Commit: runtime(rust): Fix Rust indentation when string contains "if"

[Christian Brabandt]

runtime(rust): Fix Rust indentation when string contains "if"

Commit: https://github.com/vim/vim/commit/663d809194b471ebbdd9e270086c6d0ca53da8fd
Author: taylor.fish <con...@taylor.fish>
Date: Wed Jan 28 22:04:21 2026 +0000

runtime(rust): Fix Rust indentation when string contains "if"

indent/rust.vim behaves incorrectly when a string literal contains the
substring "if".

For example, in this code:

let x = "
motif
";
struct X {
}

indent/rust.vim thinks that the closing "}" should line up with "motif".

This patch fixes the issue by checking whether the "if" is in a string
literal or comment before considering it to be a match for a subsequent
brace (and also by requiring it to start on a word boundary).

Add an indent test to ensure this does not regress.

closes: #19265

Signed-off-by: taylor.fish <con...@taylor.fish>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/runtime/indent/rust.vim b/runtime/indent/rust.vim
index 30206be43..f449a19de 100644
--- a/runtime/indent/rust.vim
+++ b/runtime/indent/rust.vim
@@ -5,6 +5,7 @@
" 2024 Jul 04 by Vim Project: use shiftwidth() instead of hard-coding shifted values #15138
" 2025 Dec 29 by Vim Project: clean up
" 2025 Dec 31 by Vim Project: correcly indent after nested array literal #19042
+" 2026 Jan 28 by Vim Project: fix indentation when a string literal contains 'if' #19265

" For bugs, patches and license go to https://github.com/rust-lang/rust.vim
" Note: upstream seems umaintained: https://github.com/rust-lang/rust.vim/issues/502
@@ -139,9 +140,24 @@ function GetRustIndent(lnum)
let l:standalone_close = line =~# '\V\^\s\*}\s\*\$'
let l:standalone_where = line =~# '\V\^\s\*where\s\*\$'
if l:standalone_open || l:standalone_close || l:standalone_where
- " ToDo: we can search for more items than 'fn' and 'if'.
- let [l:found_line, l:col, l:submatch] =
- \ searchpos('\<\(fn\)\|\(if\)\>', 'bnWp')
+ let l:orig_line = line('.')
+ let l:orig_col = col('.')
+ let l:i = 0
+ while 1
+ " ToDo: we can search for more items than 'fn' and 'if'.
+ let [l:found_line, l:col, l:submatch] =
+ \ searchpos('\<\(fn\|if\)\>', 'bWp')
+ if l:found_line ==# 0 || !s:is_string_comment(l:found_line, l:col)
+ break
+ endif
+ let l:i += 1
+ " Limit to 10 iterations as a failsafe against endless looping.
+ if l:i >= 10
+ let l:found_line = 0
+ break
+ endif
+ endwhile
+ call cursor(l:orig_line, l:orig_col)
if l:found_line !=# 0
" Now we count the number of '{' and '}' in between the match
" locations and the current line (there is probably a better
diff --git a/runtime/indent/testdir/rust.in b/runtime/indent/testdir/rust.in
index 28a68924f..9b1912b23 100644
--- a/runtime/indent/testdir/rust.in
+++ b/runtime/indent/testdir/rust.in
@@ -40,3 +40,11 @@ fn main() {
// file goes out of scope, and the "hello.txt" file gets closed
}
// END_INDENT
+
+// START_INDENT
+let x = "
+ if fn motif
+ ";
+ struct X {
+ }
+// END_INDENT
diff --git a/runtime/indent/testdir/rust.ok b/runtime/indent/testdir/rust.ok
index 04808e224..73fff0620 100644
--- a/runtime/indent/testdir/rust.ok
+++ b/runtime/indent/testdir/rust.ok
@@ -40,3 +40,11 @@ fn main() {
// file goes out of scope, and the "hello.txt" file gets closed
}
// END_INDENT
+
+// START_INDENT
+let x = "
+ if fn motif
+ ";
+ struct X {
+}
+// END_INDENT