Adding upstream version 2:9.1.0199.upstream/2%9.1.0199

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3286 insertions, 0 deletions

diff --git a/src/testdir/test_winfixbuf.vim b/src/testdir/test_winfixbuf.vim
new file mode 100644
index 0000000..04043f8
--- /dev/null
+++ b/src/testdir/test_winfixbuf.vim
@@ -0,0 +1,3286 @@
+" Test 'winfixbuf'
+
+source check.vim
+
+" Find the number of open windows in the current tab
+func s:get_windows_count()
+  return tabpagewinnr(tabpagenr(), '$')
+endfunc
+
+" Create some unnamed buffers.
+func s:make_buffers_list()
+  enew
+  file first
+  let l:first = bufnr()
+
+  enew
+  file middle
+  let l:middle = bufnr()
+
+  enew
+  file last
+  let l:last = bufnr()
+
+  set winfixbuf
+
+  return [l:first, l:last]
+endfunc
+
+" Create some unnamed buffers and add them to an args list
+func s:make_args_list()
+  let [l:first, l:last] = s:make_buffers_list()
+
+  args! first middle last
+
+  return [l:first, l:last]
+endfunc
+
+" Create two buffers and then set the window to 'winfixbuf'
+func s:make_buffer_pairs(...)
+  let l:reversed = get(a:, 1, 0)
+
+  if l:reversed == 1
+    enew
+    file original
+
+    set winfixbuf
+
+    enew!
+    file other
+    let l:other = bufnr()
+
+    return l:other
+  endif
+
+  enew
+  file other
+  let l:other = bufnr()
+
+  enew
+  file current
+
+  set winfixbuf
+
+  return l:other
+endfunc
+
+" Create 3 quick buffers and set the window to 'winfixbuf'
+func s:make_buffer_trio()
+  edit first
+  let l:first = bufnr()
+  edit second
+  let l:second = bufnr()
+
+  set winfixbuf
+
+  edit! third
+  let l:third = bufnr()
+
+  execute ":buffer! " . l:second
+
+  return [l:first, l:second, l:third]
+endfunc
+
+" Create a location list with at least 2 entries + a 'winfixbuf' window.
+func s:make_simple_location_list()
+  enew
+  file middle
+  let l:middle = bufnr()
+  call append(0, ["winfix search-term", "another line"])
+
+  enew!
+  file first
+  let l:first = bufnr()
+  call append(0, "first search-term")
+
+  enew!
+  file last
+  let l:last = bufnr()
+  call append(0, "last search-term")
+
+  call setloclist(
+  \  0,
+  \  [
+  \    {
+  \      "filename": "first",
+  \      "bufnr": l:first,
+  \      "lnum": 1,
+  \    },
+  \    {
+  \      "filename": "middle",
+  \      "bufnr": l:middle,
+  \      "lnum": 1,
+  \    },
+  \    {
+  \      "filename": "middle",
+  \      "bufnr": l:middle,
+  \      "lnum": 2,
+  \    },
+  \    {
+  \      "filename": "last",
+  \      "bufnr": l:last,
+  \      "lnum": 1,
+  \    },
+  \  ]
+  \)
+
+  set winfixbuf
+
+  return [l:first, l:middle, l:last]
+endfunc
+
+" Create a quickfix with at least 2 entries that are in the current 'winfixbuf' window.
+func s:make_simple_quickfix()
+  enew
+  file current
+  let l:current = bufnr()
+  call append(0, ["winfix search-term", "another line"])
+
+  enew!
+  file first
+  let l:first = bufnr()
+  call append(0, "first search-term")
+
+  enew!
+  file last
+  let l:last = bufnr()
+  call append(0, "last search-term")
+
+  call setqflist(
+  \  [
+  \    {
+  \      "filename": "first",
+  \      "bufnr": l:first,
+  \      "lnum": 1,
+  \    },
+  \    {
+  \      "filename": "current",
+  \      "bufnr": l:current,
+  \      "lnum": 1,
+  \    },
+  \    {
+  \      "filename": "current",
+  \      "bufnr": l:current,
+  \      "lnum": 2,
+  \    },
+  \    {
+  \      "filename": "last",
+  \      "bufnr": l:last,
+  \      "lnum": 1,
+  \    },
+  \  ]
+  \)
+
+  set winfixbuf
+
+  return [l:current, l:last]
+endfunc
+
+" Create a quickfix with at least 2 entries that are in the current 'winfixbuf' window.
+func s:make_quickfix_windows()
+  let [l:current, _] = s:make_simple_quickfix()
+  execute "buffer! " . l:current
+
+  split
+  let l:first_window = win_getid()
+  execute "normal \<C-w>j"
+  let l:winfix_window = win_getid()
+
+  " Open the quickfix in a separate split and go to it
+  copen
+  let l:quickfix_window = win_getid()
+
+  return [l:first_window, l:winfix_window, l:quickfix_window]
+endfunc
+
+" Revert all changes that occurred in any past test
+func s:reset_all_buffers()
+  %bwipeout!
+  set nowinfixbuf
+
+  call setqflist([])
+
+  for l:window_info in getwininfo()
+    call setloclist(l:window_info["winid"], [])
+  endfor
+
+  delmarks A-Z0-9
+endfunc
+
+" Find and set the first quickfix entry that points to `buffer`
+func s:set_quickfix_by_buffer(buffer)
+  let l:index = 1  " quickfix indices start at 1
+  for l:entry in getqflist()
+    if l:entry["bufnr"] == a:buffer
+      execute l:index . "cc"
+
+      return
+    endif
+
+    let l:index += 1
+  endfor
+
+  echoerr 'No quickfix entry matching "' . a:buffer . '" could be found.'
+endfunc
+
+" Fail to call :Next on a 'winfixbuf' window unless :Next! is used.
+func Test_Next()
+  call s:reset_all_buffers()
+
+  let [l:first, _] = s:make_args_list()
+  next!
+
+  call assert_fails("Next", "E1513:")
+  call assert_notequal(l:first, bufnr())
+
+  Next!
+  call assert_equal(l:first, bufnr())
+endfunc
+
+" Call :argdo and choose the next available 'nowinfixbuf' window.
+func Test_argdo_choose_available_window()
+  call s:reset_all_buffers()
+
+  let [_, l:last] = s:make_args_list()
+
+  " Make a split window that is 'nowinfixbuf' but make it the second-to-last
+  " window so that :argdo will first try the 'winfixbuf' window, pass over it,
+  " and prefer the other 'nowinfixbuf' window, instead.
+  "
+  " +-------------------+
+  " |   'nowinfixbuf'   |
+  " +-------------------+
+  " |    'winfixbuf'    |  <-- Cursor is here
+  " +-------------------+
+  split
+  let l:nowinfixbuf_window = win_getid()
+  " Move to the 'winfixbuf' window now
+  execute "normal \<C-w>j"
+  let l:winfixbuf_window = win_getid()
+  let l:expected_windows = s:get_windows_count()
+
+  argdo echo ''
+  call assert_equal(l:nowinfixbuf_window, win_getid())
+  call assert_equal(l:last, bufnr())
+  call assert_equal(l:expected_windows, s:get_windows_count())
+endfunc
+
+" Call :argdo and create a new split window if all available windows are 'winfixbuf'.
+func Test_argdo_make_new_window()
+  call s:reset_all_buffers()
+
+  let [l:first, l:last] = s:make_args_list()
+  let l:current = win_getid()
+  let l:current_windows = s:get_windows_count()
+
+  argdo echo ''
+  call assert_notequal(l:current, win_getid())
+  call assert_equal(l:last, bufnr())
+  execute "normal \<C-w>j"
+  call assert_equal(l:first, bufnr())
+  call assert_equal(l:current_windows + 1, s:get_windows_count())
+endfunc
+
+" Fail :argedit but :argedit! is allowed
+func Test_argedit()
+  call s:reset_all_buffers()
+
+  args! first middle last
+  enew
+  file first
+  let l:first = bufnr()
+
+  enew
+  file middle
+  let l:middle = bufnr()
+
+  enew
+  file last
+  let l:last = bufnr()
+
+  set winfixbuf
+
+  let l:current = bufnr()
+  call assert_fails("argedit first middle last", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  argedit! first middle last
+  call assert_equal(l:first, bufnr())
+endfunc
+
+" Fail :arglocal but :arglocal! is allowed
+func Test_arglocal()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+  argglobal! other
+  execute "buffer! " . l:current
+
+  call assert_fails("arglocal other", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  arglocal! other
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :argglobal but :argglobal! is allowed
+func Test_argglobal()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("argglobal other", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  argglobal! other
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :args but :args! is allowed
+func Test_args()
+  call s:reset_all_buffers()
+
+  let [l:first, _] = s:make_buffers_list()
+  let l:current = bufnr()
+
+  call assert_fails("args first middle last", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  args! first middle last
+  call assert_equal(l:first, bufnr())
+endfunc
+
+" Fail :bNext but :bNext! is allowed
+func Test_bNext()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  call assert_fails("bNext", "E1513:")
+  let l:current = bufnr()
+
+  call assert_equal(l:current, bufnr())
+
+  bNext!
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Allow :badd because it doesn't actually change the current window's buffer
+func Test_badd()
+  call s:reset_all_buffers()
+
+  call s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  badd other
+  call assert_equal(l:current, bufnr())
+endfunc
+
+" Allow :balt because it doesn't actually change the current window's buffer
+func Test_balt()
+  call s:reset_all_buffers()
+
+  call s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  balt other
+  call assert_equal(l:current, bufnr())
+endfunc
+
+" Fail :bfirst but :bfirst! is allowed
+func Test_bfirst()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("bfirst", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  bfirst!
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :blast but :blast! is allowed
+func Test_blast()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs(1)
+  bfirst!
+  let l:current = bufnr()
+
+  call assert_fails("blast", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  blast!
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :bmodified but :bmodified! is allowed
+func Test_bmodified()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  execute "buffer! " . l:other
+  set modified
+  execute "buffer! " . l:current
+
+  call assert_fails("bmodified", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  bmodified!
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :bnext but :bnext! is allowed
+func Test_bnext()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("bnext", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  bnext!
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :bprevious but :bprevious! is allowed
+func Test_bprevious()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("bprevious", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  bprevious!
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :brewind but :brewind! is allowed
+func Test_brewind()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("brewind", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  brewind!
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :browse edit but :browse edit! is allowed
+func Test_browse_edit_fail()
+  " A GUI dialog may stall the test.
+  CheckNotGui
+
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("browse edit other", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  try
+    browse edit! other
+    call assert_equal(l:other, bufnr())
+  catch /^Vim\%((\a\+)\)\=:E338:/
+    " Ignore E338, which occurs if console Vim is built with +browse.
+    " Console Vim without +browse will treat this as a regular :edit.
+  endtry
+endfunc
+
+" Allow :browse w because it doesn't change the buffer in the current file
+func Test_browse_edit_pass()
+  " A GUI dialog may stall the test.
+  CheckNotGui
+
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  try
+    browse write other
+  catch /^Vim\%((\a\+)\)\=:E338:/
+    " Ignore E338, which occurs if console Vim is built with +browse.
+    " Console Vim without +browse will treat this as a regular :write.
+  endtry
+
+  call delete("other")
+endfunc
+
+" Call :bufdo and choose the next available 'nowinfixbuf' window.
+func Test_bufdo_choose_available_window()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+
+  " Make a split window that is 'nowinfixbuf' but make it the second-to-last
+  " window so that :bufdo will first try the 'winfixbuf' window, pass over it,
+  " and prefer the other 'nowinfixbuf' window, instead.
+  "
+  " +-------------------+
+  " |   'nowinfixbuf'   |
+  " +-------------------+
+  " |    'winfixbuf'    |  <-- Cursor is here
+  " +-------------------+
+  split
+  let l:nowinfixbuf_window = win_getid()
+  " Move to the 'winfixbuf' window now
+  execute "normal \<C-w>j"
+  let l:winfixbuf_window = win_getid()
+
+  let l:current = bufnr()
+  let l:expected_windows = s:get_windows_count()
+
+  call assert_notequal(l:current, l:other)
+
+  bufdo echo ''
+  call assert_equal(l:nowinfixbuf_window, win_getid())
+  call assert_notequal(l:other, bufnr())
+  call assert_equal(l:expected_windows, s:get_windows_count())
+endfunc
+
+" Call :bufdo and create a new split window if all available windows are 'winfixbuf'.
+func Test_bufdo_make_new_window()
+  call s:reset_all_buffers()
+
+  let [l:first, l:last] = s:make_buffers_list()
+  execute "buffer! " . l:first
+  let l:current = win_getid()
+  let l:current_windows = s:get_windows_count()
+
+  bufdo echo ''
+  call assert_notequal(l:current, win_getid())
+  call assert_equal(l:last, bufnr())
+  execute "normal \<C-w>j"
+  call assert_equal(l:first, bufnr())
+  call assert_equal(l:current_windows + 1, s:get_windows_count())
+endfunc
+
+" Fail :buffer but :buffer! is allowed
+func Test_buffer()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("buffer " . l:other, "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  execute "buffer! " . l:other
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Allow :buffer on a 'winfixbuf' window if there is no change in buffer
+func Test_buffer_same_buffer()
+  call s:reset_all_buffers()
+
+  call s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  execute "buffer " . l:current
+  call assert_equal(l:current, bufnr())
+
+  execute "buffer! " . l:current
+  call assert_equal(l:current, bufnr())
+endfunc
+
+" Allow :cNext but the 'nowinfixbuf' window is selected, instead
+func Test_cNext()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first_window, l:winfix_window, l:quickfix_window] = s:make_quickfix_windows()
+
+  " The call to `:cNext` succeeds but it selects the window with 'nowinfixbuf' instead
+  call s:set_quickfix_by_buffer(winbufnr(l:winfix_window))
+
+  " Make sure the previous window has 'winfixbuf' so we can test that our
+  " "skip 'winfixbuf' window" logic works.
+  call win_gotoid(l:winfix_window)
+  call win_gotoid(l:quickfix_window)
+
+  cNext
+  call assert_equal(l:first_window, win_getid())
+endfunc
+
+" Allow :cNfile but the 'nowinfixbuf' window is selected, instead
+func Test_cNfile()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first_window, l:winfix_window, l:quickfix_window] = s:make_quickfix_windows()
+
+  " The call to `:cNfile` succeeds but it selects the window with 'nowinfixbuf' instead
+  call s:set_quickfix_by_buffer(winbufnr(l:winfix_window))
+  cnext!
+
+  " Make sure the previous window has 'winfixbuf' so we can test that our
+  " "skip 'winfixbuf' window" logic works.
+  call win_gotoid(l:winfix_window)
+  call win_gotoid(l:quickfix_window)
+
+  cNfile
+  call assert_equal(l:first_window, win_getid())
+endfunc
+
+" Allow :caddexpr because it doesn't change the current buffer
+func Test_caddexpr()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let l:file_path = tempname()
+  call writefile(["Error - bad-thing-found"], l:file_path)
+  execute "edit " . l:file_path
+  let l:file_buffer = bufnr()
+  let l:current = bufnr()
+
+  edit first.unittest
+  call append(0, ["some-search-term bad-thing-found"])
+
+  edit! other.unittest
+
+  set winfixbuf
+
+  execute "buffer! " . l:file_buffer
+
+  execute 'caddexpr expand("%") .. ":" .. line(".") .. ":" .. getline(".")'
+  call assert_equal(l:current, bufnr())
+
+  call delete(l:file_path)
+endfunc
+
+" Fail :cbuffer but :cbuffer! is allowed
+func Test_cbuffer()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let l:file_path = tempname()
+  call writefile(["first.unittest:1:Error - bad-thing-found"], l:file_path)
+  execute "edit " . l:file_path
+  let l:file_buffer = bufnr()
+  let l:current = bufnr()
+
+  edit first.unittest
+  call append(0, ["some-search-term bad-thing-found"])
+
+  edit! other.unittest
+
+  set winfixbuf
+
+  execute "buffer! " . l:file_buffer
+
+  call assert_fails("cbuffer " . l:file_buffer)
+  call assert_equal(l:current, bufnr())
+
+  execute "cbuffer! " . l:file_buffer
+  call assert_equal("first.unittest", expand("%:t"))
+
+  call delete(l:file_path)
+endfunc
+
+" Allow :cc but the 'nowinfixbuf' window is selected, instead
+func Test_cc()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first_window, l:winfix_window, l:quickfix_window] = s:make_quickfix_windows()
+
+  " The call to `:cnext` succeeds but it selects the window with 'nowinfixbuf' instead
+  call s:set_quickfix_by_buffer(winbufnr(l:winfix_window))
+
+  " Make sure the previous window has 'winfixbuf' so we can test that our
+  " "skip 'winfixbuf' window" logic works.
+  call win_gotoid(l:winfix_window)
+  call win_gotoid(l:quickfix_window)
+  " Go up one line in the quickfix window to an quickfix entry that doesn't
+  " point to a winfixbuf buffer
+  normal k
+  " Attempt to make the previous window, winfixbuf buffer, to go to the
+  " non-winfixbuf quickfix entry
+  .cc
+
+  " Confirm that :.cc did not change the winfixbuf-enabled window
+  call assert_equal(l:first_window, win_getid())
+endfunc
+
+" Call :cdo and choose the next available 'nowinfixbuf' window.
+func Test_cdo_choose_available_window()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:current, l:last] = s:make_simple_quickfix()
+  execute "buffer! " . l:current
+
+  " Make a split window that is 'nowinfixbuf' but make it the second-to-last
+  " window so that :cdo will first try the 'winfixbuf' window, pass over it,
+  " and prefer the other 'nowinfixbuf' window, instead.
+  "
+  " +-------------------+
+  " |   'nowinfixbuf'   |
+  " +-------------------+
+  " |    'winfixbuf'    |  <-- Cursor is here
+  " +-------------------+
+  split
+  let l:nowinfixbuf_window = win_getid()
+  " Move to the 'winfixbuf' window now
+  execute "normal \<C-w>j"
+  let l:winfixbuf_window = win_getid()
+  let l:expected_windows = s:get_windows_count()
+
+  cdo echo ''
+
+  call assert_equal(l:nowinfixbuf_window, win_getid())
+  call assert_equal(l:last, bufnr())
+  execute "normal \<C-w>j"
+  call assert_equal(l:current, bufnr())
+  call assert_equal(l:expected_windows, s:get_windows_count())
+endfunc
+
+" Call :cdo and create a new split window if all available windows are 'winfixbuf'.
+func Test_cdo_make_new_window()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:current_buffer, l:last] = s:make_simple_quickfix()
+  execute "buffer! " . l:current_buffer
+
+  let l:current_window = win_getid()
+  let l:current_windows = s:get_windows_count()
+
+  cdo echo ''
+  call assert_notequal(l:current_window, win_getid())
+  call assert_equal(l:last, bufnr())
+  execute "normal \<C-w>j"
+  call assert_equal(l:current_buffer, bufnr())
+  call assert_equal(l:current_windows + 1, s:get_windows_count())
+endfunc
+
+" Fail :cexpr but :cexpr! is allowed
+func Test_cexpr()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let l:file = tempname()
+  let l:entry = '["' . l:file . ':1:bar"]'
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  call assert_fails("cexpr " . l:entry)
+  call assert_equal(l:current, bufnr())
+
+  execute "cexpr! " . l:entry
+  call assert_equal(fnamemodify(l:file, ":t"), expand("%:t"))
+endfunc
+
+" Call :cfdo and choose the next available 'nowinfixbuf' window.
+func Test_cfdo_choose_available_window()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:current, l:last] = s:make_simple_quickfix()
+  execute "buffer! " . l:current
+
+  " Make a split window that is 'nowinfixbuf' but make it the second-to-last
+  " window so that :cfdo will first try the 'winfixbuf' window, pass over it,
+  " and prefer the other 'nowinfixbuf' window, instead.
+  "
+  " +-------------------+
+  " |   'nowinfixbuf'   |
+  " +-------------------+
+  " |    'winfixbuf'    |  <-- Cursor is here
+  " +-------------------+
+  split
+  let l:nowinfixbuf_window = win_getid()
+  " Move to the 'winfixbuf' window now
+  execute "normal \<C-w>j"
+  let l:winfixbuf_window = win_getid()
+  let l:expected_windows = s:get_windows_count()
+
+  cfdo echo ''
+
+  call assert_equal(l:nowinfixbuf_window, win_getid())
+  call assert_equal(l:last, bufnr())
+  execute "normal \<C-w>j"
+  call assert_equal(l:current, bufnr())
+  call assert_equal(l:expected_windows, s:get_windows_count())
+endfunc
+
+" Call :cfdo and create a new split window if all available windows are 'winfixbuf'.
+func Test_cfdo_make_new_window()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:current_buffer, l:last] = s:make_simple_quickfix()
+  execute "buffer! " . l:current_buffer
+
+  let l:current_window = win_getid()
+  let l:current_windows = s:get_windows_count()
+
+  cfdo echo ''
+  call assert_notequal(l:current_window, win_getid())
+  call assert_equal(l:last, bufnr())
+  execute "normal \<C-w>j"
+  call assert_equal(l:current_buffer, bufnr())
+  call assert_equal(l:current_windows + 1, s:get_windows_count())
+endfunc
+
+" Fail :cfile but :cfile! is allowed
+func Test_cfile()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  edit first.unittest
+  call append(0, ["some-search-term bad-thing-found"])
+  write
+  let l:first = bufnr()
+
+  edit! second.unittest
+  call append(0, ["some-search-term"])
+  write
+
+  let l:file = tempname()
+  call writefile(["first.unittest:1:Error - bad-thing-found was detected"], l:file)
+
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  call assert_fails(":cfile " . l:file)
+  call assert_equal(l:current, bufnr())
+
+  execute ":cfile! " . l:file
+  call assert_equal(l:first, bufnr())
+
+  call delete(l:file)
+  call delete("first.unittest")
+  call delete("second.unittest")
+endfunc
+
+" Allow :cfirst but the 'nowinfixbuf' window is selected, instead
+func Test_cfirst()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first_window, l:winfix_window, l:quickfix_window] = s:make_quickfix_windows()
+
+  " The call to `:cfirst` succeeds but it selects the window with 'nowinfixbuf' instead
+  call s:set_quickfix_by_buffer(winbufnr(l:winfix_window))
+
+  " Make sure the previous window has 'winfixbuf' so we can test that our
+  " "skip 'winfixbuf' window" logic works.
+  call win_gotoid(l:winfix_window)
+  call win_gotoid(l:quickfix_window)
+
+  cfirst
+  call assert_equal(l:first_window, win_getid())
+endfunc
+
+" Allow :clast but the 'nowinfixbuf' window is selected, instead
+func Test_clast()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first_window, l:winfix_window, l:quickfix_window] = s:make_quickfix_windows()
+
+  " The call to `:clast` succeeds but it selects the window with 'nowinfixbuf' instead
+  call s:set_quickfix_by_buffer(winbufnr(l:winfix_window))
+
+  " Make sure the previous window has 'winfixbuf' so we can test that our
+  " "skip 'winfixbuf' window" logic works.
+  call win_gotoid(l:winfix_window)
+  call win_gotoid(l:quickfix_window)
+
+  clast
+  call assert_equal(l:first_window, win_getid())
+endfunc
+
+" Allow :cnext but the 'nowinfixbuf' window is selected, instead
+" Make sure no new windows are created and previous windows are reused
+func Test_cnext()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first_window, l:winfix_window, l:quickfix_window] = s:make_quickfix_windows()
+  let l:expected = s:get_windows_count()
+
+  " The call to `:cnext` succeeds but it selects the window with 'nowinfixbuf' instead
+  call s:set_quickfix_by_buffer(winbufnr(l:winfix_window))
+
+  cnext!
+  call assert_equal(l:expected, s:get_windows_count())
+
+  " Make sure the previous window has 'winfixbuf' so we can test that our
+  " "skip 'winfixbuf' window" logic works.
+  call win_gotoid(l:winfix_window)
+  call win_gotoid(l:quickfix_window)
+
+  cnext
+  call assert_equal(l:first_window, win_getid())
+  call assert_equal(l:expected, s:get_windows_count())
+endfunc
+
+" Make sure :cnext creates a split window if no previous window exists
+func Test_cnext_no_previous_window()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:current, _] = s:make_simple_quickfix()
+  execute "buffer! " . l:current
+
+  let l:expected = s:get_windows_count()
+
+  " Open the quickfix in a separate split and go to it
+  copen
+
+  call assert_equal(l:expected + 1, s:get_windows_count())
+endfunc
+
+" Allow :cnext and create a 'nowinfixbuf' window if none exists
+func Test_cnext_make_new_window()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:current, _] = s:make_simple_quickfix()
+  let l:current = win_getid()
+
+  cfirst!
+
+  let l:windows = s:get_windows_count()
+  let l:expected = l:windows + 1  " We're about to create a new split window
+
+  cnext
+  call assert_equal(l:expected, s:get_windows_count())
+
+  cnext!
+  call assert_equal(l:expected, s:get_windows_count())
+endfunc
+
+" Allow :cprevious but the 'nowinfixbuf' window is selected, instead
+func Test_cprevious()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first_window, l:winfix_window, l:quickfix_window] = s:make_quickfix_windows()
+
+  " The call to `:cprevious` succeeds but it selects the window with 'nowinfixbuf' instead
+  call s:set_quickfix_by_buffer(winbufnr(l:winfix_window))
+
+  " Make sure the previous window has 'winfixbuf' so we can test that our
+  " "skip 'winfixbuf' window" logic works.
+  call win_gotoid(l:winfix_window)
+  call win_gotoid(l:quickfix_window)
+
+  cprevious
+  call assert_equal(l:first_window, win_getid())
+endfunc
+
+" Allow :cnfile but the 'nowinfixbuf' window is selected, instead
+func Test_cnfile()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first_window, l:winfix_window, l:quickfix_window] = s:make_quickfix_windows()
+
+  " The call to `:cnfile` succeeds but it selects the window with 'nowinfixbuf' instead
+  call s:set_quickfix_by_buffer(winbufnr(l:winfix_window))
+  cnext!
+
+  " Make sure the previous window has 'winfixbuf' so we can test that our
+  " "skip 'winfixbuf' window" logic works.
+  call win_gotoid(l:winfix_window)
+  call win_gotoid(l:quickfix_window)
+
+  cnfile
+  call assert_equal(l:first_window, win_getid())
+endfunc
+
+" Allow :cpfile but the 'nowinfixbuf' window is selected, instead
+func Test_cpfile()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first_window, l:winfix_window, l:quickfix_window] = s:make_quickfix_windows()
+
+  " The call to `:cpfile` succeeds but it selects the window with 'nowinfixbuf' instead
+  call s:set_quickfix_by_buffer(winbufnr(l:winfix_window))
+  cnext!
+
+  " Make sure the previous window has 'winfixbuf' so we can test that our
+  " "skip 'winfixbuf' window" logic works.
+  call win_gotoid(l:winfix_window)
+  call win_gotoid(l:quickfix_window)
+
+  cpfile
+  call assert_equal(l:first_window, win_getid())
+endfunc
+
+" Allow :crewind but the 'nowinfixbuf' window is selected, instead
+func Test_crewind()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first_window, l:winfix_window, l:quickfix_window] = s:make_quickfix_windows()
+
+  " The call to `:crewind` succeeds but it selects the window with 'nowinfixbuf' instead
+  call s:set_quickfix_by_buffer(winbufnr(l:winfix_window))
+  cnext!
+
+  " Make sure the previous window has 'winfixbuf' so we can test that our
+  " "skip 'winfixbuf' window" logic works.
+  call win_gotoid(l:winfix_window)
+  call win_gotoid(l:quickfix_window)
+
+  crewind
+  call assert_equal(l:first_window, win_getid())
+endfunc
+
+" Allow <C-w>f because it opens in a new split
+func Test_ctrl_w_f()
+  call s:reset_all_buffers()
+
+  enew
+  let l:file_name = tempname()
+  call writefile([], l:file_name)
+  let l:file_buffer = bufnr()
+
+  enew
+  file other
+  let l:other_buffer = bufnr()
+
+  set winfixbuf
+
+  call setline(1, l:file_name)
+  let l:current_windows = s:get_windows_count()
+  execute "normal \<C-w>f"
+
+  call assert_equal(l:current_windows + 1, s:get_windows_count())
+
+  call delete(l:file_name)
+endfunc
+
+" Fail :djump but :djump! is allowed
+func Test_djump()
+  call s:reset_all_buffers()
+
+  let l:include_file = tempname() . ".h"
+  call writefile(["min(1, 12);",
+        \ '#include "' . l:include_file . '"'
+        \ ],
+        \ "main.c")
+  call writefile(["#define min(X, Y)  ((X) < (Y) ? (X) : (Y))"], l:include_file)
+  edit main.c
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("djump 1 /min/", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  djump! 1 /min/
+  call assert_notequal(l:current, bufnr())
+
+  call delete("main.c")
+  call delete(l:include_file)
+endfunc
+
+" Fail :drop but :drop! is allowed
+func Test_drop()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("drop other", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  drop! other
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :edit but :edit! is allowed
+func Test_edit()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("edit other", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  edit! other
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :enew but :enew! is allowed
+func Test_enew()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("enew", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  enew!
+  call assert_notequal(l:other, bufnr())
+  call assert_notequal(3, bufnr())
+endfunc
+
+" Fail :ex but :ex! is allowed
+func Test_ex()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("ex other", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  ex! other
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :find but :find! is allowed
+func Test_find()
+  call s:reset_all_buffers()
+
+  let l:current = bufnr()
+  let l:file = tempname()
+  call writefile([], l:file)
+  let l:file = fnamemodify(l:file, ':p')  " In case it's Windows 8.3-style.
+  let l:directory = fnamemodify(l:file, ":p:h")
+  let l:name = fnamemodify(l:file, ":p:t")
+
+  let l:original_path = &path
+  execute "set path=" . l:directory
+
+  set winfixbuf
+
+  call assert_fails("execute 'find " . l:name . "'", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  execute "find! " . l:name
+  call assert_equal(l:file, expand("%:p"))
+
+  execute "set path=" . l:original_path
+  call delete(l:file)
+endfunc
+
+" Fail :first but :first! is allowed
+func Test_first()
+  call s:reset_all_buffers()
+
+  let [l:first, _] = s:make_args_list()
+  next!
+
+  call assert_fails("first", "E1513:")
+  call assert_notequal(l:first, bufnr())
+
+  first!
+  call assert_equal(l:first, bufnr())
+endfunc
+
+" Fail :grep but :grep! is allowed
+func Test_grep()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  edit first.unittest
+  call append(0, ["some-search-term"])
+  write
+  let l:first = bufnr()
+
+  edit current.unittest
+  call append(0, ["some-search-term"])
+  write
+  let l:current = bufnr()
+
+  edit! last.unittest
+  call append(0, ["some-search-term"])
+  write
+  let l:last = bufnr()
+
+  set winfixbuf
+
+  buffer! current.unittest
+
+  call assert_fails("silent! grep some-search-term *.unittest", "E1513:")
+  call assert_equal(l:current, bufnr())
+  execute "edit! " . l:first
+
+  silent! grep! some-search-term *.unittest
+  call assert_notequal(l:first, bufnr())
+
+  call delete("first.unittest")
+  call delete("current.unittest")
+  call delete("last.unittest")
+endfunc
+
+" Fail :ijump but :ijump! is allowed
+func Test_ijump()
+  call s:reset_all_buffers()
+
+  let l:include_file = tempname() . ".h"
+  call writefile([
+        \ '#include "' . l:include_file . '"'
+        \ ],
+        \ "main.c")
+  call writefile(["#define min(X, Y)  ((X) < (Y) ? (X) : (Y))"], l:include_file)
+  edit main.c
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  set define=^\\s*#\\s*define
+  set include=^\\s*#\\s*include
+  set path=.,/usr/include,,
+
+  call assert_fails("ijump /min/", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set nowinfixbuf
+
+  ijump! /min/
+  call assert_notequal(l:current, bufnr())
+
+  set define&
+  set include&
+  set path&
+  call delete("main.c")
+  call delete(l:include_file)
+endfunc
+
+" Fail :lNext but :lNext! is allowed
+func Test_lNext()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first, l:middle, _] = s:make_simple_location_list()
+  call assert_equal(1, getloclist(0, #{idx: 0}).idx)
+
+  lnext!
+  call assert_equal(2, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:middle, bufnr())
+
+  call assert_fails("lNext", "E1513:")
+  " Ensure the entry didn't change.
+  call assert_equal(2, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:middle, bufnr())
+
+  lnext!
+  call assert_equal(3, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:middle, bufnr())
+
+  lNext!
+  call assert_equal(2, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:middle, bufnr())
+
+  lNext!
+  call assert_equal(1, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:first, bufnr())
+endfunc
+
+" Fail :lNfile but :lNfile! is allowed
+func Test_lNfile()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first, l:current, _] = s:make_simple_location_list()
+  call assert_equal(1, getloclist(0, #{idx: 0}).idx)
+
+  lnext!
+  call assert_equal(2, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:current, bufnr())
+
+  call assert_fails("lNfile", "E1513:")
+  " Ensure the entry didn't change.
+  call assert_equal(2, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:current, bufnr())
+
+  lnext!
+  call assert_equal(3, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:current, bufnr())
+
+  lNfile!
+  call assert_equal(1, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:first, bufnr())
+endfunc
+
+" Allow :laddexpr because it doesn't change the current buffer
+func Test_laddexpr()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let l:file_path = tempname()
+  call writefile(["Error - bad-thing-found"], l:file_path)
+  execute "edit " . l:file_path
+  let l:file_buffer = bufnr()
+  let l:current = bufnr()
+
+  edit first.unittest
+  call append(0, ["some-search-term bad-thing-found"])
+
+  edit! other.unittest
+
+  set winfixbuf
+
+  execute "buffer! " . l:file_buffer
+
+  execute 'laddexpr expand("%") .. ":" .. line(".") .. ":" .. getline(".")'
+  call assert_equal(l:current, bufnr())
+
+  call delete(l:file_path)
+endfunc
+
+" Fail :last but :last! is allowed
+func Test_last()
+  call s:reset_all_buffers()
+
+  let [_, l:last] = s:make_args_list()
+  next!
+
+  call assert_fails("last", "E1513:")
+  call assert_notequal(l:last, bufnr())
+
+  last!
+  call assert_equal(l:last, bufnr())
+endfunc
+
+" Fail :lbuffer but :lbuffer! is allowed
+func Test_lbuffer()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let l:file_path = tempname()
+  call writefile(["first.unittest:1:Error - bad-thing-found"], l:file_path)
+  execute "edit " . l:file_path
+  let l:file_buffer = bufnr()
+  let l:current = bufnr()
+
+  edit first.unittest
+  call append(0, ["some-search-term bad-thing-found"])
+
+  edit! other.unittest
+
+  set winfixbuf
+
+  execute "buffer! " . l:file_buffer
+
+  call assert_fails("lbuffer " . l:file_buffer)
+  call assert_equal(l:current, bufnr())
+
+  execute "lbuffer! " . l:file_buffer
+  call assert_equal("first.unittest", expand("%:t"))
+
+  call delete(l:file_path)
+endfunc
+
+" Fail :ldo but :ldo! is allowed
+func Test_ldo()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first, l:middle, l:last] = s:make_simple_location_list()
+  lnext!
+
+  call assert_fails('execute "ldo buffer ' . l:first . '"', "E1513:")
+  call assert_equal(l:middle, bufnr())
+  execute "ldo! buffer " . l:first
+  call assert_notequal(l:last, bufnr())
+endfunc
+
+" Fail :lfdo but :lfdo! is allowed
+func Test_lexpr()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let l:file = tempname()
+  let l:entry = '["' . l:file . ':1:bar"]'
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  call assert_fails("lexpr " . l:entry)
+  call assert_equal(l:current, bufnr())
+
+  execute "lexpr! " . l:entry
+  call assert_equal(fnamemodify(l:file, ":t"), expand("%:t"))
+endfunc
+
+" Fail :lfdo but :lfdo! is allowed
+func Test_lfdo()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first, l:middle, l:last] = s:make_simple_location_list()
+  lnext!
+
+  call assert_fails('execute "lfdo buffer ' . l:first . '"', "E1513:")
+  call assert_equal(l:middle, bufnr())
+  execute "lfdo! buffer " . l:first
+  call assert_notequal(l:last, bufnr())
+endfunc
+
+" Fail :lfile but :lfile! is allowed
+func Test_lfile()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  edit first.unittest
+  call append(0, ["some-search-term bad-thing-found"])
+  write
+  let l:first = bufnr()
+
+  edit! second.unittest
+  call append(0, ["some-search-term"])
+  write
+
+  let l:file = tempname()
+  call writefile(["first.unittest:1:Error - bad-thing-found was detected"], l:file)
+
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  call assert_fails(":lfile " . l:file)
+  call assert_equal(l:current, bufnr())
+
+  execute ":lfile! " . l:file
+  call assert_equal(l:first, bufnr())
+
+  call delete(l:file)
+  call delete("first.unittest")
+  call delete("second.unittest")
+endfunc
+
+" Fail :ll but :ll! is allowed
+func Test_ll()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first, l:middle, l:last] = s:make_simple_location_list()
+  lopen
+  lfirst!
+  execute "normal \<C-w>j"
+  normal j
+
+  call assert_fails(".ll", "E1513:")
+  execute "normal \<C-w>k"
+  call assert_equal(l:first, bufnr())
+  execute "normal \<C-w>j"
+  .ll!
+  execute "normal \<C-w>k"
+  call assert_equal(l:middle, bufnr())
+endfunc
+
+" Fail :llast but :llast! is allowed
+func Test_llast()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first, _, l:last] = s:make_simple_location_list()
+  lfirst!
+
+  call assert_fails("llast", "E1513:")
+  call assert_equal(l:first, bufnr())
+
+  llast!
+  call assert_equal(l:last, bufnr())
+endfunc
+
+" Fail :lnext but :lnext! is allowed
+func Test_lnext()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first, l:middle, l:last] = s:make_simple_location_list()
+  ll!
+
+  call assert_fails("lnext", "E1513:")
+  call assert_equal(l:first, bufnr())
+
+  lnext!
+  call assert_equal(l:middle, bufnr())
+endfunc
+
+" Fail :lnfile but :lnfile! is allowed
+func Test_lnfile()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [_, l:current, l:last] = s:make_simple_location_list()
+  call assert_equal(1, getloclist(0, #{idx: 0}).idx)
+
+  lnext!
+  call assert_equal(2, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:current, bufnr())
+
+  call assert_fails("lnfile", "E1513:")
+  " Ensure the entry didn't change.
+  call assert_equal(2, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:current, bufnr())
+
+  lnfile!
+  call assert_equal(4, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:last, bufnr())
+endfunc
+
+" Fail :lpfile but :lpfile! is allowed
+func Test_lpfile()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first, l:current, _] = s:make_simple_location_list()
+  lnext!
+
+  call assert_fails("lpfile", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  lnext!  " Reset for the next test call
+
+  lpfile!
+  call assert_equal(l:first, bufnr())
+endfunc
+
+" Fail :lprevious but :lprevious! is allowed
+func Test_lprevious()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first, l:middle, _] = s:make_simple_location_list()
+  call assert_equal(1, getloclist(0, #{idx: 0}).idx)
+
+  lnext!
+  call assert_equal(2, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:middle, bufnr())
+
+  call assert_fails("lprevious", "E1513:")
+  " Ensure the entry didn't change.
+  call assert_equal(2, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:middle, bufnr())
+
+  lprevious!
+  call assert_equal(1, getloclist(0, #{idx: 0}).idx)
+  call assert_equal(l:first, bufnr())
+endfunc
+
+" Fail :lrewind but :lrewind! is allowed
+func Test_lrewind()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  let [l:first, l:middle, _] = s:make_simple_location_list()
+  lnext!
+
+  call assert_fails("lrewind", "E1513:")
+  call assert_equal(l:middle, bufnr())
+
+  lrewind!
+  call assert_equal(l:first, bufnr())
+endfunc
+
+" Fail :ltag but :ltag! is allowed
+func Test_ltag()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+  execute "normal \<C-]>"
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("ltag one", "E1513:")
+
+  ltag! one
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Fail vim.command if we try to change buffers while 'winfixbuf' is set
+func Test_lua_command()
+  CheckFeature lua
+  call s:reset_all_buffers()
+
+  enew
+  file first
+  let l:previous = bufnr()
+
+  enew
+  file second
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  call assert_fails('lua vim.command("buffer " .. ' . l:previous . ')')
+  call assert_equal(l:current, bufnr())
+
+  execute 'lua vim.command("buffer! " .. ' . l:previous . ')'
+  call assert_equal(l:previous, bufnr())
+endfunc
+
+" Fail :lvimgrep but :lvimgrep! is allowed
+func Test_lvimgrep()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  edit first.unittest
+  call append(0, ["some-search-term"])
+  write
+
+  edit winfix.unittest
+  call append(0, ["some-search-term"])
+  write
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  edit! last.unittest
+  call append(0, ["some-search-term"])
+  write
+  let l:last = bufnr()
+
+  buffer! winfix.unittest
+
+  call assert_fails("lvimgrep /some-search-term/ *.unittest", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  lvimgrep! /some-search-term/ *.unittest
+  call assert_notequal(l:current, bufnr())
+
+  call delete("first.unittest")
+  call delete("winfix.unittest")
+  call delete("last.unittest")
+endfunc
+
+" Fail :lvimgrepadd but :lvimgrepadd! is allowed
+func Test_lvimgrepadd()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  edit first.unittest
+  call append(0, ["some-search-term"])
+  write
+
+  edit winfix.unittest
+  call append(0, ["some-search-term"])
+  write
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  edit! last.unittest
+  call append(0, ["some-search-term"])
+  write
+  let l:last = bufnr()
+
+  buffer! winfix.unittest
+
+  call assert_fails("lvimgrepadd /some-search-term/ *.unittest")
+  call assert_equal(l:current, bufnr())
+
+  lvimgrepadd! /some-search-term/ *.unittest
+  call assert_notequal(l:current, bufnr())
+
+  call delete("first.unittest")
+  call delete("winfix.unittest")
+  call delete("last.unittest")
+endfunc
+
+" Don't allow global marks to change the current 'winfixbuf' window
+func Test_marks_mappings_fail()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+  execute "buffer! " . l:other
+  normal mA
+  execute "buffer! " . l:current
+  normal mB
+
+  call assert_fails("normal `A", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  call assert_fails("normal 'A", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set nowinfixbuf
+
+  normal `A
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Allow global marks in a 'winfixbuf' window if the jump is the same buffer
+func Test_marks_mappings_pass_intra_move()
+  call s:reset_all_buffers()
+
+  let l:current = bufnr()
+  call append(0, ["some line", "another line"])
+  normal mA
+  normal j
+  normal mB
+
+  set winfixbuf
+
+  normal `A
+  call assert_equal(l:current, bufnr())
+endfunc
+
+" Fail :next but :next! is allowed
+func Test_next()
+  call s:reset_all_buffers()
+
+  let [l:first, _] = s:make_args_list()
+  first!
+
+  call assert_fails("next", "E1513:")
+  call assert_equal(l:first, bufnr())
+
+  next!
+  call assert_notequal(l:first, bufnr())
+endfunc
+
+" Ensure :mksession saves 'winfixbuf' details
+func Test_mksession()
+  CheckFeature mksession
+  call s:reset_all_buffers()
+
+  set sessionoptions+=options
+  set winfixbuf
+
+  mksession test_winfixbuf_Test_mksession.vim
+
+  call s:reset_all_buffers()
+  let l:winfixbuf = &winfixbuf
+  call assert_equal(0, l:winfixbuf)
+
+  source test_winfixbuf_Test_mksession.vim
+
+  let l:winfixbuf = &winfixbuf
+  call assert_equal(1, l:winfixbuf)
+
+  set sessionoptions&
+  call delete("test_winfixbuf_Test_mksession.vim")
+endfunc
+
+" Allow :next if the next index is the same as the current buffer
+func Test_next_same_buffer()
+  call s:reset_all_buffers()
+
+  enew
+  file foo
+  enew
+  file bar
+  enew
+  file fizz
+  enew
+  file buzz
+  args foo foo bar fizz buzz
+
+  edit foo
+  set winfixbuf
+  let l:current = bufnr()
+
+  " Allow :next because the args list is `[foo] foo bar fizz buzz
+  next
+  call assert_equal(l:current, bufnr())
+
+  " Fail :next because the args list is `foo [foo] bar fizz buzz
+  " and the next buffer would be bar, which is a different buffer
+  call assert_fails("next", "E1513:")
+  call assert_equal(l:current, bufnr())
+endfunc
+
+" Fail to jump to a tag with g<C-]> if 'winfixbuf' is enabled
+func Test_normal_g_ctrl_square_bracket_right()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("normal g\<C-]>", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Fail to jump to a tag with g<RightMouse> if 'winfixbuf' is enabled
+func Test_normal_g_rightmouse()
+  call s:reset_all_buffers()
+  set mouse=n
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+  execute "normal \<C-]>"
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("normal g\<RightMouse>", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set tags&
+  set mouse&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Fail to jump to a tag with g] if 'winfixbuf' is enabled
+func Test_normal_g_square_bracket_right()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("normal g]", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Fail to jump to a tag with <C-RightMouse> if 'winfixbuf' is enabled
+func Test_normal_ctrl_rightmouse()
+  call s:reset_all_buffers()
+  set mouse=n
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+  execute "normal \<C-]>"
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("normal \<C-RightMouse>", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set tags&
+  set mouse&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Fail to jump to a tag with <C-t> if 'winfixbuf' is enabled
+func Test_normal_ctrl_t()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+  execute "normal \<C-]>"
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("normal \<C-t>", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Disallow <C-^> in 'winfixbuf' windows
+func Test_normal_ctrl_hat()
+  call s:reset_all_buffers()
+  clearjumps
+
+  enew
+  file first
+  let l:first = bufnr()
+
+  enew
+  file current
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  call assert_fails("normal \<C-^>", "E1513:")
+  call assert_equal(l:current, bufnr())
+endfunc
+
+" Allow <C-i> in 'winfixbuf' windows if the movement stays within the buffer
+func Test_normal_ctrl_i_pass()
+  call s:reset_all_buffers()
+  clearjumps
+
+  enew
+  file first
+  let l:first = bufnr()
+
+  enew!
+  file current
+  let l:current = bufnr()
+  " Add some lines so we can populate a jumplist"
+  call append(0, ["some line", "another line"])
+  " Add an entry to the jump list
+  " Go up another line
+  normal m`
+  normal k
+  execute "normal \<C-o>"
+
+  set winfixbuf
+
+  let l:line = getcurpos()[1]
+  execute "normal 1\<C-i>"
+  call assert_notequal(l:line, getcurpos()[1])
+endfunc
+
+" Disallow <C-o> in 'winfixbuf' windows if it would cause the buffer to switch
+func Test_normal_ctrl_o_fail()
+  call s:reset_all_buffers()
+  clearjumps
+
+  enew
+  file first
+  let l:first = bufnr()
+
+  enew
+  file current
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  call assert_fails("normal \<C-o>", "E1513:")
+  call assert_equal(l:current, bufnr())
+endfunc
+
+" Allow <C-o> in 'winfixbuf' windows if the movement stays within the buffer
+func Test_normal_ctrl_o_pass()
+  call s:reset_all_buffers()
+  clearjumps
+
+  enew
+  file first
+  let l:first = bufnr()
+
+  enew!
+  file current
+  let l:current = bufnr()
+  " Add some lines so we can populate a jumplist
+  call append(0, ["some line", "another line"])
+  " Add an entry to the jump list
+  " Go up another line
+  normal m`
+  normal k
+
+  set winfixbuf
+
+  execute "normal \<C-o>"
+  call assert_equal(l:current, bufnr())
+endfunc
+
+" Fail to jump to a tag with <C-]> if 'winfixbuf' is enabled
+func Test_normal_ctrl_square_bracket_right()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("normal \<C-]>", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Allow <C-w><C-]> with 'winfixbuf' enabled because it runs in a new, split window
+func Test_normal_ctrl_w_ctrl_square_bracket_right()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+
+  set winfixbuf
+
+  let l:current_windows = s:get_windows_count()
+  execute "normal \<C-w>\<C-]>"
+  call assert_equal(l:current_windows + 1, s:get_windows_count())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Allow <C-w>g<C-]> with 'winfixbuf' enabled because it runs in a new, split window
+func Test_normal_ctrl_w_g_ctrl_square_bracket_right()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+
+  set winfixbuf
+
+  let l:current_windows = s:get_windows_count()
+  execute "normal \<C-w>g\<C-]>"
+  call assert_equal(l:current_windows + 1, s:get_windows_count())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Fail to jump to a tag with <C-]> if 'winfixbuf' is enabled
+func Test_normal_gt()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one", "two", "three"], "Xother")
+  edit Xother
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("normal \<C-]>", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Prevent gF from switching a 'winfixbuf' window's buffer
+func Test_normal_gF()
+  call s:reset_all_buffers()
+
+  let l:file = tempname()
+  call append(0, [l:file])
+  call writefile([], l:file)
+  " Place the cursor onto the line that has `l:file`
+  normal gg
+  " Prevent Vim from erroring with "No write since last change @ command
+  " line" when we try to call gF, later.
+  set hidden
+
+  set winfixbuf
+
+  let l:buffer = bufnr()
+
+  call assert_fails("normal gF", "E1513:")
+  call assert_equal(l:buffer, bufnr())
+
+  set nowinfixbuf
+
+  normal gF
+  call assert_notequal(l:buffer, bufnr())
+
+  call delete(l:file)
+endfunc
+
+" Prevent gf from switching a 'winfixbuf' window's buffer
+func Test_normal_gf()
+  call s:reset_all_buffers()
+
+  let l:file = tempname()
+  call append(0, [l:file])
+  call writefile([], l:file)
+  " Place the cursor onto the line that has `l:file`
+  normal gg
+  " Prevent Vim from erroring with "No write since last change @ command
+  " line" when we try to call gf, later.
+  set hidden
+
+  set winfixbuf
+
+  let l:buffer = bufnr()
+
+  call assert_fails("normal gf", "E1513:")
+  call assert_equal(l:buffer, bufnr())
+
+  set nowinfixbuf
+
+  normal gf
+  call assert_notequal(l:buffer, bufnr())
+
+  call delete(l:file)
+endfunc
+
+" Fail "goto file under the cursor" (using [f, which is the same as `:normal gf`)
+func Test_normal_square_bracket_left_f()
+  call s:reset_all_buffers()
+
+  let l:file = tempname()
+  call append(0, [l:file])
+  call writefile([], l:file)
+  " Place the cursor onto the line that has `l:file`
+  normal gg
+  " Prevent Vim from erroring with "No write since last change @ command
+  " line" when we try to call gf, later.
+  set hidden
+
+  set winfixbuf
+
+  let l:buffer = bufnr()
+
+  call assert_fails("normal [f", "E1513:")
+  call assert_equal(l:buffer, bufnr())
+
+  set nowinfixbuf
+
+  normal [f
+  call assert_notequal(l:buffer, bufnr())
+
+  call delete(l:file)
+endfunc
+
+" Fail to go to a C macro with [<C-d> if 'winfixbuf' is enabled
+func Test_normal_square_bracket_left_ctrl_d()
+  call s:reset_all_buffers()
+
+  let l:include_file = tempname() . ".h"
+  call writefile(["min(1, 12);",
+        \ '#include "' . l:include_file . '"'
+        \ ],
+        \ "main.c")
+  call writefile(["#define min(X, Y)  ((X) < (Y) ? (X) : (Y))"], l:include_file)
+  edit main.c
+  normal ]\<C-d>
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("normal [\<C-d>", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set nowinfixbuf
+
+  execute "normal [\<C-d>"
+  call assert_notequal(l:current, bufnr())
+
+  call delete("main.c")
+  call delete(l:include_file)
+endfunc
+
+" Fail to go to a C macro with ]<C-d> if 'winfixbuf' is enabled
+func Test_normal_square_bracket_right_ctrl_d()
+  call s:reset_all_buffers()
+
+  let l:include_file = tempname() . ".h"
+  call writefile(["min(1, 12);",
+        \ '#include "' . l:include_file . '"'
+        \ ],
+        \ "main.c")
+  call writefile(["#define min(X, Y)  ((X) < (Y) ? (X) : (Y))"], l:include_file)
+  edit main.c
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("normal ]\<C-d>", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set nowinfixbuf
+
+  execute "normal ]\<C-d>"
+  call assert_notequal(l:current, bufnr())
+
+  call delete("main.c")
+  call delete(l:include_file)
+endfunc
+
+" Fail to go to a C macro with [<C-i> if 'winfixbuf' is enabled
+func Test_normal_square_bracket_left_ctrl_i()
+  call s:reset_all_buffers()
+
+  let l:include_file = tempname() . ".h"
+  call writefile(['#include "' . l:include_file . '"',
+        \ "min(1, 12);",
+        \ ],
+        \ "main.c")
+  call writefile(["#define min(X, Y)  ((X) < (Y) ? (X) : (Y))"], l:include_file)
+  edit main.c
+  " Move to the line with `min(1, 12);` on it"
+  normal j
+
+  set define=^\\s*#\\s*define
+  set include=^\\s*#\\s*include
+  set path=.,/usr/include,,
+
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  call assert_fails("normal [\<C-i>", "E1513:")
+
+  set nowinfixbuf
+
+  execute "normal [\<C-i>"
+  call assert_notequal(l:current, bufnr())
+
+  set define&
+  set include&
+  set path&
+  call delete("main.c")
+  call delete(l:include_file)
+endfunc
+
+" Fail to go to a C macro with ]<C-i> if 'winfixbuf' is enabled
+func Test_normal_square_bracket_right_ctrl_i()
+  call s:reset_all_buffers()
+
+  let l:include_file = tempname() . ".h"
+  call writefile(["min(1, 12);",
+        \ '#include "' . l:include_file . '"'
+        \ ],
+        \ "main.c")
+  call writefile(["#define min(X, Y)  ((X) < (Y) ? (X) : (Y))"], l:include_file)
+  edit main.c
+
+  set winfixbuf
+
+  set define=^\\s*#\\s*define
+  set include=^\\s*#\\s*include
+  set path=.,/usr/include,,
+
+  let l:current = bufnr()
+
+  call assert_fails("normal ]\<C-i>", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set nowinfixbuf
+
+  execute "normal ]\<C-i>"
+  call assert_notequal(l:current, bufnr())
+
+  set define&
+  set include&
+  set path&
+  call delete("main.c")
+  call delete(l:include_file)
+endfunc
+
+" Fail "goto file under the cursor" (using ]f, which is the same as `:normal gf`)
+func Test_normal_square_bracket_right_f()
+  call s:reset_all_buffers()
+
+  let l:file = tempname()
+  call append(0, [l:file])
+  call writefile([], l:file)
+  " Place the cursor onto the line that has `l:file`
+  normal gg
+  " Prevent Vim from erroring with "No write since last change @ command
+  " line" when we try to call gf, later.
+  set hidden
+
+  set winfixbuf
+
+  let l:buffer = bufnr()
+
+  call assert_fails("normal ]f", "E1513:")
+  call assert_equal(l:buffer, bufnr())
+
+  set nowinfixbuf
+
+  normal ]f
+  call assert_notequal(l:buffer, bufnr())
+
+  call delete(l:file)
+endfunc
+
+" Fail to jump to a tag with v<C-]> if 'winfixbuf' is enabled
+func Test_normal_v_ctrl_square_bracket_right()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("normal v\<C-]>", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Fail to jump to a tag with vg<C-]> if 'winfixbuf' is enabled
+func Test_normal_v_g_ctrl_square_bracket_right()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("normal vg\<C-]>", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Allow :pedit because, unlike :edit, it uses a separate window
+func Test_pedit()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+
+  pedit other
+
+  execute "normal \<C-w>w"
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :pop but :pop! is allowed
+func Test_pop()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "thesame\tXfile\t1;\"\td\tfile:",
+        \ "thesame\tXfile\t2;\"\td\tfile:",
+        \ "thesame\tXfile\t3;\"\td\tfile:",
+        \ ],
+        \ "Xtags")
+  call writefile(["thesame one", "thesame two", "thesame three"], "Xfile")
+  call writefile(["thesame one"], "Xother")
+  edit Xother
+
+  tag thesame
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("pop", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  pop!
+  call assert_notequal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Fail :previous but :previous! is allowed
+func Test_previous()
+  call s:reset_all_buffers()
+
+  let [l:first, _] = s:make_args_list()
+  next!
+
+  call assert_fails("previous", "E1513:")
+  call assert_notequal(l:first, bufnr())
+
+  previous!
+  call assert_equal(l:first, bufnr())
+endfunc
+
+" Fail pyxdo if it changes a window with 'winfixbuf' is set
+func Test_pythonx_pyxdo()
+  CheckFeature pythonx
+  call s:reset_all_buffers()
+
+  enew
+  file first
+  let g:_previous_buffer = bufnr()
+
+  enew
+  file second
+
+  set winfixbuf
+
+  pythonx << EOF
+import vim
+
+def test_winfixbuf_Test_pythonx_pyxdo_set_buffer():
+    buffer = vim.vars['_previous_buffer']
+    vim.current.buffer = vim.buffers[buffer]
+EOF
+
+  try
+    pyxdo test_winfixbuf_Test_pythonx_pyxdo_set_buffer()
+  catch /Vim\%((\a\+)\)\=:E1513:/
+    let l:caught = 1
+  endtry
+
+  call assert_equal(1, l:caught)
+
+  unlet g:_previous_buffer
+endfunc
+
+" Fail pyxfile if it changes a window with 'winfixbuf' is set
+func Test_pythonx_pyxfile()
+  CheckFeature pythonx
+  call s:reset_all_buffers()
+
+  enew
+  file first
+  let g:_previous_buffer = bufnr()
+
+  enew
+  file second
+
+  set winfixbuf
+
+  call writefile(["import vim",
+        \ "buffer = vim.vars['_previous_buffer']",
+        \ "vim.current.buffer = vim.buffers[buffer]",
+        \ ],
+        \ "file.py")
+
+  try
+    pyxfile file.py
+  catch /Vim\%((\a\+)\)\=:E1513:/
+    let l:caught = 1
+  endtry
+
+  call assert_equal(1, l:caught)
+
+  call delete("file.py")
+  unlet g:_previous_buffer
+endfunc
+
+" Fail vim.current.buffer if 'winfixbuf' is set
+func Test_pythonx_vim_current_buffer()
+  CheckFeature pythonx
+  call s:reset_all_buffers()
+
+  enew
+  file first
+  let g:_previous_buffer = bufnr()
+
+  enew
+  file second
+
+  let l:caught = 0
+
+  set winfixbuf
+
+  try
+    pythonx << EOF
+import vim
+
+buffer = vim.vars["_previous_buffer"]
+vim.current.buffer = vim.buffers[buffer]
+EOF
+  catch /Vim\%((\a\+)\)\=:E1513:/
+    let l:caught = 1
+  endtry
+
+  call assert_equal(1, l:caught)
+  unlet g:_previous_buffer
+endfunc
+
+" Ensure remapping to a disabled action still triggers failures
+func Test_remap_key_fail()
+  call s:reset_all_buffers()
+
+  enew
+  file first
+  let l:first = bufnr()
+
+  enew
+  file current
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  nnoremap g <C-^>
+
+  call assert_fails("normal g", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  nunmap g
+endfunc
+
+" Ensure remapping a disabled key to something valid does trigger any failures
+func Test_remap_key_pass()
+  call s:reset_all_buffers()
+
+  enew
+  file first
+  let l:first = bufnr()
+
+  enew
+  file current
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  call assert_fails("normal \<C-^>", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  " Disallow <C-^> by default but allow it if the command does something else
+  nnoremap <C-^> :echo "hello!"
+
+  execute "normal \<C-^>"
+  call assert_equal(l:current, bufnr())
+
+  nunmap <C-^>
+endfunc
+
+" Fail :rewind but :rewind! is allowed
+func Test_rewind()
+  call s:reset_all_buffers()
+
+  let [l:first, _] = s:make_args_list()
+  next!
+
+  call assert_fails("rewind", "E1513:")
+  call assert_notequal(l:first, bufnr())
+
+  rewind!
+  call assert_equal(l:first, bufnr())
+endfunc
+
+" Allow :sblast because it opens the buffer in a new, split window
+func Test_sblast()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs(1)
+  bfirst!
+  let l:current = bufnr()
+
+  sblast
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :sbprevious but :sbprevious! is allowed
+func Test_sbprevious()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  sbprevious
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Make sure 'winfixbuf' can be set using 'winfixbuf' or 'wfb'
+func Test_short_option()
+  call s:reset_all_buffers()
+
+  call s:make_buffer_pairs()
+
+  set winfixbuf
+  call assert_fails("edit something_else", "E1513")
+
+  set nowinfixbuf
+  set wfb
+  call assert_fails("edit another_place", "E1513")
+
+  set nowfb
+  edit last_place
+endfunc
+
+" Allow :snext because it makes a new window
+func Test_snext()
+  call s:reset_all_buffers()
+
+  let [l:first, _] = s:make_args_list()
+  first!
+
+  let l:current_window = win_getid()
+
+  snext
+  call assert_notequal(l:current_window, win_getid())
+  call assert_notequal(l:first, bufnr())
+endfunc
+
+" Ensure the first has 'winfixbuf' and a new split window is 'nowinfixbuf'
+func Test_split_window()
+  call s:reset_all_buffers()
+
+  split
+  execute "normal \<C-w>j"
+
+  set winfixbuf
+
+  let l:winfix_window_1 = win_getid()
+  vsplit
+  let l:winfix_window_2 = win_getid()
+
+  call assert_equal(1, getwinvar(l:winfix_window_1, "&winfixbuf"))
+  call assert_equal(0, getwinvar(l:winfix_window_2, "&winfixbuf"))
+endfunc
+
+" Fail :tNext but :tNext! is allowed
+func Test_tNext()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "thesame\tXfile\t1;\"\td\tfile:",
+        \ "thesame\tXfile\t2;\"\td\tfile:",
+        \ "thesame\tXfile\t3;\"\td\tfile:",
+        \ ],
+        \ "Xtags")
+  call writefile(["thesame one", "thesame two", "thesame three"], "Xfile")
+  call writefile(["thesame one"], "Xother")
+  edit Xother
+
+  tag thesame
+  execute "normal \<C-^>"
+  tnext!
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("tNext", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  tNext!
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Call :tabdo and choose the next available 'nowinfixbuf' window.
+func Test_tabdo_choose_available_window()
+  call s:reset_all_buffers()
+
+  let [l:first, _] = s:make_args_list()
+
+  " Make a split window that is 'nowinfixbuf' but make it the second-to-last
+  " window so that :tabdo will first try the 'winfixbuf' window, pass over it,
+  " and prefer the other 'nowinfixbuf' window, instead.
+  "
+  " +-------------------+
+  " |   'nowinfixbuf'   |
+  " +-------------------+
+  " |    'winfixbuf'    |  <-- Cursor is here
+  " +-------------------+
+  split
+  let l:nowinfixbuf_window = win_getid()
+  " Move to the 'winfixbuf' window now
+  execute "normal \<C-w>j"
+  let l:winfixbuf_window = win_getid()
+
+  let l:expected_windows = s:get_windows_count()
+  tabdo echo ''
+  call assert_equal(l:nowinfixbuf_window, win_getid())
+  call assert_equal(l:first, bufnr())
+  call assert_equal(l:expected_windows, s:get_windows_count())
+endfunc
+
+" Call :tabdo and create a new split window if all available windows are 'winfixbuf'.
+func Test_tabdo_make_new_window()
+  call s:reset_all_buffers()
+
+  let [l:first, _] = s:make_buffers_list()
+  execute "buffer! " . l:first
+
+  let l:current = win_getid()
+  let l:current_windows = s:get_windows_count()
+
+  tabdo echo ''
+  call assert_notequal(l:current, win_getid())
+  call assert_equal(l:first, bufnr())
+  execute "normal \<C-w>j"
+  call assert_equal(l:first, bufnr())
+  call assert_equal(l:current_windows + 1, s:get_windows_count())
+endfunc
+
+" Fail :tag but :tag! is allowed
+func Test_tag()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("tag one", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  tag! one
+  call assert_notequal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+
+" Fail :tfirst but :tfirst! is allowed
+func Test_tfirst()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("tfirst", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  tfirst!
+  call assert_notequal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Fail :tjump but :tjump! is allowed
+func Test_tjump()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  call writefile(["one"], "Xother")
+  edit Xother
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("tjump one", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  tjump! one
+  call assert_notequal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Fail :tlast but :tlast! is allowed
+func Test_tlast()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "one\tXfile\t1",
+        \ "three\tXfile\t3",
+        \ "two\tXfile\t2"],
+        \ "Xtags")
+  call writefile(["one", "two", "three"], "Xfile")
+  edit Xfile
+  tjump one
+  edit Xfile
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("tlast", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  tlast!
+  call assert_equal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+endfunc
+
+" Fail :tnext but :tnext! is allowed
+func Test_tnext()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "thesame\tXfile\t1;\"\td\tfile:",
+        \ "thesame\tXfile\t2;\"\td\tfile:",
+        \ "thesame\tXfile\t3;\"\td\tfile:",
+        \ ],
+        \ "Xtags")
+  call writefile(["thesame one", "thesame two", "thesame three"], "Xfile")
+  call writefile(["thesame one"], "Xother")
+  edit Xother
+
+  tag thesame
+  execute "normal \<C-^>"
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("tnext", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  tnext!
+  call assert_notequal(l:current, bufnr())
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Fail :tprevious but :tprevious! is allowed
+func Test_tprevious()
+  call s:reset_all_buffers()
+
+  set tags=Xtags
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "thesame\tXfile\t1;\"\td\tfile:",
+        \ "thesame\tXfile\t2;\"\td\tfile:",
+        \ "thesame\tXfile\t3;\"\td\tfile:",
+        \ ],
+        \ "Xtags")
+  call writefile(["thesame one", "thesame two", "thesame three"], "Xfile")
+  call writefile(["thesame one"], "Xother")
+  edit Xother
+
+  tag thesame
+  execute "normal \<C-^>"
+  tnext!
+
+  set winfixbuf
+
+  let l:current = bufnr()
+
+  call assert_fails("tprevious", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  tprevious!
+
+  set tags&
+  call delete("Xtags")
+  call delete("Xfile")
+  call delete("Xother")
+endfunc
+
+" Fail :view but :view! is allowed
+func Test_view()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("view other", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  view! other
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :visual but :visual! is allowed
+func Test_visual()
+  call s:reset_all_buffers()
+
+  let l:other = s:make_buffer_pairs()
+  let l:current = bufnr()
+
+  call assert_fails("visual other", "E1513:")
+  call assert_equal(l:current, bufnr())
+
+  visual! other
+  call assert_equal(l:other, bufnr())
+endfunc
+
+" Fail :vimgrep but :vimgrep! is allowed
+func Test_vimgrep()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  edit first.unittest
+  call append(0, ["some-search-term"])
+  write
+
+  edit winfix.unittest
+  call append(0, ["some-search-term"])
+  write
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  edit! last.unittest
+  call append(0, ["some-search-term"])
+  write
+  let l:last = bufnr()
+
+  buffer! winfix.unittest
+
+  call assert_fails("vimgrep /some-search-term/ *.unittest")
+  call assert_equal(l:current, bufnr())
+
+  " Don't error and also do swap to the first match because ! was included
+  vimgrep! /some-search-term/ *.unittest
+  call assert_notequal(l:current, bufnr())
+
+  call delete("first.unittest")
+  call delete("winfix.unittest")
+  call delete("last.unittest")
+endfunc
+
+" Fail :vimgrepadd but ::vimgrepadd! is allowed
+func Test_vimgrepadd()
+  CheckFeature quickfix
+  call s:reset_all_buffers()
+
+  edit first.unittest
+  call append(0, ["some-search-term"])
+  write
+
+  edit winfix.unittest
+  call append(0, ["some-search-term"])
+  write
+  let l:current = bufnr()
+
+  set winfixbuf
+
+  edit! last.unittest
+  call append(0, ["some-search-term"])
+  write
+  let l:last = bufnr()
+
+  buffer! winfix.unittest
+
+  call assert_fails("vimgrepadd /some-search-term/ *.unittest")
+  call assert_equal(l:current, bufnr())
+
+  vimgrepadd! /some-search-term/ *.unittest
+  call assert_notequal(l:current, bufnr())
+  call delete("first.unittest")
+  call delete("winfix.unittest")
+  call delete("last.unittest")
+endfunc
+
+" Fail :wNext but :wNext! is allowed
+func Test_wNext()
+  call s:reset_all_buffers()
+
+  let [l:first, _] = s:make_args_list()
+  next!
+
+  call assert_fails("wNext", "E1513:")
+  call assert_notequal(l:first, bufnr())
+
+  wNext!
+  call assert_equal(l:first, bufnr())
+
+  call delete("first")
+  call delete("middle")
+  call delete("last")
+endfunc
+
+" Allow :windo unless `:windo foo` would change a 'winfixbuf' window's buffer
+func Test_windo()
+  call s:reset_all_buffers()
+
+  let l:current_window = win_getid()
+  let l:current_buffer = bufnr()
+  split
+  enew
+  file some_other_buffer
+
+  set winfixbuf
+
+  let l:current = win_getid()
+
+  windo echo ''
+  call assert_equal(l:current_window, win_getid())
+
+  call assert_fails('execute "windo buffer ' . l:current_buffer . '"', "E1513:")
+  call assert_equal(l:current_window, win_getid())
+
+  execute "windo buffer! " . l:current_buffer
+  call assert_equal(l:current_window, win_getid())
+endfunc
+
+" Fail :wnext but :wnext! is allowed
+func Test_wnext()
+  call s:reset_all_buffers()
+
+  let [_, l:last] = s:make_args_list()
+  next!
+
+  call assert_fails("wnext", "E1513:")
+  call assert_notequal(l:last, bufnr())
+
+  wnext!
+  call assert_equal(l:last, bufnr())
+
+  call delete("first")
+  call delete("middle")
+  call delete("last")
+endfunc
+
+" Fail :wprevious but :wprevious! is allowed
+func Test_wprevious()
+  call s:reset_all_buffers()
+
+  let [l:first, _] = s:make_args_list()
+  next!
+
+  call assert_fails("wprevious", "E1513:")
+  call assert_notequal(l:first, bufnr())
+
+  wprevious!
+  call assert_equal(l:first, bufnr())
+
+  call delete("first")
+  call delete("middle")
+  call delete("last")
+endfunc
+
+func Test_quickfix_switchbuf_invalid_prevwin()
+  call s:reset_all_buffers()
+
+  call s:make_simple_quickfix()
+  call assert_equal(1, getqflist(#{idx: 0}).idx)
+
+  set switchbuf=uselast
+  split
+  copen
+  execute winnr('#') 'quit'
+  call assert_equal(2, winnr('$'))
+
+  cnext  " Would've triggered a null pointer member access
+  call assert_equal(2, getqflist(#{idx: 0}).idx)
+
+  set switchbuf&
+endfunc
+
+func Test_listdo_goto_prevwin()
+  call s:reset_all_buffers()
+  call s:make_buffers_list()
+
+  new
+  call assert_equal(0, &winfixbuf)
+  wincmd p
+  call assert_equal(1, &winfixbuf)
+  call assert_notequal(bufnr(), bufnr('#'))
+
+  augroup ListDoGotoPrevwin
+    au!
+    au BufLeave * let s:triggered = 1
+          \| call assert_equal(bufnr(), winbufnr(winnr()))
+  augroup END
+  " Should correctly switch to the window without 'winfixbuf', and curbuf should
+  " be consistent with curwin->w_buffer for autocommands.
+  bufdo "
+  call assert_equal(0, &winfixbuf)
+  call assert_equal(1, s:triggered)
+  unlet! s:triggered
+  au! ListDoGotoPrevwin
+
+  set winfixbuf
+  wincmd p
+  call assert_equal(2, winnr('$'))
+  " Both curwin and prevwin have 'winfixbuf' set, so should split a new window
+  " without it set.
+  bufdo "
+  call assert_equal(0, &winfixbuf)
+  call assert_equal(3, winnr('$'))
+
+  quit
+  call assert_equal(2, winnr('$'))
+  call assert_equal(1, &winfixbuf)
+  augroup ListDoGotoPrevwin
+    au!
+    au WinEnter * ++once set winfixbuf
+  augroup END
+  " Same as before, but naughty autocommands set 'winfixbuf' for the new window.
+  " :bufdo should give up in this case.
+  call assert_fails('bufdo "', 'E1513:')
+
+  au! ListDoGotoPrevwin
+  augroup! ListDoGotoPrevwin
+endfunc
+
+func Test_quickfix_changed_split_failed()
+  call s:reset_all_buffers()
+
+  call s:make_simple_quickfix()
+  call assert_equal(1, winnr('$'))
+
+  " Quickfix code will open a split in an attempt to get a 'nowinfixbuf' window
+  " to switch buffers in.  Interfere with things by setting 'winfixbuf' in it.
+  augroup QfChanged
+    au!
+    au WinEnter * ++once call assert_equal(2, winnr('$'))
+          \| set winfixbuf | call setqflist([], 'f')
+  augroup END
+  call assert_fails('cnext', ['E1513:', 'E925:'])
+  " Check that the split was automatically closed.
+  call assert_equal(1, winnr('$'))
+
+  au! QfChanged
+  augroup! QfChanged
+endfunc
+
+func Test_bufdo_cnext_splitwin_fails()
+  call s:reset_all_buffers()
+  call s:make_simple_quickfix()
+  call assert_equal(1, getqflist(#{idx: 0}).idx)
+  " Make sure there is not enough room to
+  " split the winfixedbuf window
+  let &winheight=&lines
+  let &winminheight=&lines-2
+  " Still want E1513, or it may not be clear why a split was attempted and why
+  " it failing caused the commands to abort.
+  call assert_fails(':bufdo echo 1', ['E36:', 'E1513:'])
+  call assert_fails(':cnext', ['E36:', 'E1513:'])
+  " Ensure the entry didn't change.
+  call assert_equal(1, getqflist(#{idx: 0}).idx)
+  set winminheight&vim winheight&vim
+endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab