Some trivial XCB bugs

[jcowgill]

Found with clang static code analyzer:

https://github.com/LaurentGomila/SFML/blob/master/src/SFML/Window/Unix/InputImpl.cpp#L205

src/SFML/Window/Unix/InputImpl.cpp:205:31: warning: Value stored to 'result' is never read
        case Mouse::Left:     result = pointer->mask & XCB_BUTTON_MASK_1;
                              ^        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/SFML/Window/Unix/InputImpl.cpp:206:31: warning: Value stored to 'result' is never read
        case Mouse::Right:    result = pointer->mask & XCB_BUTTON_MASK_3;
                              ^        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/SFML/Window/Unix/InputImpl.cpp:207:31: warning: Value stored to 'result' is never read
        case Mouse::Middle:   result = pointer->mask & XCB_BUTTON_MASK_2;
                              ^        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

https://github.com/LaurentGomila/SFML/blob/master/src/SFML/Window/Unix/WindowImplX11.cpp#L538

src/SFML/Window/Unix/WindowImplX11.cpp:538:73: warning: Use of memory after it is freed
        err() << "Failed to set the window's icon: Error code " << (int)errptr->error_code << std::endl;
                                                                        ^~~~~~~~~~~~~~~~~~

[LaurentGomila]

Thanks.

The first one is less obvious: the "break" statements are missing. It would be much better like this:

    // Get pointer mask
    xcb_query_pointer_reply_t* pointer = xcb_query_pointer_reply(connection, xcb_query_pointer(connection, XDefaultRootWindow(display)), NULL);
    uint16_t mask = pointer->mask;
    free(pointer);

    // Close the connection with the X server
    CloseDisplay(display);

    switch (button)
    {
        case Mouse::Left:     return mask & XCB_BUTTON_MASK_1;
        case Mouse::Right:    return mask & XCB_BUTTON_MASK_3;
        case Mouse::Middle:   return mask & XCB_BUTTON_MASK_2;
        case Mouse::XButton1: return false; // not supported by X
        case Mouse::XButton2: return false; // not supported by X
        default:              return false;
    }

[kimci86]

@LaurentGomila
I guess you meant to return mask & ... instead of pointer->mask & ...

[LaurentGomila]

Oops 😁