From fc36af302b25b79cf3d1798e2c584a2df03c9036 Mon Sep 17 00:00:00 2001
From: Bryan Malyn <bim9262@gmail.com>
Date: Mon, 18 Aug 2025 19:00:05 -0500
Subject: [PATCH] Omit line number for toml parse error for unknown spans

In the case that the span is (0..0), we don't usually know where the
error really occurred. In that case just omit the line number.

Resolves: #2189

This error is tracked upstream:

* toml: https://github.com/toml-rs/toml/issues/589
* serde: https://github.com/serde-rs/serde/issues/1183
---
 src/util.rs | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/util.rs b/src/util.rs
index eaadce60a8..339130c290 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -99,11 +99,15 @@ where
         let location_msg = err
             .span()
             .map(|span| {
-                let line = 1 + contents.as_bytes()[..(span.start)]
-                    .iter()
-                    .filter(|b| **b == b'\n')
-                    .count();
-                format!(" at line {line}")
+                if span == (0..0) {
+                    String::new()
+                } else {
+                    let line = 1 + contents.as_bytes()[..(span.start)]
+                        .iter()
+                        .filter(|b| **b == b'\n')
+                        .count();
+                    format!(" at line {line}")
+                }
             })
             .unwrap_or_default();
         Error::new(format!(