From 6e9ec99b50ff3a3fa9bd59f3be71b00560e56391 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Wed, 25 Mar 2026 16:42:25 +0300
Subject: [PATCH] vfmt: fix inconsistent wrapping of lines with + and - (fixes
 #25992)

---
 vlib/v/fmt/fmt.v                              | 27 ++++++++++++++-----
 .../fmt/tests/additive_infix_wrap_expected.vv | 11 ++++++++
 vlib/v/fmt/tests/additive_infix_wrap_input.vv |  9 +++++++
 .../tests/too_long_infix_expressions_keep.vv  |  3 ++-
 4 files changed, 42 insertions(+), 8 deletions(-)
 create mode 100644 vlib/v/fmt/tests/additive_infix_wrap_expected.vv
 create mode 100644 vlib/v/fmt/tests/additive_infix_wrap_input.vv

diff --git a/vlib/v/fmt/fmt.v b/vlib/v/fmt/fmt.v
index 2b873e828..552abd0bb 100644
--- a/vlib/v/fmt/fmt.v
+++ b/vlib/v/fmt/fmt.v
@@ -2552,7 +2552,9 @@ pub fn (mut f Fmt) index_expr(node ast.IndexExpr) {
 
 pub fn (mut f Fmt) infix_expr(node ast.InfixExpr) {
 	buffering_save := f.buffering
-	if !f.buffering && node.op in [.logical_or, .and, .plus] {
+	is_wrappable_additive_minus := node.op == .minus
+		&& (is_additive_infix(node.left) || is_additive_infix(node.right))
+	if !f.buffering && (node.op in [.logical_or, .and, .plus] || is_wrappable_additive_minus) {
 		f.buffering = true
 	}
 	is_assign_save := f.is_assign
@@ -2625,7 +2627,7 @@ pub fn (mut f Fmt) infix_expr(node ast.InfixExpr) {
 pub fn (mut f Fmt) wrap_infix(start_pos int, start_len int, is_cond bool) {
 	cut_span := f.out.len - start_pos
 	infix_str := f.out.cut_last(cut_span)
-	if !infix_str.contains_any_substr(['&&', '||', '+']) {
+	if !infix_str.contains_any_substr(['&&', '||', '+', '-']) {
 		f.write(infix_str)
 		return
 	}
@@ -2637,6 +2639,13 @@ pub fn (mut f Fmt) wrap_infix(start_pos int, start_len int, is_cond bool) {
 	f.write_splitted_infix(conditions, penalties, false, is_cond)
 }
 
+fn is_additive_infix(expr ast.Expr) bool {
+	return match expr {
+		ast.InfixExpr { expr.op in [.plus, .minus] }
+		else { false }
+	}
+}
+
 fn split_up_infix(infix_str string, ignore_paren bool, is_cond_infix bool) ([]string, []int) {
 	mut conditions := ['']
 	mut penalties := [5]
@@ -2654,11 +2663,15 @@ fn split_up_infix(infix_str string, ignore_paren bool, is_cond_infix bool) ([]st
 				conditions << '${p} '
 				ind++
 			}
-		} else if !is_cond_infix && p == '+' {
-			penalties << 5
-			conditions[ind] += '${p} '
-			conditions << ''
-			ind++
+		} else if !is_cond_infix && p in ['+', '-'] {
+			if inside_paren {
+				conditions[ind] += '${p} '
+			} else {
+				penalties << 5
+				conditions[ind] += '${p} '
+				conditions << ''
+				ind++
+			}
 		} else {
 			conditions[ind] += '${p} '
 			if ignore_paren {
diff --git a/vlib/v/fmt/tests/additive_infix_wrap_expected.vv b/vlib/v/fmt/tests/additive_infix_wrap_expected.vv
new file mode 100644
index 000000000..eef24f3e3
--- /dev/null
+++ b/vlib/v/fmt/tests/additive_infix_wrap_expected.vv
@@ -0,0 +1,11 @@
+fn main() {
+	long_var_name := 0
+
+	x := long_var_name + long_var_name + long_var_name + long_var_name + long_var_name +
+		long_var_name + long_var_name
+
+	y := long_var_name + long_var_name + long_var_name + long_var_name + long_var_name -
+		long_var_name - long_var_name
+
+	println(x + y)
+}
diff --git a/vlib/v/fmt/tests/additive_infix_wrap_input.vv b/vlib/v/fmt/tests/additive_infix_wrap_input.vv
new file mode 100644
index 000000000..c857a9d27
--- /dev/null
+++ b/vlib/v/fmt/tests/additive_infix_wrap_input.vv
@@ -0,0 +1,9 @@
+fn main() {
+	long_var_name := 0
+
+	x := long_var_name + long_var_name + long_var_name + long_var_name + long_var_name + long_var_name + long_var_name
+
+	y := long_var_name + long_var_name + long_var_name + long_var_name + long_var_name - long_var_name - long_var_name
+
+	println(x + y)
+}
diff --git a/vlib/v/fmt/tests/too_long_infix_expressions_keep.vv b/vlib/v/fmt/tests/too_long_infix_expressions_keep.vv
index 79c008407..217a03cbb 100644
--- a/vlib/v/fmt/tests/too_long_infix_expressions_keep.vv
+++ b/vlib/v/fmt/tests/too_long_infix_expressions_keep.vv
@@ -32,7 +32,8 @@ fn s_adjustsoundparams(listener &Abc, source &Abc, vol &int, sep &int) int {
 		if approx_dist > (1200 * (1 << 16)) {
 			approx_dist = (1200 * (1 << 16))
 		}
-		*vol = 15 +((snd_SfxVolume - 15) * (((1200 * (1 << 16)) - approx_dist) >> 16)) / (((1200 * (1 << 16)) - (200 * (1 << 16))) >> 16)
+		*vol = 15 + ((snd_SfxVolume - 15) * (((1200 * (1 << 16)) -
+			approx_dist) >> 16)) / (((1200 * (1 << 16)) - (200 * (1 << 16))) >> 16)
 	} else {
 		*vol = (snd_SfxVolume * (((1200 * (1 << 16)) - approx_dist) >> 16)) / (((1200 * (1 << 16)) - (200 * (1 << 16))) >> 16)
 	}
-- 
2.39.5