fix: sonarqube security hotspot fix

README.md

@@ -1,6 +1,6 @@
 # Card Collection Manager 3
 
-[![SonarCloud Quality Gate](https://sonarcloud.io/api/project_badges/measure?project=sebastiandine_Card-Collection-Manager-3&metric=alert_status)](https://sonarcloud.io/summary/new_code?id=sebastiandine_Card-Collection-Manager-3)
+[![SonarQube Cloud](https://sonarcloud.io/images/project_badges/sonarcloud-dark.svg)](https://sonarcloud.io/summary/new_code?id=sebastiandine_Card-Collection-Manager-3)
 
 Card Collection Manager 3 is an extensible desktop application for managing trading card game collections. It is designed as a practical way to track cards and manage per-card images for large collections, with local per-game data, set synchronization workflows, and a desktop-first UX. The app preserves the established JSON layout from earlier CCM versions so existing collections stay compatible.
 

ui_wx/src/SvgIcons.cpp

@@ -4,7 +4,6 @@
 #include <wx/image.h>
 
 #include <algorithm>
-#include <cstring>
 #include <string>
 #include <string_view>
 
@@ -68,12 +67,14 @@ namespace {
 
 // Substitute every "@FILL@" occurrence in `tmpl` with `fill`.
 std::string applyFill(const char* tmpl, const char* fill) {
-    std::string s(tmpl);
+    std::string s = tmpl != nullptr ? tmpl : "";
     constexpr std::string_view kPlaceholder = "@FILL@";
+    const std::string_view fillView = fill != nullptr ? std::string_view(fill)
+                                                      : std::string_view{};
     for (std::string::size_type pos = s.find(kPlaceholder);
          pos != std::string::npos;
-         pos = s.find(kPlaceholder, pos + std::strlen(fill))) {
-        s.replace(pos, kPlaceholder.size(), fill);
+         pos = s.find(kPlaceholder, pos + fillView.size())) {
+        s.replace(pos, kPlaceholder.size(), fillView);
     }
     return s;
 }