Remove WM_LIST, which was previously added in #7110, but now statusline
and messages no longer interfere with each other thanks to the message
grid, etc., and terminal refreshing no longer calls update_screen()
directly since #9883.
Tests from #7110 and #10107 still pass.
Problem: More code can be moved to evalvars.c.
Solution: Move code to where it fits better. (Yegappan Lakshmanan,
closesvim/vim#4883)
da6c033421
Co-authored-by: Bram Moolenaar <Bram@vim.org>
Problem: The ops.c file is too big.
Solution: Move code for dealing with registers to a new file. (Yegappan
Lakshmanan, closesvim/vim#4982)
4aea03eb87
Co-authored-by: Bram Moolenaar <Bram@vim.org>
Problem: complete: some redraw issues with 'autocomplete'
Solution: Fix the issues (Girish Palya)
This commit contains the following changes:
* Fix that wildtrigger() might leave opened popupmenu around vim/vim#18298
* Remove blinking message on the command line when a menu item from a loaded
buffer is selected during 'autocomplete'
* Add a test for PR vim/vim#18265 to demonstrate why the PR is required for correct
'autocomplete' behavior
fixes: vim/vim#18298closes: vim/vim#18328ee9a2f0512
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: When the popup menu (PUM) occupies more than half the screen
height, it flickers whenever a character is typed or erased.
This happens because the PUM is cleared and the screen is
redrawn before a new PUM is rendered. The extra redraw between
menu updates causes visible flicker.
Solution: A complete, non-hacky fix would require removing the
CmdlineChanged event from the loop and letting autocompletion
manage the process end-to-end. This is because screen redraws
after any cmdline change are necessary for other features to
work.
This change modifies wildtrigger() so that the next typed
character defers the screen update instead of redrawing
immediately. This removes the intermediate redraw, eliminating
flicker and making cmdline autocompletion feel smooth
(Girish Palya).
Trade-offs:
This behavior change in wildtrigger() is tailored specifically for
:h cmdline-autocompletion. wildtrigger() now has no general-purpose use
outside this scenario.
closes: vim/vim#17932da9c966893
Use pum_check_clear() instead of update_screen().
Cherry-pick Test_wildtrigger_update_screen() change from patch 9.1.1682.
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: cmdline-autocompletion breaks history navigation (ddad431)
Solution: Support history navigation in cmdline autocompletion (Girish
Palya)
Up/Down arrows support history navigation when using wildtrigger()
fixes: vim/vim#18207closes: vim/vim#18219708ab7f5fb
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: Matches may be listed twice with wildmode=longest,list when
"longest" doesn't change command line (after 9.1.1737).
Solution: Set did_wild_list when trying "list" after "longest"
(zeertzjq).
closes: vim/vim#18227a28a2eb9d9
Problem: Patch v9.1.1714 introduce a regression for wildmenu (zeertzjq)
Solution: Restore behavior of "longest" in 'wildmode' (Girish Palya)
- Fixed a regression caused by PR vim/vim#18125 selecting wrong item
- Fixed another regression where the first pasted text did not appear on
the command-line after starting Vim.
closes: vim/vim#182128fec92d631
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: completion: long line shown twice
(Maxim Kim)
Solution: Fix the issue, disable an incorrect test.
(Girish Palya)
fixes: vim/vim#18035closes: vim/vim#1808857379302aa
Omit removal of blank line in Test_noselect_expand_env_var() as it's
added again in patch 9.1.1682.
Cherry-pick two blank lines in Test_long_line_noselect() from patch
9.1.1682.
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: During commandline completiom, popup window placement can be
incorrect when 'noselect' is present in 'wildmode'
(Shane-XB-Qian)
Solution: Disable "showtail" feature when 'noselect' is present.
fixes: vim/vim#17969closes: vim/vim#180011e38198a41
Partial port excluding the showtail change and the test.
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: CmdlineChanged not triggered by <Del>
Solution: Use STRCMP() instead of STRNCMP()
(Shougo Matsushita)
closes: vim/vim#18101540480697d
Co-authored-by: Shougo Matsushita <Shougo.Matsu@gmail.com>
These are not needed after #35129 but making uncrustify still play nice
with them was a bit tricky.
Unfortunately `uncrustify --update-config-with-doc` breaks strings
with backslashes. This issue has been reported upstream,
and in the meanwhile auto-update on every single run has been disabled.
Problem: parse_cmdline() sets eap->cmdlinep to address of local parameter,
causing invalid memory access when expand_filename() tries to modify it.
This leads to crashes when typing '%' in user commands with preview=true
and complete=file.
Solution: Change parse_cmdline() signature to accept char **cmdline,
allowing cmdlinep to point to caller's variable for safe reallocation.
Problem:
During preview, the `input` still prompts the user to enter something
that won't be used later, which could be a bit confusing.
e.g., `:s/a/\=input("")`.
Solution:
Make the input() return early during 'inccommand' preview.
Problem: Ctrl-G/Ctrl-T does not ignore the end search delimiter
(irisjae)
Solution: Check if the pattern ends with a search delimiter and ignore
it, unless it is part of the pattern.
fixes: vim/vim#17895closes: vim/vim#17933c03990d30f
Co-authored-by: Christian Brabandt <cb@256bit.org>
Problem: completion: incsearch highlight might be lost after search
completion (Hirohito Higashi)
Solution: Restore incsearch highlight after dismissing pum with Ctrl-E
(Girish Palya)
related: vim/vim#17870closes: vim/vim#1789104c9e78cd3
This change actually isn't needed as Nvim doesn't call update_screen()
to redraw pum, but it doesn't hurt either.
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: cannot easily trigger wildcard expansion
Solution: Introduce wildtrigger() function
(Girish Palya)
This PR introduces a new `wildtrigger()` function.
See `:h wildtrigger()`
`wildtrigger()` behaves like pressing the `wildchar,` but provides a
more refined and controlled completion experience:
- Suppresses beeps when no matches are found.
- Avoids displaying irrelevant completions (like full command lists)
when the prefix is insufficient or doesn't match.
- Skips completion if the typeahead buffer has pending input or if a
wildmenu is already active.
- Does not print "..." before completion.
This is an improvement on the `feedkeys()` based autocompletion script
given in vim/vim#16759.
closes: vim/vim#17806b486ed8266
While at it, also make Ctrl-Z trigger search completion.
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: Memory leak when pressing Ctrl-D in cmdline mode
(after 9.1.1571).
Solution: Free prev_cmdbuff before assigning to it.
(zeertzjq).
Existing tests already cover this. This change fixes the CI failure.
closes: vim/vim#17807c02bef26fd
Problem: The CmdlineChanged event was firing unnecessarily, even when
the command line's content hadn't actually changed.
Solution: I've added a check to compare the command-line buffer's state
before and after key processing. The `CmdlineChanged` event
now only triggers if the buffer's contents are genuinely
different (Girish Palya).
closes: vim/vim#17803239c4e4abe
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: Hardcoded highlight IDs for ext_messages/cmdline output need
to be adjusted everytime a builtin highlight group is added.
Solution: Store a global map of default highlights through nvim_get_hl()
and fetch missing (custom) highlight groups through synIDattr().
Use more compact formatting for screen:expect().
Problem: getcompletiontype() crashes when no completion is available
(after v9.1.1509).
Solution: Don't call set_expand_context() (zeertzjq)
fixes: vim/vim#17681closes: vim/vim#17684e2c0f81dd0
Problem: tests: no test that 'incsearch' is updated after accepting
search completion.
Solution: Add a test case (zeertzjq).
closes: vim/vim#1768208e5b128b8
Problem: Patch 9.1.1505 was not good
Solution: Revert "patch 9.1.1505: not possible to return completion type
for :ex command" and instead add the getcompletiontype()
function (Hirohito Higashi).
related: vim/vim#17606closes: vim/vim#1766296b3ef2389
Cherry-pick Test_multibyte_expression() from Vim, as it passes.
Co-authored-by: Hirohito Higashi <h.east.727@gmail.com>
Co-authored-by: Shougo Matsushita <Shougo.Matsu@gmail.com>
Problem: not possible to return command-line completion type for :ex
command
Solution: make getcmdcompltype() accept an optional and return the
command-line completion for that arg (Shougo Matsushita).
closes: vim/vim#176065d2354fc07
Co-authored-by: Shougo Matsushita <Shougo.Matsu@gmail.com>
Problem: 'wildchar' does not work in search contexts
Solution: implement search completion when 'wildchar' is typed
(Girish Palya).
This change enhances Vim's command-line completion by extending
'wildmode' behavior to search pattern contexts, including:
- '/' and '?' search commands
- ':s', ':g', ':v', and ':vim' commands
Completions preserve the exact regex pattern typed by the user,
appending the completed word directly to the original input. This
ensures that all regex elements — such as '<', '^', grouping brackets
'()', wildcards '\*', '.', and other special characters — remain intact
and in their original positions.
---
**Use Case**
While searching (using `/` or `?`) for lines containing a pattern like
`"foobar"`, you can now type a partial pattern (e.g., `/f`) followed by
a trigger key (`wildchar`) to open a **popup completion menu** showing
all matching words.
This offers two key benefits:
1. **Precision**: Select the exact word you're looking for without
typing it fully.
2. **Memory aid**: When you can’t recall a full function or variable
name, typing a few letters helps you visually identify and complete the
correct symbol.
---
**What’s New**
Completion is now supported in the following contexts:
- `/` and `?` search commands
- `:s`, `:g`, `:v`, and `:vimgrep` ex-commands
---
**Design Notes**
- While `'wildchar'` (usually `<Tab>`) triggers completion, you'll have
to use `<CTRL-V><Tab>` or "\t" to search for a literal tab.
- **Responsiveness**: Search remains responsive because it checks for
user input frequently.
---
**Try It Out**
Basic setup using the default `<Tab>` as the completion trigger:
```vim
set wim=noselect,full wop=pum wmnu
```
Now type:
```
/foo<Tab>
```
This opens a completion popup for matches containing "foo".
For matches beginning with "foo" type `/\<foo<Tab>`.
---
**Optional: Autocompletion**
For automatic popup menu completion as you type in search or `:`
commands, include this in your `.vimrc`:
```vim
vim9script
set wim=noselect:lastused,full wop=pum wcm=<C-@> wmnu
autocmd CmdlineChanged [:/?] CmdComplete()
def CmdComplete()
var [cmdline, curpos, cmdmode] = [getcmdline(), getcmdpos(),
expand('<afile>') == ':']
var trigger_char = '\%(\w\|[*/:.-]\)$'
var not_trigger_char = '^\%(\d\|,\|+\|-\)\+$' # Exclude numeric range
if getchar(1, {number: true}) == 0 # Typehead is empty, no more
pasted input
&& !wildmenumode() && curpos == cmdline->len() + 1
&& (!cmdmode || (cmdline =~ trigger_char && cmdline !~
not_trigger_char))
SkipCmdlineChanged()
feedkeys("\<C-@>", "t")
timer_start(0, (_) => getcmdline()->substitute('\%x00', '',
'ge')->setcmdline()) # Remove <C-@>
endif
enddef
def SkipCmdlineChanged(key = ''): string
set ei+=CmdlineChanged
timer_start(0, (_) => execute('set ei-=CmdlineChanged'))
return key == '' ? '' : ((wildmenumode() ? "\<C-E>" : '') .. key)
enddef
**Optional: Preserve history recall behavior**
cnoremap <expr> <Up> SkipCmdlineChanged("\<Up>")
cnoremap <expr> <Down> SkipCmdlineChanged("\<Down>")
**Optional: Customize popup height**
autocmd CmdlineEnter : set bo+=error | exec $'set ph={max([10,
winheight(0) - 4])}'
autocmd CmdlineEnter [/?] set bo+=error | set ph=8
autocmd CmdlineLeave [:/?] set bo-=error ph&
```
closes: vim/vim#175706b49fba8c8
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: no easy way to deduplicate text
Solution: add the :uniq ex command
(Hirohito Higashi)
closes: vim/vim#1753874f0a77bb9
Co-authored-by: Hirohito Higashi <h.east.727@gmail.com>
Problem: ml_get error when using <Cmd> to open a terminal.
Solution: If the window changed reset the incsearch state. (closesvim/vim#7289)
f4d61bc559
Co-authored-by: Bram Moolenaar <Bram@vim.org>
Problem: ext_messages is implemented to mimic the message grid
implementation w.r.t. scrolling messages, clearing scrolled
messages, hit-enter-prompts and replacing a previous message.
Meanwhile, an ext_messages UI may not be implemented in a way
where these events are wanted. Moreover, correctness of these
events even assuming a "scrolled message" implementation
depends on fragile "currently visible messages" global state,
which already isn't correct after a previous message was
supposed to have been overwritten (because that should not only
happen when `msg_scroll == false`).
Solution: - No longer attempt to keep track of the currently visible
messages: remove the `msg_ext(_history)_visible` variables.
UIs may remove messages pre-emptively (timer based), or never
show messages that don't fit a certain area in the first place.
- No longer emit the `msg(_history)_clear` events to clear
"scrolled" messages. This opens up the `msg_clear` event to
be emitted when messages should actually be cleared (e.g.
when the screen is cleared). May also be useful to emit before
the first message in an event loop cycle as a hint to the UI
that it is a new batch of messages (vim._extui currently
schedules an event to determine that).
- Set `replace_last` explicitly at the few callsites that want
this to be set to true to replace an incomplete status message.
- Don't store a "keep" message to be re-emitted.
Problem: "cmdline_show" event may be emitted with an invalid cursor
position, causing a redraw that will clear the match highlight.
Solution: Mark the cursor position as valid so that a "cmdline_show"
callback that updates the screen does not clear the match highlight.
Problem: vim.ui_attach cmdline events emitted with an ephemeral cursor
position that is only used as the start of the search.
Solution: Delay setting the cursor position until after ui_flush().
Problem: UIs implementing ext_cmdline/message must also implement
ext_popupmenu in order to get cmdline completion with
wildoptions+=pum.
Solution: Allow marking a window as the ext_cmdline window through
nvim_open_win(), including prompt offset. Anchor the cmdline-
completion popupmenu to this window.
Problem: Return value of getcmdline() inconsistent in CmdlineLeavePre
when leaving cmdline in different ways (after v9.1.1329).
Solution: Trigger CmdlineLeavePre before calling abandon_cmdline() so
that getcmdline() can return the command line (zeertzjq).
closes: vim/vim#172189240369774
Problem: CmdlineLeavePre may trigger twice
(after v9.1.1329)
Solution: check that the key was typed, trigger it when it wasn't before
(Girish Palya)
There are two problems:
- CmdlineLeavePre may be triggered twice when a cabbr is present.
- CmdlineLeavePre fails to trigger when exiting the command-line via
<Backspace>.
Check if the Carriage Return (Enter) key was actually typed.
Trigger the event when the command-line is exited using Backspace and
other keys.
closes: vim/vim#1721446755e6b52
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: cannot get information about command line completion
Solution: add CmdlineLeavePre autocommand and cmdcomplete_info() Vim
script function (Girish Palya)
This commit introduces two features to improve introspection and control
over command-line completion in Vim:
- Add CmdlineLeavePre autocmd event:
A new event triggered just before leaving the command line and before
CmdlineLeave. It allows capturing completion-related state that is
otherwise cleared by the time CmdlineLeave fires.
- Add cmdcomplete_info() Vim script function:
Returns a Dictionary with details about the current command-line
completion state.
These are similar in spirit to InsertLeavePre and complete_info(),
but focused on command-line mode.
**Use case:**
In [[PR vim/vim#16759](https://github.com/vim/vim/pull/16759)], two examples
demonstrate command-line completion: one for live grep, and another for
fuzzy file finding. However, both examples share two key limitations:
1. **Broken history recall (`<Up>`)**
When selecting a completion item via `<Tab>` or `<C-n>`, the original
pattern used for searching (e.g., a regex or fuzzy string) is
overwritten in the command-line history. This makes it impossible to
recall the original query later.
This is especially problematic for interactive grep workflows, where
it’s useful to recall a previous search and simply select a different
match from the menu.
2. **Lack of default selection on `<CR>`**
Often, it’s helpful to allow `<CR>` (Enter) to accept the first match
in the completion list, even when no item is explicitly selected. This
behavior is particularly useful in fuzzy file finding.
----
Below are the updated examples incorporating these improvements:
**Live grep, fuzzy find file, fuzzy find buffer:**
```vim
command! -nargs=+ -complete=customlist,GrepComplete Grep VisitFile()
def GrepComplete(arglead: string, cmdline: string, cursorpos: number):
list<any>
return arglead->len() > 1 ? systemlist($'grep -REIHns "{arglead}"' ..
' --exclude-dir=.git --exclude=".*" --exclude="tags" --exclude="*.swp"') : []
enddef
def VisitFile()
if (selected_match != null_string)
var qfitem = getqflist({lines: [selected_match]}).items[0]
if qfitem->has_key('bufnr') && qfitem.lnum > 0
var pos = qfitem.vcol > 0 ? 'setcharpos' : 'setpos'
exec $':b +call\ {pos}(".",\ [0,\ {qfitem.lnum},\ {qfitem.col},\ 0]) {qfitem.bufnr}'
setbufvar(qfitem.bufnr, '&buflisted', 1)
endif
endif
enddef
nnoremap <leader>g :Grep<space>
nnoremap <leader>G :Grep <c-r>=expand("<cword>")<cr>
command! -nargs=* -complete=customlist,FuzzyFind Find
execute(selected_match != '' ? $'edit {selected_match}' : '')
var allfiles: list<string>
autocmd CmdlineEnter : allfiles = null_list
def FuzzyFind(arglead: string, _: string, _: number): list<string>
if allfiles == null_list
allfiles = systemlist($'find {get(g:, "fzfind_root", ".")} \! \(
-path "*/.git" -prune -o -name "*.swp" \) -type f -follow')
endif
return arglead == '' ? allfiles : allfiles->matchfuzzy(arglead)
enddef
nnoremap <leader><space> :<c-r>=execute('let
fzfind_root="."')\|''<cr>Find<space><c-@>
nnoremap <leader>fv :<c-r>=execute('let
fzfind_root="$HOME/.vim"')\|''<cr>Find<space><c-@>
nnoremap <leader>fV :<c-r>=execute('let
fzfind_root="$VIMRUNTIME"')\|''<cr>Find<space><c-@>
command! -nargs=* -complete=customlist,FuzzyBuffer Buffer execute('b '
.. selected_match->matchstr('\d\+'))
def FuzzyBuffer(arglead: string, _: string, _: number): list<string>
var bufs = execute('buffers', 'silent!')->split("\n")
var altbuf = bufs->indexof((_, v) => v =~ '^\s*\d\+\s\+#')
if altbuf != -1
[bufs[0], bufs[altbuf]] = [bufs[altbuf], bufs[0]]
endif
return arglead == '' ? bufs : bufs->matchfuzzy(arglead)
enddef
nnoremap <leader><bs> :Buffer <c-@>
var selected_match = null_string
autocmd CmdlineLeavePre : SelectItem()
def SelectItem()
selected_match = ''
if getcmdline() =~ '^\s*\%(Grep\|Find\|Buffer\)\s'
var info = cmdcomplete_info()
if info != {} && info.pum_visible && !info.matches->empty()
selected_match = info.selected != -1 ? info.matches[info.selected] : info.matches[0]
setcmdline(info.cmdline_orig). # Preserve search pattern in history
endif
endif
enddef
```
**Auto-completion snippet:**
```vim
set wim=noselect:lastused,full wop=pum wcm=<C-@> wmnu
autocmd CmdlineChanged : CmdComplete()
def CmdComplete()
var [cmdline, curpos] = [getcmdline(), getcmdpos()]
if getchar(1, {number: true}) == 0 # Typehead is empty (no more pasted input)
&& !pumvisible() && curpos == cmdline->len() + 1
&& cmdline =~ '\%(\w\|[*/:.-]\)$' && cmdline !~ '^\d\+$' # Reduce noise
feedkeys("\<C-@>", "ti")
SkipCmdlineChanged() # Suppress redundant completion attempts
# Remove <C-@> that get inserted when no items are available
timer_start(0, (_) => getcmdline()->substitute('\%x00', '', 'g')->setcmdline())
endif
enddef
cnoremap <expr> <up> SkipCmdlineChanged("\<up>")
cnoremap <expr> <down> SkipCmdlineChanged("\<down>")
autocmd CmdlineEnter : set bo+=error
autocmd CmdlineLeave : set bo-=error
def SkipCmdlineChanged(key = ''): string
set ei+=CmdlineChanged
timer_start(0, (_) => execute('set ei-=CmdlineChanged'))
return key != '' ? ((pumvisible() ? "\<c-e>" : '') .. key) : ''
enddef
```
These customizable snippets can serve as *lightweight* and *native*
alternatives to picker plugins like **FZF** or **Telescope** for common,
everyday workflows. Also, live grep snippet can replace **cscope**
without the overhead of building its database.
closes: vim/vim#1711592f68e26ec
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: Unnecessary use of STRCAT() in au_event_disable(). STRCAT()
seeks to the end of new_ei, but here the end is already known.
Solution: Use STRCPY() and add p_ei_len to new_ei. Also fix a typo in a
comment. Add a test that 'eventignore' works in :argdo
(zeertzjq).
closes: vim/vim#16844969e11a18b
Cherry-pick p_ei_len from patch 9.1.0256.
Problem: wrong flags passed down to nextwild()
(zeertzjq, after v9.1.1166)
Solution: only pass options flags (Girish Palya)
`options` needs to be passed into nextwild() since it may contain
WILD_KEEP_SOLE_ITEM which prevents the menu items list from getting
freed if there is only 1 item left (if `noselect` is set).
closes: vim/vim#16778d2219d547d
Co-authored-by: Girish Palya <girishji@gmail.com>
Problem: command-line auto-completion hard with wildmenu
Solution: implement "noselect" wildoption value (Girish Palya)
When `noselect` is present in `wildmode` and 'wildmenu' is enabled, the
completion menu appears without pre-selecting the first item.
This change makes it easier to implement command-line auto-completion,
where the menu dynamically appears as characters are typed, and `<Tab>`
can be used to manually select an item. This can be achieved by
leveraging the `CmdlineChanged` event to insert `wildchar(m)`,
triggering completion menu.
Without this change, auto-completion using the 'wildmenu' mechanism is
not feasible, as it automatically inserts the first match, preventing
dynamic selection.
The following Vimscript snippet demonstrates how to configure
auto-completion using `noselect`:
```vim
vim9script
set wim=noselect:lastused,full wop=pum wcm=<C-@> wmnu
autocmd CmdlineChanged : timer_start(0, function(CmdComplete, [getcmdline()]))
def CmdComplete(cur_cmdline: string, timer: number)
var [cmdline, curpos] = [getcmdline(), getcmdpos()]
if cur_cmdline ==# cmdline # Avoid completing each character in keymaps and pasted text
&& !pumvisible() && curpos == cmdline->len() + 1
if cmdline[curpos - 2] =~ '[\w*/:]' # Reduce noise by completing only selected characters
feedkeys("\<C-@>", "ti")
set eventignore+=CmdlineChanged # Suppress redundant completion attempts
timer_start(0, (_) => {
getcmdline()->substitute('\%x00$', '', '')->setcmdline() # Remove <C-@> if no completion items exist
set eventignore-=CmdlineChanged
})
endif
endif
enddef
```
fixes: vim/vim#16551closes: vim/vim#167592bacc3e5fb
Cherry-pick Wildmode_Tests() change from patch 9.0.0418.
Co-authored-by: Girish Palya <girishji@gmail.com>
Signed-off-by: Tomas Slusny <slusnucky@gmail.com>
Problem: `cmdline_show` is emitted unnecessarily each event
loop iteration, because `cmdline_was_last_drawn` is never set.
Solution: Keep track of whether the cmdline was last drawn to avoid
unnecessarily emitting cmdline_show. Set `redraw_state` to
emit `cmdline_pos` when emitting `CursorMovedC`. Only emit
`cmdline_pos` when cmdline was last drawn.
Problem:
Incremental preview is not allowed on 'nomodifiable' buffers.
Solution:
- Allow preview on 'nomodifiable' buffers.
- Restore the 'modifiable' option in case the preview function changes it.
