From cbb41008fd43b512ffdbd35cebee2e4518b2181e Mon Sep 17 00:00:00 2001
From: Badel2 <2badel2@gmail.com>
Date: Fri, 19 May 2023 00:44:14 +0200
Subject: Fix overflow in error emitter

---
 compiler/rustc_errors/src/emitter.rs | 35 +++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)

(limited to 'compiler/rustc_errors/src/emitter.rs')

diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 68e57de5e08..3e38d6afb0b 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -2303,22 +2303,25 @@ impl EmitterWriter {
 
         // Colorize addition/replacements with green.
         for &SubstitutionHighlight { start, end } in highlight_parts {
-            // Account for tabs when highlighting (#87972).
-            let tabs: usize = line_to_add
-                .chars()
-                .take(start)
-                .map(|ch| match ch {
-                    '\t' => 3,
-                    _ => 0,
-                })
-                .sum();
-            buffer.set_style_range(
-                *row_num,
-                max_line_num_len + 3 + start + tabs,
-                max_line_num_len + 3 + end + tabs,
-                Style::Addition,
-                true,
-            );
+            // This is a no-op for empty ranges
+            if start != end {
+                // Account for tabs when highlighting (#87972).
+                let tabs: usize = line_to_add
+                    .chars()
+                    .take(start)
+                    .map(|ch| match ch {
+                        '\t' => 3,
+                        _ => 0,
+                    })
+                    .sum();
+                buffer.set_style_range(
+                    *row_num,
+                    max_line_num_len + 3 + start + tabs,
+                    max_line_num_len + 3 + end + tabs,
+                    Style::Addition,
+                    true,
+                );
+            }
         }
         *row_num += 1;
     }
-- 
cgit 1.4.1-3-g733a5