From 628f7b2b0cb6d7f1177bae3f2846047dae9b510c Mon Sep 17 00:00:00 2001
From: Ken Van Hoeylandt <git@kenvanhoeylandt.net>
Date: Wed, 7 Oct 2026 20:53:16 +0200
Subject: [PATCH] Fixes

---
 Modules/lvgl-module/source/insets_math.cpp       |  5 ++++-
 Tactility/Source/settings/AppearanceSettings.cpp | 10 +++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/Modules/lvgl-module/source/insets_math.cpp b/Modules/lvgl-module/source/insets_math.cpp
index a72092e99..14fcb2e7c 100644
--- a/Modules/lvgl-module/source/insets_math.cpp
+++ b/Modules/lvgl-module/source/insets_math.cpp
@@ -3,10 +3,13 @@
 
 #include <algorithm>
 #include <cmath>
+#include <numbers>
+
+constexpr double INV_SQRT2 = 1.0 / std::numbers::sqrt2;
 
 // The part of a corner's square that a circle with the given radius cuts off along its diagonal
 static int32_t corner_inset(int32_t radius) {
-    return static_cast<int32_t>(std::ceil(radius * (1.0 - M_SQRT1_2)));
+    return static_cast<int32_t>(std::ceil(radius * (1.0 - INV_SQRT2)));
 }
 
 // The horizontal distance between a circle's edge and its bounding box at the given distance from the circle's center row
diff --git a/Tactility/Source/settings/AppearanceSettings.cpp b/Tactility/Source/settings/AppearanceSettings.cpp
index a35d69f9e..0f751a275 100644
--- a/Tactility/Source/settings/AppearanceSettings.cpp
+++ b/Tactility/Source/settings/AppearanceSettings.cpp
@@ -5,6 +5,7 @@
 
 #include <app/paths.h>
 
+#include <charconv>
 #include <cinttypes>
 #include <cstdio>
 #include <cstdlib>
@@ -27,7 +28,14 @@ static std::optional<uint32_t> parseColor(const std::map<std::string, std::strin
     if (entry == map.end() || entry->second.empty()) {
         return std::nullopt;
     }
-    return static_cast<uint32_t>(std::strtoul(entry->second.c_str(), nullptr, 16)) & 0xFFFFFF;
+    // An invalid value (e.g. from a hand-edited file) counts as unset, rather than as black
+    const std::string& text = entry->second;
+    uint32_t color = 0;
+    const auto [end, error] = std::from_chars(text.data(), text.data() + text.size(), color, 16);
+    if (error != std::errc {} || end != text.data() + text.size() || color > 0xFFFFFF) {
+        return std::nullopt;
+    }
+    return color;
 }
 
 // Saving only updates the keys that are written, so an unset colour is written as an empty value