Empty RenderTexture after recreating window

[JaagupAverin]

Subject of the issue

Recreating RenderWindow causes Texts in RenderTexture to disappear.

Your environment

Windows 10,
SFML 2.5.2
MSVC C++17

Steps to reproduce

Compile and run the following code. Notice the commented line.

#include <SFML/Graphics.hpp>
#include <assert.h>

const sf::Vector2f CENTER{ 250.f, 250.f };
const std::string FONT_PATH = "fira_medium.ttf";

int main()
{
    sf::RenderWindow window{ sf::VideoMode(500u, 500u), "bug" };

    sf::Font font;
    assert(font.loadFromFile(FONT_PATH));

    sf::RenderTexture texts_rt;
    texts_rt.create(300u, 300u);

    sf::Sprite texts_sprite;
    texts_sprite.setOrigin(sf::Vector2f(150.f, 150.f));
    texts_sprite.setPosition(CENTER);
    texts_sprite.setTexture(texts_rt.getTexture());

    std::vector<sf::Text> texts;
    auto draw_texts_to_texture = [&]()
    {
        texts_rt.clear(sf::Color::Red);
        for (auto& text : texts)
            texts_rt.draw(text);
        texts_rt.display();
    };

    auto append_text = [&](const std::string& str) 
    {
        sf::Text text;
        text.setString(str);
        text.setFillColor(sf::Color::White);
        text.setOutlineColor(sf::Color::Black);
        text.setOutlineThickness(2.f);
        text.setFont(font);
        text.setCharacterSize(16u);
        text.setPosition(sf::Vector2f(10.f, texts.size() * 24.f));
        texts.emplace_back(std::move(text));

        draw_texts_to_texture();
    };
    append_text("Text should always be visible.");
    append_text("Press TAB to recreate window.");

    while (window.isOpen())
    {
        for (sf::Event event; window.pollEvent(event);)
        {
            if (event.type == sf::Event::Closed)
                window.close();
            else if (event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Tab)
            {
                window.create(sf::VideoMode(500u, 500u), "bug");
                append_text("Recreated Window."); // If we comment this out, there is no problem!
            }
        }

        window.clear(sf::Color::Black);
        window.draw(texts_sprite);
        window.display();
    }
}

Expected behavior

Nothing to change.

Actual behavior

The texts disappear.

[binary1248]

This should be fixed in #1630.