add a test to cover the fix to find_key's infinite loop/crash

Adds a test with a schema example containing a super cycle and a .cfg file containing an unknown key to this schema. Previously, this would cause an infinite loop or crash. Now an exception for invalid key should be thrown.

boost_test_schedule

@@ -263,3 +263,4 @@ feature_test_WML_macro_define/macro_define_noArgument_ParseAsExpected
 feature_test_WML_macro_define/macro_define_1Argument_ParseAsExpected
 test_schema_self_validator/test_schema_super_self_reference
 test_schema_self_validator/test_schema_super_cycle
+test_schema_validator/test_super_cycle_crashes_on_unknown_key

projectfiles/CodeBlocks/tests.cbp

@@ -1227,6 +1227,7 @@
 		<Unit filename="../../src/tests/utils/wml_equivalence.cpp" />
 		<Unit filename="../../src/tests/utils/wml_equivalence.hpp" />
 		<Unit filename="../../src/tests/wml/test_macro_define.cpp" />
+		<Unit filename="../../src/tests/wml/schema/test_schema_validator.cpp" />
 		<Unit filename="../../src/tests/wml/schema/test_schema_self_validator.cpp" />
 		<Unit filename="../../src/theme.cpp" />
 		<Unit filename="../../src/theme.hpp" />

projectfiles/Xcode/The Battle for Wesnoth.xcodeproj/project.pbxproj

@@ -661,6 +661,7 @@
 		62D24F321519987400350848 /* context_manager.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 62D24F311519987400350848 /* context_manager.cpp */; };
 		62D24F351519995200350848 /* palette_manager.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 62D24F341519995200350848 /* palette_manager.cpp */; };
 		6D574EACA3483ABEE72819F0 /* statistics_record.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 27764FB68F02032F1C0B6748 /* statistics_record.cpp */; };
+		7A7146D7893AA09891352019 /* test_schema_validator.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 7CF14AB694764953E2CB3AF7 /* test_schema_validator.cpp */; };
 		77D94146A5FA29849D1A9BD8 /* multiline_text.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 0B0F48CE9CF65D9813BE6CDC /* multiline_text.cpp */; };
 		7BFC4DF5BFF8CF75855BA662 /* prompt.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 67044415B63F5888193BD7A6 /* prompt.cpp */; };
 		7FDF4E8D9C94E7DA8F41F7BB /* tod_new_schedule.hpp in Headers */ = {isa = PBXBuildFile; fileRef = 5D46466DBCD81B13621C7342 /* tod_new_schedule.hpp */; };
@@ -2195,6 +2196,7 @@
 		67044415B63F5888193BD7A6 /* prompt.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = prompt.cpp; sourceTree = "<group>"; };
 		6FA542D78393E8FF067775DA /* edit_pbl.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = edit_pbl.cpp; sourceTree = "<group>"; };
 		755D4555A1DEA29125E7F338 /* scroll_text.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; name = scroll_text.cpp; path = scroll_text.cpp; sourceTree = "<group>"; };
+		7CF14AB694764953E2CB3AF7 /* test_schema_validator.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; name = test_schema_validator.cpp; path = test_schema_validator.cpp; sourceTree = "<group>"; };
 		84234C54BB84519421FD4136 /* general.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = general.cpp; sourceTree = "<group>"; };
 		8D1107310486CEB800E47090 /* Info.plist */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		8D1107320486CEB800E47090 /* The Battle for Wesnoth.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = "The Battle for Wesnoth.app"; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -3162,6 +3164,7 @@
 			isa = PBXGroup;
 			children = (
 				26A04033A9545CFE8A226FBD /* test_schema_self_validator.cpp */,
+				7CF14AB694764953E2CB3AF7 /* test_schema_validator.cpp */,
 			);
 			path = schema;
 			sourceTree = "<group>";
@@ -6580,6 +6583,7 @@
 				E6CF415F9FD04C35A55FB24D /* scroll_text.cpp in Sources */,
 				62714C2FBE84B66CF14E3722 /* test_sdl.cpp in Sources */,
 				529242A8856DE8D00988B9BD /* test_schema_self_validator.cpp in Sources */,
+				7A7146D7893AA09891352019 /* test_schema_validator.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

source_lists/boost_unit_tests

@@ -31,4 +31,5 @@ tests/utils/fake_display.cpp
 tests/utils/game_config_manager_tests.cpp
 tests/utils/wml_equivalence.cpp
 tests/wml/test_macro_define.cpp
+tests/wml/schema/test_schema_validator.cpp
 tests/wml/schema/test_schema_self_validator.cpp

src/tests/wml/schema/test_schema_validator.cpp

@@ -0,0 +1,59 @@
+/*
+	Copyright (C) 2003 - 2023
+	Part of the Battle for Wesnoth Project https://www.wesnoth.org/
+
+	This program is free software; you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation; either version 2 of the License, or
+	(at your option) any later version.
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY.
+
+	See the COPYING file for more details.
+	COPYING file for more details.
+*/
+
+#define GETTEXT_DOMAIN "wesnoth-test"
+
+#include <boost/test/unit_test.hpp>
+
+#include <boost/algorithm/string/predicate.hpp>
+
+#include "game_version.hpp"
+#include "serialization/parser.hpp"
+#include "serialization/preprocessor.hpp"
+#include "serialization/schema_validator.hpp"
+#include "wml_exception.hpp"
+
+BOOST_AUTO_TEST_SUITE( test_schema_validator )
+
+BOOST_AUTO_TEST_CASE( test_super_cycle_crashes_on_unknown_key )
+{
+	constexpr auto schema_path =  "src/tests/wml/schema/test_schema_validator/test_schema_super_cycle.cfg";
+	constexpr auto config_path = "src/tests/wml/schema/test_schema_validator/test_super_cycle_crashes_on_unknown_key.cfg";
+
+	auto validator = schema_validation::schema_validator(schema_path, false);
+
+	validator.set_create_exceptions(true);
+
+	preproc_map defines_map;
+	defines_map["WESNOTH_VERSION"] = preproc_define(game_config::wesnoth_version.str());
+	defines_map["SCHEMA_VALIDATION"] = preproc_define();
+
+	auto stream = preprocess_file(config_path, &defines_map);
+
+	config result;
+
+	BOOST_CHECK_EXCEPTION(
+		read(result, *stream, &validator),
+		wml_exception,
+		[] (const wml_exception& e) {
+			return boost::algorithm::contains(
+				e.dev_message,
+				"Invalid key 'unknown=' in tag [first]"
+			);
+		}
+	);
+}
+
+BOOST_AUTO_TEST_SUITE_END()

src/tests/wml/schema/test_schema_validator/test_schema_super_cycle.cfg

@@ -0,0 +1,23 @@
+[wml_schema]
+	[tag]
+		name="root"
+		[tag]
+			name="main"
+			[tag]
+				name="first"
+				super="second"
+			[/tag]
+		[/tag]
+		[tag]
+			name="other"
+			[tag]
+				name="second"
+				super="main/first"
+			[/tag]
+		[/tag]
+		[tag]
+			name="second"
+			super="other/second"
+		[/tag]
+	[/tag]
+[/wml_schema]

src/tests/wml/schema/test_schema_validator/test_super_cycle_crashes_on_unknown_key.cfg

@@ -0,0 +1,11 @@
+[main]
+	[first]
+		unknown="1"
+	[/first]
+[/main]
+[other]
+	[second]
+	[/second]
+[/other]
+[second]
+[/second]