Fix: FormatArrayAsHex returns gibberish instead of a hex array

src/string.cpp

@@ -135,14 +135,14 @@ char *stredup(const char *s, const char *last)
  */
 std::string FormatArrayAsHex(span<const byte> data)
 {
-	std::ostringstream ss;
-	ss << std::uppercase << std::setfill('0') << std::setw(2) << std::hex;
+	std::string str;
+	str.reserve(data.size() * 2 + 1);
 
 	for (auto b : data) {
-		ss << b;
+		fmt::format_to(std::back_inserter(str), "{:02X}", b);
 	}
 
-	return ss.str();
+	return str;
 }
 
 /**

src/tests/string_func.cpp

@@ -12,6 +12,7 @@
 #include "../3rdparty/catch2/catch.hpp"
 
 #include "../string_func.h"
+#include <array>
 
 /**** String compare/equals *****/
 
@@ -516,3 +517,11 @@ TEST_CASE("StrEndsWithIgnoreCase - std::string_view")
 	CHECK(!StrEndsWithIgnoreCase(base.substr(2, 1), base.substr(0, 1)));
 	CHECK(!StrEndsWithIgnoreCase(base.substr(0, 1), base.substr(0, 2)));
 }
+
+
+TEST_CASE("FormatArrayAsHex")
+{
+	CHECK(FormatArrayAsHex(std::array<byte, 0>{}) == "");
+	CHECK(FormatArrayAsHex(std::array<byte, 1>{0x12}) == "12");
+	CHECK(FormatArrayAsHex(std::array<byte, 4>{0x13, 0x38, 0x42, 0xAF}) == "133842AF");
+}