From e297a1d10730f2f3410d4353daa588241dd62a80 Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Sun, 30 Jun 2024 14:48:05 +0200
Subject: [PATCH] Handle unicode minus character when parsing floats

---
 crates/egui/src/widgets/drag_value.rs | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/crates/egui/src/widgets/drag_value.rs b/crates/egui/src/widgets/drag_value.rs
index 509dc5f9..1c237543 100644
--- a/crates/egui/src/widgets/drag_value.rs
+++ b/crates/egui/src/widgets/drag_value.rs
@@ -677,8 +677,14 @@ fn parse(custom_parser: &Option<NumParser<'_>>, value_text: &str) -> Option<f64>
 }
 
 fn default_parser(value_text: &str) -> Option<f64> {
-    // Ignore whitespace (trailing, leading, and thousands separators):
-    let value_text: String = value_text.chars().filter(|c| !c.is_whitespace()).collect();
+    let value_text: String = value_text
+        .chars()
+        // Ignore whitespace (trailing, leading, and thousands separators):
+        .filter(|c| !c.is_whitespace())
+        // Replace special minus character with normal minus (hyphen):
+        .map(|c| if c == '−' { '-' } else { c })
+        .collect();
+
     value_text.parse().ok()
 }
 
@@ -744,5 +750,16 @@ mod tests {
             Some(1_234_567.0),
             "We should handle thousands separators using half-space"
         );
+
+        assert_eq!(
+            super::default_parser("-1.23"),
+            Some(-1.23),
+            "Should handle normal hyphen as minus character"
+        );
+        assert_eq!(
+            super::default_parser("−1.23"),
+            Some(-1.23),
+            "Should handle special minus character (https://www.compart.com/en/unicode/U+2212)"
+        );
     }
 }