Fix parsing of `4.` in Expression

(cherry picked from commit 905e8a39bfa635e858d1c691161b5869d5bcc35f)

core/math/expression.cpp

@@ -1103,7 +1103,9 @@ Error Expression::_get_token(Token &r_token) {
 						is_first_char = false;
 					}
 
-					str_ofs--;
+					if (c != 0) {
+						str_ofs--;
+					}
 
 					r_token.type = TK_CONSTANT;
 

main/tests/test_expression.cpp

@@ -0,0 +1,136 @@
+/**************************************************************************/
+/*  test_expression.cpp                                                   */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#include "test_expression.h"
+
+#include "core/math/expression.h"
+#include "core/os/os.h"
+
+#define CHECK_MESSAGE(X, msg)                                      \
+	if (!(X)) {                                                    \
+		OS::get_singleton()->print("\tFAIL at %s: %s\n", #X, msg); \
+		return false;                                              \
+	} else {                                                       \
+		OS::get_singleton()->print("\tPASS\n");                    \
+	}
+
+namespace TestExpression {
+
+bool floating_point_notation() {
+	OS::get_singleton()->print("\n\nTest 1: Floating-point notation\n");
+
+	Expression expression;
+
+	CHECK_MESSAGE(
+			expression.parse("2.") == OK,
+			"The expression should parse successfully.");
+	CHECK_MESSAGE(
+			Math::is_equal_approx(expression.execute(Array()), 2.0),
+			"The expression should return the expected result.");
+
+	CHECK_MESSAGE(
+			expression.parse("(2.)") == OK,
+			"The expression should parse successfully.");
+	CHECK_MESSAGE(
+			Math::is_equal_approx(expression.execute(Array()), 2.0),
+			"The expression should return the expected result.");
+
+	CHECK_MESSAGE(
+			expression.parse(".3") == OK,
+			"The expression should parse successfully.");
+	CHECK_MESSAGE(
+			Math::is_equal_approx(expression.execute(Array()), 0.3),
+			"The expression should return the expected result.");
+
+	CHECK_MESSAGE(
+			expression.parse("2.+5.") == OK,
+			"The expression should parse successfully.");
+	CHECK_MESSAGE(
+			Math::is_equal_approx(expression.execute(Array()), 7.0),
+			"The expression should return the expected result.");
+
+	CHECK_MESSAGE(
+			expression.parse(".3-.8") == OK,
+			"The expression should parse successfully.");
+	CHECK_MESSAGE(
+			Math::is_equal_approx(expression.execute(Array()), -0.5),
+			"The expression should return the expected result.");
+
+	CHECK_MESSAGE(
+			expression.parse("2.+.2") == OK,
+			"The expression should parse successfully.");
+	CHECK_MESSAGE(
+			Math::is_equal_approx(expression.execute(Array()), 2.2),
+			"The expression should return the expected result.");
+
+	CHECK_MESSAGE(
+			expression.parse(".0*0.") == OK,
+			"The expression should parse successfully.");
+	CHECK_MESSAGE(
+			Math::is_equal_approx(expression.execute(Array()), 0.0),
+			"The expression should return the expected result.");
+
+	return true;
+}
+
+typedef bool (*TestFunc)();
+
+TestFunc test_funcs[] = {
+	floating_point_notation,
+	nullptr
+};
+
+MainLoop *test() {
+	int count = 0;
+	int passed = 0;
+
+	while (true) {
+		if (!test_funcs[count]) {
+			break;
+		}
+		bool pass = test_funcs[count]();
+		if (pass) {
+			passed++;
+		}
+		OS::get_singleton()->print("\t%s\n", pass ? "PASS" : "FAILED");
+
+		count++;
+	}
+
+	OS::get_singleton()->print("\n\n\n");
+	OS::get_singleton()->print("*************\n");
+	OS::get_singleton()->print("***TOTALS!***\n");
+	OS::get_singleton()->print("*************\n");
+
+	OS::get_singleton()->print("Passed %i of %i tests\n", passed, count);
+
+	return nullptr;
+}
+} // namespace TestExpression

main/tests/test_expression.h

@@ -0,0 +1,41 @@
+/**************************************************************************/
+/*  test_expression.h                                                     */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef TEST_EXPRESSION_H
+#define TEST_EXPRESSION_H
+
+#include "core/os/main_loop.h"
+
+namespace TestExpression {
+
+MainLoop *test();
+}
+
+#endif // TEST_EXPRESSION_H

main/tests/test_main.cpp

@@ -37,6 +37,7 @@
 #include "test_astar.h"
 #include "test_basis.h"
 #include "test_crypto.h"
+#include "test_expression.h"
 #include "test_gdscript.h"
 #include "test_gui.h"
 #include "test_math.h"
@@ -71,6 +72,7 @@ const char **tests_get_names() {
 		"astar",
 		"xml_parser",
 		"theme",
+		"expression",
 		nullptr
 	};
 
@@ -156,6 +158,10 @@ MainLoop *test_main(String p_test, const List<String> &p_args) {
 		return TestTheme::test();
 	}
 
+	if (p_test == "expression") {
+		return TestExpression::test();
+	}
+
 	print_line("Unknown test: " + p_test);
 	return nullptr;
 }