custom builtin previewer

[phanen]

• fix: some error when custom picker
• fix: detect filetype from content when no filename is given

[phanen]

not sure if my commit related to the failure. will see it later.

[phanen]

Author: zeertzjq <zeertzjq@outlook.com>
Date:   Sat Jan 3 17:55:07 2026 +0800

    fix(terminal): inconsistent mode change when switching buffer (#37215)
    
    Problem:  When switching to another terminal buffer in Terminal mode,
              usually Nvim stays in Terminal mode, but leaves Terminal mode
              if the old terminal buffer was deleted.
    Solution: Don't always leave Terminal mode when active terminal buffer
              is deleted. Instead let terminal_check_focus() decide that.

 src/nvim/terminal.c                           | 10 ++++++++--
 test/functional/terminal/ex_terminal_spec.lua | 30 +++++++++++++++++++++++++++++-
 2 files changed, 37 insertions(+), 3 deletions(-)

[phanen]

no better idea to fix, I just remove feedkey now.

[ibhagwan]

I see this will also close #2034.

btw, doesn’t seem like utils.ensure_startinsert is ever called.

[phanen]

btw, doesn’t seem like utils.ensure_startinsert is ever called.

That still fail non-nightly test. Now only remove feedkey on nightly.

[ibhagwan]

Now that CI is fixed on nightly is this ready to be merged or you need more time?

[phanen]

fix some lint.

[ibhagwan]

fix some lint.

You feel this is ready to be merged?

I won’t be able to properly test and merge this in a couple of days as traveling, aiming to merge this Thursday

[phanen]

Yeah, if it have issue i can fix it quickly.

[ibhagwan]

Yeah, if it have issue i can fix it quickly.

Alright I’ll merge it then, the start insert commit fixes #1659 (comment).

[phanen]

The latest 2 commit was to fix some window option issue. (just lazy to open another pr as usual...).

[phanen]

preview window still use "global" option, which means it will be inherit by new split window, and switched buffer. since it has issue like #2266.

Maybe this can also be fixed, but it's unusual to split a window from previewer, so let it as is.

[ibhagwan]

Thank you @phanen for these great changes.

Regarding the commit 383e605, say we had a complex regex in live grep and there are some discrepencies between the rg regex and vim.regex the reg:match_line could fail in which case we lose the exact highlighting of the match, the fallback makes it so that if we know the column (from the rg output directly) we can at least highlight one character where the match should begin.

For example say we search for fzf-lua and the result is in init.lua:1:10 (line 1 col 10) and for the sake of this example assume the regex match fails. we now highlight the first letter [f]zf-lua (instead of the entire string) so we can focus where the match begins.

This is also somewhat of a legacy since this is how live grep highlighting worked before the regex matching: cursor line to focus on the correct line, cursor char to focus on the right column.