System Information

OpenCV 4.11.0

Detailed description

In the following code https://github.com/sturkmen72/opencv/blob/538b99f9f3e3b89cfdc363f8afc7ad4cf21b0ba0/modules/imgcodecs/src/grfmt_webp.cpp

/grfmt_webp.cpp)

bool WebPDecoder::readData(Mat &img)
{
    ...
    if (m_has_animation)
    {
        uint8_t* buf;
        int timestamp;

        WebPAnimDecoderGetNext(anim_decoder.get(), &buf, &timestamp);
        Mat tmp(Size(m_width, m_height), CV_8UC4, buf);
        ...

buf and timestamp can remain uninitialized if WebPAnimDecoderGetNext() fails.
buf should be checked before going any further.

Steps to reproduce

Compiling with VIsual studio raises a warning about potential use of uninitialized variable

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues, forum.opencv.org, Stack Overflow, etc and have not found any solution
• I updated to the latest OpenCV version and the issue is still there
• There is reproducer code and related data files (videos, images, onnx, etc)