vim-patch: b:changedtick-related patches

vim-patch:8.0.0334
vim-patch:8.0.0335
vim-patch:8.0.0343
vim-patch:8.0.0345

Problem:    Can't access b:changedtick from a dict reference.
Solution:   Make changedtick a member of the b: dict. (inspired by neovim
            vim/vim#6112)
79518e2ace

vim-patch:8.0.0343: b:changedtick can be unlocked
Problem:    b:changedtick can be unlocked, even though it has no effect.
            (Nikolai Pavlov)
Solution:   Add a check and error E940. (closes #1496)

vim-patch:8.0.0345: islocked('d.changedtick') does not work
Problem:    islocked('d.changedtick') does not work.
Solution:   Make it work.

vim-patch:8.0.0335: functions test fails
Problem:    Functions test fails.
Solution:   Use the right buffer number.
507647da31

src/nvim/testdir/Makefile

@@ -42,6 +42,7 @@ SCRIPTS ?= $(SCRIPTS_DEFAULT)
 NEW_TESTS ?= \
 	    test_autocmd.res \
 	    test_bufwintabinfo.res \
+	    test_changedtick.res \
 	    test_charsearch.res \
 	    test_cmdline.res \
 	    test_command_count.res \

src/nvim/testdir/test_alot.vim

@@ -2,9 +2,10 @@
 " This makes testing go faster, since Vim doesn't need to restart.
 
 source test_assign.vim
+source test_changedtick.vim
 source test_cursor_func.vim
-source test_execute_func.vim
 source test_ex_undo.vim
+source test_execute_func.vim
 source test_expr.vim
 source test_expr_utf8.vim
 source test_feedkeys.vim

src/nvim/testdir/test_changedtick.vim

@@ -0,0 +1,57 @@
+" Tests for b:changedtick
+
+func Test_changedtick_increments()
+  new
+  " New buffer has an empty line, tick starts at 2.
+  let expected = 2
+  call assert_equal(expected, b:changedtick)
+  call assert_equal(expected, b:['changedtick'])
+  call setline(1, 'hello')
+  let expected += 1
+  call assert_equal(expected, b:changedtick)
+  call assert_equal(expected, b:['changedtick'])
+  undo
+  " Somehow undo counts as two changes.
+  let expected += 2
+  call assert_equal(expected, b:changedtick)
+  call assert_equal(expected, b:['changedtick'])
+  bwipe!
+endfunc
+
+func Test_changedtick_dict_entry()
+  let d = b:
+  call assert_equal(b:changedtick, d['changedtick'])
+endfunc
+
+func Test_changedtick_bdel()
+  new
+  let bnr = bufnr('%')
+  let v = b:changedtick
+  bdel
+  " Delete counts as a change too.
+  call assert_equal(v + 1, getbufvar(bnr, 'changedtick'))
+endfunc
+
+func Test_changedtick_islocked()
+  call assert_equal(0, islocked('b:changedtick'))
+  let d = b:
+  call assert_equal(0, islocked('d.changedtick'))
+endfunc
+
+func Test_changedtick_fixed()
+  call assert_fails('let b:changedtick = 4', 'E46:')
+  call assert_fails('let b:["changedtick"] = 4', 'E46:')
+
+  call assert_fails('lockvar b:changedtick', 'E940:')
+  call assert_fails('lockvar b:["changedtick"]', 'E46:')
+  call assert_fails('unlockvar b:changedtick', 'E940:')
+  call assert_fails('unlockvar b:["changedtick"]', 'E46:')
+  call assert_fails('unlet b:changedtick', 'E795:')
+  call assert_fails('unlet b:["changedtick"]', 'E46:')
+
+  let d = b:
+  call assert_fails('lockvar d["changedtick"]', 'E46:')
+  call assert_fails('unlockvar d["changedtick"]', 'E46:')
+  call assert_fails('unlet d["changedtick"]', 'E46:')
+
+endfunc

src/nvim/testdir/test_functions.vim

@@ -311,3 +311,45 @@ func! Test_mode()
   bwipe!
   iunmap <F2>
 endfunc
+
+func Test_getbufvar()
+  let bnr = bufnr('%')
+  let b:var_num = '1234'
+  let def_num = '5678'
+  call assert_equal('1234', getbufvar(bnr, 'var_num'))
+  call assert_equal('1234', getbufvar(bnr, 'var_num', def_num))
+
+  let bd = getbufvar(bnr, '')
+  call assert_equal('1234', bd['var_num'])
+  call assert_true(exists("bd['changedtick']"))
+  call assert_equal(2, len(bd))
+
+  let bd2 = getbufvar(bnr, '', def_num)
+  call assert_equal(bd, bd2)
+
+  unlet b:var_num
+  call assert_equal(def_num, getbufvar(bnr, 'var_num', def_num))
+  call assert_equal('', getbufvar(bnr, 'var_num'))
+
+  let bd = getbufvar(bnr, '')
+  call assert_equal(1, len(bd))
+  let bd = getbufvar(bnr, '',def_num)
+  call assert_equal(1, len(bd))
+
+  call assert_equal('', getbufvar(9999, ''))
+  call assert_equal(def_num, getbufvar(9999, '', def_num))
+  unlet def_num
+
+  call assert_equal(0, getbufvar(bnr, '&autoindent'))
+  call assert_equal(0, getbufvar(bnr, '&autoindent', 1))
+
+  " Open new window with forced option values
+  set fileformats=unix,dos
+  new ++ff=dos ++bin ++enc=iso-8859-2
+  call assert_equal('dos', getbufvar(bufnr('%'), '&fileformat'))
+  call assert_equal(1, getbufvar(bufnr('%'), '&bin'))
+  call assert_equal('iso-8859-2', getbufvar(bufnr('%'), '&fenc'))
+  close
+
+  set fileformats&
+endfunc