Commit: runtime(rust): use textwidth=100 for the Rust recommended style

[Christian Brabandt]

runtime(rust): use textwidth=100 for the Rust recommended style

Commit: https://github.com/vim/vim/commit/98ef8433b654ee96c57b66348b767edc73a44406
Author: Aaron Jacobs <jac...@google.com>
Date: Tue Dec 9 12:43:39 2025 +0100

runtime(rust): use textwidth=100 for the Rust recommended style

The help text here said 99 was the recommended style for the standard
library, but I can't find a citation for this anywhere. In contrast the
Rust Style Guide hosted on rust-lang.org
[says](https://doc.rust-lang.org/stable/style-guide/#indentation-and-line-width)
the maximum line width is 100, and rustfmt
[agrees](https://github.com/rust-lang/rust/blob/37aa2135b5d0936bd13aa699d941aaa94fbaa645/src/tools/rustfmt/src/config/options.rs#L570).

Having the two disagree causes an annoying off-by-one error in vim: if
you configure vim to highlight too-long lines then it will occasionally
complain about a line that rustfmt refuses to fix.

closes: #18892

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

diff --git a/runtime/doc/ft_rust.txt b/runtime/doc/ft_rust.txt
index 4f4e3a85e..b1789b814 100644
--- a/runtime/doc/ft_rust.txt
+++ b/runtime/doc/ft_rust.txt
@@ -60,8 +60,8 @@ g:rust_conceal_pub~
*g:rust_recommended_style*
g:rust_recommended_style~
Set this option to enable vim indentation and textwidth settings to
- conform to style conventions of the rust standard library (i.e. use 4
- spaces for indents and sets 'textwidth' to 99). This option is enabled
+ conform to style conventions of the Rust style guide (i.e. use 4
+ spaces for indents and set 'textwidth' to 100). This option is enabled
by default. To disable it: >
let g:rust_recommended_style = 0
<
diff --git a/runtime/ftplugin/rust.vim b/runtime/ftplugin/rust.vim
index 3e2741f91..4765f8170 100644
--- a/runtime/ftplugin/rust.vim
+++ b/runtime/ftplugin/rust.vim
@@ -3,6 +3,7 @@
" Maintainer: Chris Morgan <m...@chrismorgan.info>
" Last Change: 2024 Mar 17
" 2024 May 23 by Riley Bruins <rib...@gmail.com ('commentstring')
+" 2025 Dec 09 update 'textwidth# to 100 #18892
" For bugs, patches and license go to https://github.com/rust-lang/rust.vim

if exists("b:did_ftplugin")
@@ -49,7 +50,7 @@ setlocal smartindent nocindent
if get(g:, 'rust_recommended_style', 1)
let b:rust_set_style = 1
setlocal shiftwidth=4 softtabstop=4 expandtab
- setlocal textwidth=99
+ setlocal textwidth=100
endif

setlocal include=\v^\s*(pub\s+)?use\s+\zs(\f\|:)+