Merge branch 'master' into jgrpp

# Conflicts:
#	.github/workflows/ci-build.yml
#	.github/workflows/codeql.yml
#	.github/workflows/commit-checker.yml
#	.github/workflows/release-linux-legacy.yml
#	.github/workflows/release-linux.yml
#	.github/workflows/release-macos.yml
#	.github/workflows/release-windows-store.yml
#	.github/workflows/release-windows.yml
#	.github/workflows/upload-cdn.yml
#	.github/workflows/upload-gog.yml
#	.github/workflows/upload-steam.yml
#	src/console_cmds.cpp
#	src/core/math_func.hpp
#	src/fios.cpp
#	src/fios.h
#	src/intro_gui.cpp
#	src/network/network_server.cpp
#	src/openttd.cpp
#	src/settings.cpp
#	src/settings_gui.cpp
#	src/settings_internal.h
#	src/settings_table.cpp
#	src/settings_type.h
#	src/table/settings.h.preamble
#	src/table/settings/company_settings.ini
#	src/table/settings/currency_settings.ini
#	src/table/settings/difficulty_settings.ini
#	src/table/settings/economy_settings.ini
#	src/table/settings/game_settings.ini
#	src/table/settings/gui_settings.ini
#	src/table/settings/linkgraph_settings.ini
#	src/table/settings/locale_settings.ini
#	src/table/settings/misc_settings.ini
#	src/table/settings/multimedia_settings.ini
#	src/table/settings/network_private_settings.ini
#	src/table/settings/network_settings.ini
#	src/table/settings/news_display_settings.ini
#	src/table/settings/old_gameopt_settings.ini
#	src/table/settings/pathfinding_settings.ini
#	src/table/settings/script_settings.ini
#	src/table/settings/win32_settings.ini
#	src/table/settings/window_settings.ini
#	src/table/settings/world_settings.ini
#	src/viewport.cpp
#	src/viewport_func.h
#	src/window.cpp

src/string.cpp

@@ -1069,6 +1069,55 @@ static int ICUStringContains(const std::string_view str, const std::string_view
 	return ci_str.find(ci_value) != CaseInsensitiveStringView::npos;
 }
 
+/**
+ * Convert a single hex-nibble to a byte.
+ *
+ * @param c The hex-nibble to convert.
+ * @return The byte the hex-nibble represents, or -1 if it is not a valid hex-nibble.
+ */
+static int ConvertHexNibbleToByte(char c)
+{
+	if (c >= '0' && c <= '9') return c - '0';
+	if (c >= 'A' && c <= 'F') return c + 10 - 'A';
+	if (c >= 'a' && c <= 'f') return c + 10 - 'a';
+	return -1;
+}
+
+/**
+ * Convert a hex-string to a byte-array, while validating it was actually hex.
+ *
+ * @param hex The hex-string to convert.
+ * @param bytes The byte-array to write the result to.
+ *
+ * @note The length of the hex-string has to be exactly twice that of the length
+ * of the byte-array, otherwise conversion will fail.
+ *
+ * @return True iff the hex-string was valid and the conversion succeeded.
+ */
+bool ConvertHexToBytes(std::string_view hex, std::span<uint8_t> bytes)
+{
+	if (bytes.size() != hex.size() / 2) {
+		return false;
+	}
+
+	/* Hex-string lengths are always divisible by 2. */
+	if (hex.size() % 2 != 0) {
+		return false;
+	}
+
+	for (size_t i = 0; i < hex.size() / 2; i++) {
+		auto hi = ConvertHexNibbleToByte(hex[i * 2]);
+		auto lo = ConvertHexNibbleToByte(hex[i * 2 + 1]);
+
+		if (hi < 0 || lo < 0) {
+			return false;
+		}
+
+		bytes[i] = (hi << 4) | lo;
+	}
+
+	return true;
+}
 
 #ifdef WITH_UNISCRIBE