Fuzz fail (#1097)

fix failing fuzz case involving binary string with a '\x' in it.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

tests/FuzzFailTest.cpp

@@ -260,3 +260,33 @@ TEST_CASE("fuzz_config_test1") {
     CHECK(app->get_option_no_throw("--new_flag") != nullptr);
     CHECK(app->get_option_no_throw("--new_vector") != nullptr);
 }
+
+// this test uses the same tests as above just with a full roundtrip test
+TEST_CASE("app_roundtrip_custom") {
+    CLI::FuzzApp fuzzdata;
+    CLI::FuzzApp fuzzdata2;
+    auto app = fuzzdata.generateApp();
+    auto app2 = fuzzdata2.generateApp();
+    int index = GENERATE(range(1, 3));
+    std::string optionString, flagString;
+    auto parseData = loadFailureFile("round_trip_custom", index);
+    std::size_t pstring_start{0};
+    pstring_start = fuzzdata.add_custom_options(app.get(), parseData);
+
+    if(pstring_start > 0) {
+        app->parse(parseData.substr(pstring_start));
+    } else {
+        app->parse(parseData);
+    }
+
+    // should be able to write the config to a file and read from it again
+    std::string configOut = app->config_to_str();
+    app->clear();
+    std::stringstream out(configOut);
+    if(pstring_start > 0) {
+        fuzzdata2.add_custom_options(app2.get(), parseData);
+    }
+    app2->parse_from_stream(out);
+    auto result = fuzzdata2.compare(fuzzdata);
+    CHECK(result);
+}

tests/HelpersTest.cpp

@@ -301,6 +301,42 @@ TEST_CASE("StringTools: binaryEscapseConversion2", "[helpers]") {
     CHECK(rstring == testString);
 }
 
+TEST_CASE("StringTools: binaryEscapseConversion_withX", "[helpers]") {
+    std::string testString("hippy\\x35mm\\XF3_helpX26fox19");
+    testString.push_back(0);
+    testString.push_back(0);
+    testString.push_back(0);
+    testString.push_back(56);
+    testString.push_back(-112);
+    testString.push_back(-112);
+    testString.push_back(39);
+    testString.push_back(97);
+    std::string estring = CLI::detail::binary_escape_string(testString);
+    CHECK(CLI::detail::is_binary_escaped_string(estring));
+    std::string rstring = CLI::detail::extract_binary_string(estring);
+    CHECK(rstring == testString);
+}
+
+TEST_CASE("StringTools: binaryEscapseConversion_withBrackets", "[helpers]") {
+
+    std::string vstr = R"raw('B"([\xb0\x0a\xb0/\xb0\xb0\xb0\xb0\xb0\xb0\xb0\xb0\xb0\xb0\xb0\xb0\xb0])"')raw";
+    std::string testString("[");
+    testString.push_back(-80);
+    testString.push_back('\n');
+    testString.push_back(-80);
+    testString.push_back('/');
+    for(int ii = 0; ii < 13; ++ii) {
+        testString.push_back(-80);
+    }
+    testString.push_back(']');
+
+    std::string estring = CLI::detail::binary_escape_string(testString);
+    CHECK(CLI::detail::is_binary_escaped_string(estring));
+    CHECK(estring == vstr);
+    std::string rstring = CLI::detail::extract_binary_string(estring);
+    CHECK(rstring == testString);
+}
+
 TEST_CASE("StringTools: binaryStrings", "[helpers]") {
     std::string rstring = "B\"()\"";
     CHECK(CLI::detail::extract_binary_string(rstring).empty());

tests/fuzzFail/round_trip_custom2

@@ -0,0 +1 @@
+--vM=[ｰ