Commit: runtime(rust): Do not use rustfmt as 'formatprg' by default

[Christian Brabandt]

runtime(rust): Do not use rustfmt as 'formatprg' by default

Commit: https://github.com/vim/vim/commit/eba51337d4b8051b768164f3394d680742234ca8
Author: Aaron Jacobs <jac...@google.com>
Date: Mon Oct 27 17:46:11 2025 +0000

runtime(rust): Do not use rustfmt as 'formatprg' by default

This reverts commit 4ac995bf9366c6624a0724d19b2226f4c95694b3.

This was added in #16807, with no explanation for why it was necessary beyond
"it's an example of an idea". It completely breaks `gq` for me—rustfmt doesn't
reflow comments so is not an appropriate tool here! Beyond that, formatting a
selection with rustfmt treats that selection as if it were an entire file,
throwing away any indentation.

For example, the commit causes `gq` to turn this:

```rust
pub fn foo() {
// blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah
}
```

into this:

```rust
pub fn foo() {
// blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah
}

```

which is totally wrong. In contrast, if I clear `formatprg` then `gq` does the
right thing again:

```rust
pub fn foo() {
// blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah
// blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah
// blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah
// blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah
// blah blah blah blah blah blah
}
```

related: #16967
related: #17055
closes: #18640

Signed-off-by: Aaron Jacobs <jac...@google.com>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/runtime/autoload/rustfmt.vim b/runtime/autoload/rustfmt.vim
index 847b698b7..268a1c02c 100644
--- a/runtime/autoload/rustfmt.vim
+++ b/runtime/autoload/rustfmt.vim
@@ -1,8 +1,8 @@
" Author: Stephen Sugden <ste...@stephensugden.com>
" Last Modified: 2023-09-11
" Last Change:
-" 2025 Mar 31 by Vim project (rename s:RustfmtConfigOptions())
-" 2025 Jul 14 by Vim project (don't parse rustfmt version automatically #17745)
+" 2025 Oct 27 by Vim project don't use rustfmt as 'formatprg' by default
+"
"
" Adapted from https://github.com/fatih/vim-go
" For bugs, patches and license go to https://github.com/rust-lang/rust.vim
@@ -68,13 +68,7 @@ function! s:RustfmtWriteMode()
endif
endfunction

-function! rustfmt#RustfmtConfigOptions()
- let default = '--edition 2018'
-
- if !get(g:, 'rustfmt_find_toml', 0)
- return default
- endif
-
+function! s:RustfmtConfigOptions()
let l:rustfmt_toml = findfile('rustfmt.toml', expand('%:p:h') . ';')
if l:rustfmt_toml !=# ''
return '--config-path '.shellescape(fnamemodify(l:rustfmt_toml, ":p"))
@@ -97,7 +91,7 @@ function! s:RustfmtCommandRange(filename, line1, line2)

let l:arg = {"file": shellescape(a:filename), "range": [a:line1, a:line2]}
let l:write_mode = s:RustfmtWriteMode()
- let l:rustfmt_config = rustfmt#RustfmtConfigOptions()
+ let l:rustfmt_config = s:RustfmtConfigOptions()

" FIXME: When --file-lines gets to be stable, add version range checking
" accordingly.
@@ -112,7 +106,7 @@ endfunction

function! s:RustfmtCommand()
let write_mode = g:rustfmt_emit_files ? '--emit=stdout' : '--write-mode=display'
- let config = rustfmt#RustfmtConfigOptions()
+ let config = s:RustfmtConfigOptions()
return join([g:rustfmt_command, write_mode, config, g:rustfmt_options])
endfunction

diff --git a/runtime/doc/ft_rust.txt b/runtime/doc/ft_rust.txt
index 30b23ced1..4f4e3a85e 100644
--- a/runtime/doc/ft_rust.txt
+++ b/runtime/doc/ft_rust.txt
@@ -166,13 +166,6 @@ g:rustfmt_detect_version~
Disabled by default for performance reasons
>
let g:rustfmt_detect_version = 1
-<
- *g:rustfmt_find_toml*
-g:rustfmt_emit_files~
- When set to 1, will try to find "rustfmt.toml" file by searching from
- current path upwards. Disabled by default for performance reasons
->
- let g:rustfmt_find_toml = 1
<
*g:rust_playpen_url*
g:rust_playpen_url~
diff --git a/runtime/ftplugin/rust.vim b/runtime/ftplugin/rust.vim
index 53f7f8336..3e2741f91 100644
--- a/runtime/ftplugin/rust.vim
+++ b/runtime/ftplugin/rust.vim
@@ -3,7 +3,6 @@
" Maintainer: Chris Morgan <m...@chrismorgan.info>
" Last Change: 2024 Mar 17
" 2024 May 23 by Riley Bruins <rib...@gmail.com ('commentstring')
-" 2025 Mar 31 by Vim project (set 'formatprg' option)
" For bugs, patches and license go to https://github.com/rust-lang/rust.vim

if exists("b:did_ftplugin")
@@ -58,19 +57,6 @@ setlocal includeexpr=rust#IncludeExpr(v:fname)

setlocal suffixesadd=.rs

-if executable(get(g:, 'rustfmt_command', 'rustfmt'))
- if get(g:, "rustfmt_fail_silently", 0)
- augroup rust.vim.FailSilently
- autocmd! * <buffer>
- autocmd ShellFilterPost <buffer> if v:shell_error | execute 'echom "shell filter returned error " . v:shell_error . ", undoing changes"' | undo | endif
- augroup END
- endif
-
- let &l:formatprg = get(g:, 'rustfmt_command', 'rustfmt') . ' ' .
- \ get(g:, 'rustfmt_options', '') . ' ' .
- \ rustfmt#RustfmtConfigOptions()
-endif
-
if exists("g:ftplugin_rust_source_path")
let &l:path=g:ftplugin_rust_source_path . ',' . &l:path
endif
@@ -163,7 +149,7 @@ endif

let b:undo_ftplugin = "
\ compiler make |
- \ setlocal formatoptions< comments< commentstring< include< includeexpr< suffixesadd< formatprg<
+ \ setlocal formatoptions< comments< commentstring< include< includeexpr< suffixesadd<
\|if exists('b:rust_set_style')
\|setlocal tabstop< shiftwidth< softtabstop< expandtab< textwidth<
\|endif