test: Add test cases for image with empty dimensions (#702)

Test fix #649

test/core/image/CMakeLists.txt

@@ -7,7 +7,8 @@
 #
 foreach(_name
   concepts
-  image)
+  image
+  empty_dimensions)
   set(_test t_core_image_${_name})
   set(_target test_core_image_${_name})
 

test/core/image/Jamfile

@@ -11,3 +11,4 @@ import testing ;
 compile concepts.cpp ;
 
 run image.cpp ;
+run empty_dimensions.cpp ;

test/core/image/empty_dimensions.cpp

@@ -0,0 +1,91 @@
+//
+// Copyright 2019-2020 Mateusz Loskot <mateusz at loskot dot net>
+//
+// Distributed under the Boost Software License, Version 1.0
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+//
+#include <boost/gil.hpp>
+
+#include <boost/core/lightweight_test.hpp>
+
+#include "test_fixture.hpp"
+#include "test_utility_output_stream.hpp"
+#include "core/pixel/test_fixture.hpp"
+
+namespace gil = boost::gil;
+namespace fixture = boost::gil::test::fixture;
+
+// Test cases of memory leak potential for image created with empty dimesions,
+// see https://github.com/boostorg/gil/pull/649
+// The main goal of these test cases is to trigger any memory leak detectors.
+
+void test_default_constructor()
+{
+    boost::gil::rgb8_image_t image;
+    BOOST_TEST_EQ(image.width(), 0);
+    BOOST_TEST_EQ(image.height(), 0);
+}
+
+void test_copy_constructor_with_empty_image()
+{
+    boost::gil::rgb8_image_t image1;
+    boost::gil::rgb8_image_t image2(image1);
+    BOOST_TEST_EQ(image2.width(), 0);
+    BOOST_TEST_EQ(image2.height(), 0);
+}
+
+struct test_constructor_with_empty_dimensions
+{
+    template <typename Image>
+    void operator()(Image const &)
+    {
+        using image_t = Image;
+        image_t image(0, 0);
+        BOOST_TEST_EQ(image.width(), 0);
+        BOOST_TEST_EQ(image.height(), 0);
+    }
+
+    static void run()
+    {
+        boost::mp11::mp_for_each<fixture::image_types>(test_constructor_with_empty_dimensions{});
+    }
+};
+
+struct test_constructor_with_empty_dimensions_with_pixel
+{
+    template <typename Image>
+    void operator()(Image const &)
+    {
+        using image_t = Image;
+        gil::point_t const dimensions{0, 0};
+        using pixel_t = typename image_t::view_t::value_type;
+        pixel_t const rnd_pixel = fixture::pixel_generator<pixel_t>::random();
+        image_t image(dimensions, rnd_pixel);
+        BOOST_TEST_EQ(image.width(), dimensions.x);
+        BOOST_TEST_EQ(image.height(), dimensions.y);
+
+        bool none_visited = true;
+        for (pixel_t const &p : gil::view(image))
+        {
+            none_visited = false;
+            BOOST_TEST_EQ(p, rnd_pixel);
+        }
+        BOOST_TEST(none_visited);
+    }
+
+    static void run()
+    {
+        boost::mp11::mp_for_each<fixture::image_types>(test_constructor_with_empty_dimensions_with_pixel{});
+    }
+};
+
+int main()
+{
+    test_default_constructor();
+    test_copy_constructor_with_empty_image();
+    test_constructor_with_empty_dimensions::run();
+    test_constructor_with_empty_dimensions_with_pixel::run();
+
+    return ::boost::report_errors();
+}