patch 8.1.0002: :stopinsert changes the message position

Problem:    :stopinsert changes the message position.
Solution:   Save and restore msg_col and msg_row in clearmode(). (Jason
            Franklin)

src/screen.c

@@ -10485,10 +10485,16 @@ unshowmode(int force)
    void
clearmode(void)
{
    int save_msg_row = msg_row;
    int save_msg_col = msg_col;

    msg_pos_mode();
    if (Recording)
	recording_mode(HL_ATTR(HLF_CM));
    msg_clr_eos();

    msg_col = save_msg_col;
    msg_row = save_msg_row;
}

    static void

src/testdir/test_messages.vim

@@ -38,3 +38,24 @@ function Test_messages()
    let &more = oldmore
  endtry
endfunction

" Patch 7.4.1696 defined the "clearmode()" command for clearing the mode
" indicator (e.g., "-- INSERT --") when ":stopinsert" is invoked.  Message
" output could then be disturbed when 'cmdheight' was greater than one.
" This test ensures that the bugfix for this issue remains in place.
function! Test_stopinsert_does_not_break_message_output()
  set cmdheight=2
  redraw!

  stopinsert | echo 'test echo'
  call assert_equal(116, screenchar(&lines - 1, 1))
  call assert_equal(32, screenchar(&lines, 1))
  redraw!

  stopinsert | echomsg 'test echomsg'
  call assert_equal(116, screenchar(&lines - 1, 1))
  call assert_equal(32, screenchar(&lines, 1))
  redraw!

  set cmdheight&
endfunction

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =

static int included_patches[] =
{   /* Add new patch number below this line */
/**/
    2,
/**/
    1,
/**/