patch 8.1.0009: tabpages insufficiently tested

Problem:    Tabpages insufficiently tested.
Solution:   Add more test coverage. (Dominique Pelle, closes #2934)

src/testdir/test_tabpage.vim

@@ -1,5 +1,6 @@
" Tests for tabpage


function Test_tabpage()
  bw!
  " Simple test for opening and closing a tab page
@@ -317,6 +318,34 @@ function s:reconstruct_tabpage_for_test(nr)
  endfor
endfunc

func Test_tabpage_ctrl_pgup_pgdown()
  enew!
  tabnew tab1
  tabnew tab2

  call assert_equal(3, tabpagenr())
  exe "norm! \<C-PageUp>"
  call assert_equal(2, tabpagenr())
  exe "norm! \<C-PageDown>"
  call assert_equal(3, tabpagenr())

  " Check wrapping at last or first page.
  exe "norm! \<C-PageDown>"
  call assert_equal(1, tabpagenr())
  exe "norm! \<C-PageUp>"
  call assert_equal(3, tabpagenr())

 " With a count, <C-PageUp> and <C-PageDown> are not symmetrical somehow:
 " - {count}<C-PageUp> goes {count} pages downward (relative count)
 " - {count}<C-PageDown> goes to page number {count} (absolute count)
  exe "norm! 2\<C-PageUp>"
  call assert_equal(1, tabpagenr())
  exe "norm! 2\<C-PageDown>"
  call assert_equal(2, tabpagenr())

  1tabonly!
endfunc

" Test for [count] of tabclose
function Test_tabpage_with_tabclose()

@@ -491,4 +520,18 @@ func Test_close_on_quitpre()
  buf Xtest
endfunc

func Test_tabs()
  enew!
  tabnew tab1
  norm ixxx
  let a=split(execute(':tabs'), "\n")
  call assert_equal(['Tab page 1',
      \              '    [No Name]',
      \              'Tab page 2',
      \              '> + tab1'], a)

  1tabonly!
  bw!
endfunc

" vim: shiftwidth=2 sts=2 expandtab

src/version.c

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

static int included_patches[] =
{   /* Add new patch number below this line */
/**/
    9,
/**/
    8,
/**/