeys
 endfunc
 
+" Test for running an invalid ex command in insert mode using CTRL-O
+" Note that vim has a hard-coded sleep of 3 seconds. So this test will take
+" more than 3 seconds to complete.
+func Test_edit_ctrl_o_invalid_cmd()
+  new
+  set showmode showcmd
+  let caught_e492 = 0
+  try
+    call feedkeys("i\<C-O>:invalid\<CR>abc\<Esc>", "xt")
+  catch /E492:/
+    let caught_e492 = 1
+  endtry
+  call assert_equal(1, caught_e492)
+  call assert_equal('abc', getline(1))
+  set showmode& showcmd&
+  close!
+endfunc
+
+" Test for inserting text at the beginning of a line
+func Test_insert_before_first_nonblank()
+  new
+  call setline(1, '    ')
+  normal! Ia
+  call assert_equal('    a', getline(1))
+  set cpo+=H
+  call setline(1, '    ')
+  normal! Ia
+  call assert_equal('   a ', getline(1))
+  set cpo-=H
+  close!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab